Vaccines

17 pages, 607 KB

Open AccessReview

Construction and Research Progress of Animal Models and Mouse Adapted Strains of Seasonal Influenza Virus

by Haijun Zhu, Siyu Pu, Peiqing He, Junhao Luo and Rongbao Gao

Vaccines 2025, 13(10), 1077; https://doi.org/10.3390/vaccines13101077 - 21 Oct 2025

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Influenza viruses, featured by high variability, pose a persistent public health threat because of an annual seasonal epidemic in the world and irregular global pandemic, requiring animal models to elucidate their pathogenic mechanisms and advance preventive strategies. Mice have been selected as the [...] Read more.

Influenza viruses, featured by high variability, pose a persistent public health threat because of an annual seasonal epidemic in the world and irregular global pandemic, requiring animal models to elucidate their pathogenic mechanisms and advance preventive strategies. Mice have been selected as the primary animal model, although several experimental animals have been used in studies of the influenza virus. However, the limited susceptibility of wild-type influenza viruses to mice poses significant challenges for studying pathogenesis and intervention strategies. Here, to help understand the construction of mouse-adapted influenza viruses, we reviewed the recent research progress in constructing mouse-adapted influenza virus strains to overcome species-specific barriers. Full article

(This article belongs to the Special Issue Immunity to Influenza Viruses and Vaccines)

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22 pages, 8808 KB

Open AccessArticle

Efficacy of a Novel PCV2d and Mycoplasma hyopneumoniae Combined Vaccine in Piglets with High and Low Levels of PCV2 Maternally Derived Antibodies at Vaccination

by Mònica Sagrera, Laura Garza-Moreno, Àlex Cobos, Anna Maria Llorens, Eva Huerta, Mónica Pérez, Diego Pérez, David Espigares, Joaquim Segalés and Marina Sibila

Vaccines 2025, 13(10), 1076; https://doi.org/10.3390/vaccines13101076 - 21 Oct 2025

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Abstract

Background/Objectives: Maternally derived antibody (MDA) levels of porcine circovirus 2 (PCV2) may eventually interfere with humoral response and vaccination efficacy. This study aimed to evaluate the efficacy of a ready-to-use PCV2d and Mycoplasma hyopneumoniae combined vaccine in piglets with different PCV2 MDA levels [...] Read more.

Background/Objectives: Maternally derived antibody (MDA) levels of porcine circovirus 2 (PCV2) may eventually interfere with humoral response and vaccination efficacy. This study aimed to evaluate the efficacy of a ready-to-use PCV2d and Mycoplasma hyopneumoniae combined vaccine in piglets with different PCV2 MDA levels at vaccination in an experimental inoculation with a heterologous viral genotype. Methods: Forty-eight piglets were allocated into vaccinated (V) and non-vaccinated (NV) groups with high (H) and low (L) PCV2 MDA subgroups (H-V, H-NV, L-V, L-NV). At 3 weeks of age, the piglets received either one dose of vaccine or placebo. Five weeks later, all animals were intranasally challenged with a PCV2b inoculum. Body weight was registered at different time points. Blood samples, peripheral blood mononuclear cells and tracheobronchial lymph nodes (TBLN) were collected and used to assess viraemia, viral load, humoral and cellular responses and histological lesions. Results: The V group showed higher PCV2 antibody levels from challenge onwards, along with a lower percentage of viraemic pigs and reduced viral load in serum at 2 and 3 weeks post-challenge (wpc) and in TBLN tissues compared to the NV group. The H-V group had the highest antibody levels post-challenge, showed no detectable viraemia and had a lower overall amount of virus in tissues. The NV group (especially H-NV) exhibited increased levels of IFN-γ, IFN-α and TNF-α post-challenge. Conclusions: The tested vaccine elicited humoral and cellular immune responses and reduced viral presence in serum and tissues, demonstrating efficacy in a PCV2 subclinical infection model despite high MDA levels at the time of vaccination. Understanding both humoral and cellular immune responses according to different MDA levels can help design more effective vaccination strategies against PCV2. Full article

(This article belongs to the Section Veterinary Vaccines)

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24 pages, 3538 KB

Open AccessTechnical Note

Improving the Suitability of Vaccine Design for Immunisation Programmes and Enhancing Vaccine Policy Quality Through User Research

by Stefano Malvolti, Melissa Malhame, Adam Soble, Carsten Mantel, Melissa Ko, Lorena Perrin, Tiziana Scarna, Marion Menozzi-Arnaud and Jean-Pierre Amorij

Vaccines 2025, 13(10), 1075; https://doi.org/10.3390/vaccines13101075 - 21 Oct 2025

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Abstract

Background: The achievement of the goals of the Immunization Agenda 2030 (IA2030) requires vaccines to be developed and implemented that meet the needs and requirements of the final users: vaccinators and vaccinees. A detailed and shared understanding of these needs should inform policy [...] Read more.

Background: The achievement of the goals of the Immunization Agenda 2030 (IA2030) requires vaccines to be developed and implemented that meet the needs and requirements of the final users: vaccinators and vaccinees. A detailed and shared understanding of these needs should inform policy and programme guidance directing stakeholders’ efforts and investments. Currently, relevant guidance documents only partially capture vaccine users’ perspectives. Method: To help overcome this gap, we propose an operational research method grounded in the principles of the design approach that systematically maps and integrates user perspectives in vaccine development, policy, and implementation decisions. Results: The method, named the seven Ws, guides researchers through a three-step process. First, it clarifies the contribution of a vaccine to solving a public health problem—the solution–problem fit. Second, it maps potential implementation strategies for the vaccine in different settings. Lastly, it describes the relevant vaccine’s use cases across the implementation strategies, elucidating the user requirements for the vaccine to be successfully implemented—the solution–provider and solution–user fits. Conclusions: By explicitly pursuing these three fits, policymakers, vaccine developers, and programme managers will be able to better contribute towards the achievement of the IA2030 goals. This framework is intended as a conceptual contribution rather than an empirical validation study. Full article

(This article belongs to the Special Issue Promoting Research, Development and Access to Vaccines to Address Global Inequities)

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17 pages, 574 KB

Open AccessArticle

Impact of SARS-CoV-2 Vaccination on Disease Activity and Severity of COVID-19 Infection in Patients with Systemic Lupus Erythematosus: A Multicenter Cohort Study

by Natália Sarzi Sartori, Ketty Lysie Libardi Lira Machado, Samira Tatiyama Miyamoto, Flavia Zon Pretti, Maria da Penha Gomes Gouveia, Yasmin Gurtler Pinheiro de Oliveira, Vanezia Gonçalves da Silva, Filipe Faé, Ana Paula Neves Burian, Karina Rosemarie Lallemand Tapia, Anna Carolina Simões Moulin, Luiza Lorenzoni Grillo, Paula dos Santos Athayde, Helena da Silva Corona, Sabrina de Souza Ramos, Flávia Maria Matos Melo Campos Peixoto, Priscila Dias Cardoso Ribeiro, Vanessa de Oliveira Magalhães, Mariana Freitas de Aguiar, Erika Biegelmeyer, Cristiane Kayser, Alexandre Wagner Silva De Souza, Charlles Heldan de Moura Castro, Juliana Bühring, Sandra Lúcia Euzébio Ribeiro, Sérgio Henrique Oliveira dos Santos, Clara Pinheiro Martins, Jonathan Willian da Silva Rodrigues, Marcos Mavignier Sousa Dias, Bruna Guimarães Dutra, Camila Maria Paiva França Telles, Samuel Elias Basualto Dias, Rodrigo Poubel Vieira de Rezende, Katia Lino Baptista, Rodrigo Cutrim Gaudio, Ana Karla Guedes de Melo, Valéria Bezerra da Silva, Vitor Alves Cruz, Jozelia Rêgo, Rejane Maria Rodrigues de Abreu Vieira, Adah Sophia Rodrigues Vieira, Adriana Maria Kakehasi, Anna Carolina Faria Moreira Gomes Tavares, Artur José Azevedo Pereira, Pollyana Vitoria Thomaz da Costa, Valderilio Feijó Azevedo, Nicole Pamplona Bueno de Andrade, Guilherme Levi Tres, Olindo Assis Martins-Filho, Vanessa Peruhype-Magalhães, Valéria Valim, Gilda Aparecida Ferreira, Andréa Teixeira-Carvalho, Edgard Torres dos Reis-Neto, Emilia Inoue Sato, Marcelo de Medeiros Pinheiro, Viviane Angelina de Souza, Ricardo Machado Xavier, Gecilmara Salviato Pileggi and Odirlei André Monticielo Show full author list Hide full author list

Vaccines 2025, 13(10), 1074; https://doi.org/10.3390/vaccines13101074 - 21 Oct 2025

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Abstract

Background: To prospectively evaluate the safety and clinical impact of SARS-CoV-2 vaccines in patients with systemic lupus erythematosus (SLE). Methods: Subanalysis of the Brazilian multicenter observational study “Safety, Effectiveness and Duration of Immunity after Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Inflammatory Diseases [...] Read more.

Background: To prospectively evaluate the safety and clinical impact of SARS-CoV-2 vaccines in patients with systemic lupus erythematosus (SLE). Methods: Subanalysis of the Brazilian multicenter observational study “Safety, Effectiveness and Duration of Immunity after Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Inflammatory Diseases (SAFER)”, which included SLE patients vaccinated with CoronaVac, ChAdOx1, or BNT162b2. Patients with HIV infection, pregnant women, or those with immunosuppression not related to SLE were excluded. Safety data related to adverse events and underlying disease activity were assessed. Additionally, COVID-19 cases were monitored throughout the follow-up period. Results: The study included 373 patients with systemic lupus erythematosus (SLE), with a mean age of 36 years, the majority being women (89.8%). The most common adverse events after SARS-CoV-2 vaccination were injection site reactions and headache, observed both after the first and subsequent doses. The ChAdOx-1 vaccine was associated with a higher frequency of adverse events compared to CoronaVac. At baseline, 38.3% of patients were in remission, 32.8% had low disease activity, and 28.9% had moderate to high activity. Following CoronaVac vaccination, there was an increase in remission rates (from 34.6% to 51.1%) and a significant reduction in moderate to high activity (from 37.6% to 15.0%) after the first dose, with this reduction partially maintained after the second dose. In contrast, patients vaccinated with ChAdOx-1 showed an increase in moderate to high activity (from 14.5% to 38.2% after the first dose), a trend that persisted after the second dose. No statistically significant changes in disease activity were observed among those who received BNT162b2. During follow-up, 44 cases of COVID-19 were reported, all mild, with no deaths or need for intensive care unit admission. Conclusions: Vaccination against SARS-CoV-2 demonstrated a favorable safety profile in patients with SLE, with a low frequency of serious adverse events. While analysis of disease activity revealed variations across vaccine platforms, most notably an increased proportion of moderate to high disease activity among those receiving ChAdOx-1 compared with CoronaVac and BNT162b2, the overall occurrence of COVID-19 during follow-up was limited to mild cases, with no severe outcomes. These findings highlight that, despite potential risks of disease exacerbation, the clear protection against severe COVID-19 supports vaccination as a beneficial strategy for this immunocompromised population. Full article

(This article belongs to the Section COVID-19 Vaccines and Vaccination)

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13 pages, 732 KB

Open AccessReview

Vaccination Against Herpes Zoster in Adults: Current Strategies in European Union Countries

by Manuela Chiavarini, Angela Bechini, Sara Boccalini, Alisa Barash, Enrica Castellana, Alessandro Senape and Paolo Bonanni

Vaccines 2025, 13(10), 1073; https://doi.org/10.3390/vaccines13101073 - 20 Oct 2025

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Abstract

Background/Objectives: Herpes zoster (HZ), caused by varicella zoster virus (VZV) reactivation, significantly affects the functional status and quality of life of older adults and immunocompromised individuals. Vaccination represents an effective strategy to reduce the incidence of HZ. Methods: This review offers a cross-sectional [...] Read more.

Background/Objectives: Herpes zoster (HZ), caused by varicella zoster virus (VZV) reactivation, significantly affects the functional status and quality of life of older adults and immunocompromised individuals. Vaccination represents an effective strategy to reduce the incidence of HZ. Methods: This review offers a cross-sectional assessment of the current landscape of adult herpes zoster vaccination strategies across the 27 EU member states, drawing on data available up to July 2025 from official sources such as the ECDC, the WHO, and national health authorities. Results: HZ vaccination is recommended in 17 EU countries (63%) according to the National Immunization Programs (NIPs) or by other institutional national health documents; in only 7 countries, vaccination is fully covered by the national healthcare system. HZ vaccination is recommended for healthy adults aged ≥50 years in 23.5% of countries (4/17), ≥60 years in 29.4% (5/17), and ≥65 years in 41.2% (7/17). At-risk groups are targeted in 94.1% of countries (16/17), predominantly from age 18 years (14 countries). Conclusions: An overall tendency toward broader HZ vaccination strategies, targeting both older adults and risk groups, is emerging. However, differences among national policies, together with the European Commission’s withdrawal of the live-attenuated Zostavax vaccine effective 1 June 2025, highlight the urgent need for comprehensive, harmonized immunization strategies to ensure adequate coverage of adult HZ vaccination across Europe. Full article

(This article belongs to the Special Issue From Knowledge to Action: Advances in Herpes Zoster Vaccine and Vaccination)

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16 pages, 2728 KB

Open AccessArticle

Efficacy Evaluation of an E2 Subunit Vaccine Against Highly Virulent Classical Swine Fever Virus Strain

by Yu-Chieh Chen, Chi-Chih Chen, Wen-Bin Chung, Yen-Li Huang, Guan-Ming Ke and Hso-Chi Chaung

Vaccines 2025, 13(10), 1072; https://doi.org/10.3390/vaccines13101072 - 20 Oct 2025

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Abstract

Background/Objectives: Classical swine fever (CSF) is listed by the World Organisation for Animal Health as a highly devastating and contagious pig disease, causing severe economic losses to the swine industry. In spite of the successful elimination of CSF in Taiwan, preparedness against [...] Read more.

Background/Objectives: Classical swine fever (CSF) is listed by the World Organisation for Animal Health as a highly devastating and contagious pig disease, causing severe economic losses to the swine industry. In spite of the successful elimination of CSF in Taiwan, preparedness against potential reintroduction remains essential. The live attenuated vaccines have been effective in disease control, but are not capable of a viable strategy that differentiates infected from vaccinated animals (DIVA). Subunit vaccines are recognized for their safety and ability to induce protective immunity against infectious diseases. Methods: In this study, the recombinant CSF virus (CSFV) E2 proteins were formulated with a CpG motif as an adjuvant to produce the E2-CpG subunit vaccine. Its efficiency in specific-pathogen-free (SPF) pigs was compared with a commercially available E2 subunit vaccine (Bayovac^® CSF-E2; Bayer Taiwan Co., Ltd., Taipei City, Taiwan). Results: Significantly higher titers of anti-E2 antibodies were induced in pigs immunized with a single dose of the E2-CpG vaccine, particularly the reduced E-0.5A formulation, than those immunized with a dose of the commercialized E2 subunit vaccine adjusted to double dosage. This designed subunit vaccine showed high efficacy in protection against clinical symptoms and significant pathological alterations in pigs after a highly virulent CSFV (genotype 1.1) challenge. Viral shedding was not detected in vaccinated pigs before completion of the challenge study, and the viral load in their spleens remained undetectable. Conclusions: These results could support the potential of the E2-CpG vaccine as a cost-effective, single-dose subunit vaccine capable of inducing robust CSFV-specific immunity and providing 100% protection against lethal CSFV challenges. Full article

(This article belongs to the Special Issue Swine Vaccines and Vaccination)

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15 pages, 2603 KB

Open AccessReview

Global Transmission, Prevention, Control, and Treatment of Mpox Virus in 2025: A Comprehensive Review from Infection Mechanisms to Vaccine Development

by Quan Quan, Nan Wu, Ying-Hua Luo, Yan-Jun Tang, Yan-Zhi Liu, Xi-Chun Huang, Jun-Hao Li, Wan-Xia Ren and Cheng-Hao Jin

Vaccines 2025, 13(10), 1071; https://doi.org/10.3390/vaccines13101071 - 20 Oct 2025

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Abstract

The World Health Organization (WHO) declared the mpox (MPX) outbreak a public health emergency of international concern (PHEIC) on 23 July 2022, and 14 August 2024, respectively, underscoring the confirmed and concerning global spread of the disease. A gap exists in our fundamental [...] Read more.

The World Health Organization (WHO) declared the mpox (MPX) outbreak a public health emergency of international concern (PHEIC) on 23 July 2022, and 14 August 2024, respectively, underscoring the confirmed and concerning global spread of the disease. A gap exists in our fundamental understanding of the mpox virus (MPXV), despite its genetic relatedness to the variola virus (VARV). This knowledge deficit is evident in the performance of current medical countermeasures; vaccines and antiviral therapies adapted from smallpox programs demonstrate only partial efficacy and are constrained by issues of safety and suboptimal effectiveness against MPXV. In this context, the development of MPX-specific vaccines and antiviral drugs has become a critical priority in the global effort to combat MPX. However, MPXV employs multiple strategies to evade host immune responses, such as producing specific and poxvirus homologous proteins that suppress both innate immunity (including the six principal innate immune signaling pathways and antiviral strategies, notably the interferon [IFN] pathway) and adaptive immunity, thereby complicating vaccine and drug development. Insights from research on vaccinia virus (VACV) and VARV may inform the investigation of MPXV pathogenesis and immune evasion mechanisms. Drawing on relevant scientific literature, this review systematically examines key aspects of MPX infection, pathogenicity, and immune evasion, as well as the coordination between innate and adaptive immune responses. Furthermore, this review elucidates the current application and deployment landscape of the three principal therapeutics and three major vaccines for MPX, aiming to provide a theoretical foundation for future research and development of vaccines and targeted antiviral agents. Full article

(This article belongs to the Section Vaccines and Public Health)

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34 pages, 7924 KB

Open AccessSystematic Review

Efficacy, Safety and Predictive Biomarkers of Oncolytic Virus Therapy in Solid Tumors: A Systematic Review and Meta-Analysis

by Mohamed El-Tanani, Syed Arman Rabbani, Mohamed Anas Patni, Rasha Babiker, Shakta Mani Satyam, Imran Rashid Rangraze, Adil Farooq Wali, Yahia El-Tanani and Thantrira Porntaveetus

Vaccines 2025, 13(10), 1070; https://doi.org/10.3390/vaccines13101070 - 20 Oct 2025

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Abstract

Background: Oncolytic virus (OV) therapy couples direct tumor lysis with systemic immune priming, yet clinical benefit remains heterogeneous and the predictive biomarker landscape is poorly defined. We undertook a systematic review and meta-analysis to quantify the efficacy and safety of OV therapy in [...] Read more.

Background: Oncolytic virus (OV) therapy couples direct tumor lysis with systemic immune priming, yet clinical benefit remains heterogeneous and the predictive biomarker landscape is poorly defined. We undertook a systematic review and meta-analysis to quantify the efficacy and safety of OV therapy in solid tumors and to synthesize current evidence on response-modulating biomarkers. Methods: Following PRISMA 2020 guidelines, MEDLINE, Embase, Cochrane CENTRAL, ProQuest and Scopus were searched from inception to May 2025. Phase II–III randomized trials of genetically engineered or naturally occurring OV reporting objective response rate (ORR), progression-free survival (PFS), overall survival (OS) or biomarker data were eligible. Hazard ratios (HRs) or odds ratios (OR) were pooled with random-effects models; heterogeneity was assessed with I² statistics. Qualitative synthesis integrated genomic, immunologic and microbiome biomarkers. Results: Thirty-six trials encompassing around 4190 patients across different tumor types met inclusion criteria. Compared with standard therapy, OV-based regimens significantly improved ORR nearly three-fold (pooled OR = 2.77, 95% CI 1.85–4.16), prolonged PFS by 11% (HR = 0.89, 95% CI 0.80–0.99) and reduced mortality by 16% (OS HR = 0.84, 95% CI 0.72–0.97; I² = 59%). Benefits were most pronounced in melanoma (ORR 26–49%; OS HR 0.57–0.79) and in high-dose vaccinia virus for hepatocellular carcinoma (HR = 0.39). Grade ≥ 3 adverse events were not increased versus control (risk ratio 1.05, 95% CI 0.89–1.24); common toxicities were transient flu-like symptoms and injection-site reactions. Biomarker synthesis revealed that high tumor mutational burden, interferon-pathway loss-of-function mutations, baseline CD8⁺ T-cell infiltration, post-OV upregulation of IFN-γ/PD-L1, and favorable gut microbial signatures correlated with response, whereas intact antiviral signaling, immune-excluded microenvironments and myeloid dominance predicted resistance. Conclusions: OV therapy confers clinically meaningful improvements in tumor response, PFS and OS with a favorable safety profile. Integrating composite genomic–immune–microbiome biomarkers into trial design is critical to refine patient selection and realize precision viro-immunotherapy. Future research should prioritize biomarker-enriched, rational combination strategies to overcome resistance and extend benefit beyond melanoma. Full article

(This article belongs to the Special Issue Cancer Vaccines and Immunotherapy: Latest Advances, Limitations and Prospects)

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11 pages, 338 KB

Open AccessArticle

Demographic and Clinical Characteristics of Patients Vaccinated Against Herpes Zoster in a Primary Care Setting in Spain: A Retrospective Study

by José María Blanc-Rodriguez-Arias, Isabel Jimeno-Sanz, Valentín Hernández-Barrera, Alejandro Álvaro-Meca, Manuel Torres-Ramos and Ángel Gil-de-Miguel

Vaccines 2025, 13(10), 1069; https://doi.org/10.3390/vaccines13101069 - 20 Oct 2025

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Abstract

Background: Herpes zoster (HZ), commonly known as shingles, is a reactivation of the varicella-zoster virus that predominantly affects older adults and immunocompromised individuals. Vaccination with the recombinant zoster vaccine (RZV) has proven effective in preventing HZ and its complications in real-world scenarios, yet [...] Read more.

Background: Herpes zoster (HZ), commonly known as shingles, is a reactivation of the varicella-zoster virus that predominantly affects older adults and immunocompromised individuals. Vaccination with the recombinant zoster vaccine (RZV) has proven effective in preventing HZ and its complications in real-world scenarios, yet coverage remains suboptimal in primary care settings. This study aims to analyse the demographic and clinical characteristics of HZ-vaccinated patients in a primary care centre in Madrid, Spain, in 2023 and to assess adherence to the vaccination schedule. Methods: A retrospective descriptive analysis was conducted, including 1146 patients from a single primary care centre who received at least one dose of RZV during the study period. Data were extracted from medical records. Patient characteristics, including age, sex, and the presence of comorbidities (e.g., diabetes, chronic obstructive pulmonary disease, hypertension, asthma), were examined. Vaccine coverage was calculated for the new age cohorts introduced in the year 2023. Comorbidity prevalence was also analysed by age and sex to determine patterns in vaccination uptake. Results: The analysis revealed that 66% of vaccinated individuals presented one or more of the analysed comorbidities. Adherence to the two-dose schedule was 91.97%, and vaccine coverages were 46.56% in those born between 1943–1948 and 39.32% in the 1958 cohort. The findings underscore the need for targeted strategies to raise disease awareness and improve HZ vaccination rates and adherence, particularly among elderly individuals and those with comorbid conditions. Conclusions: This study specifies the clinical characteristics of HZ-vaccinated patients in a primary care setting and highlights the importance of enhanced vaccination awareness and adherence strategies to reduce the burden of HZ among at-risk populations. Full article

(This article belongs to the Section Vaccines and Public Health)

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4 pages, 162 KB

Open AccessEditorial

Vaccine Development for Influenza Virus

by Ganesh Yadagiri and Mingtao Zeng

Vaccines 2025, 13(10), 1068; https://doi.org/10.3390/vaccines13101068 - 19 Oct 2025

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Abstract

Influenza is a contagious respiratory viral infection that remains a persistent global public-health threat responsible for three to five million severe illnesses and 290,000 to 650,000 respiratory deaths annually [...] Full article

(This article belongs to the Special Issue Vaccine Development for Influenza Virus)

13 pages, 699 KB

Open AccessArticle

Seroprevalence of Poliovirus Types 1, 2, and 3 Among Children Aged 6–11 Months: Variations Across Survey Rounds in High-Risk Areas of Pakistan

by Imtiaz Hussain, Ahmad Khan, Muhammad Umer, Muhammad Sajid, Haider Abbas, Muhammad Masroor Alam, Altaf Bosan, Jeffrey Partridge, Rehan Hafiz, Anwar-ul Haq and Sajid Soofi

Vaccines 2025, 13(10), 1067; https://doi.org/10.3390/vaccines13101067 - 19 Oct 2025

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Abstract

Background: The current polio epidemiology in Pakistan poses a unique challenge for global eradication, with polio transmission dynamics influenced by regional variations in immunity and disparities in immunization coverage. This study assesses the immunity level for all three poliovirus types among children [...] Read more.

Background: The current polio epidemiology in Pakistan poses a unique challenge for global eradication, with polio transmission dynamics influenced by regional variations in immunity and disparities in immunization coverage. This study assesses the immunity level for all three poliovirus types among children aged 6–11 months in polio high-risk regions of Pakistan. Methods: Four consecutive rounds of cross-sectional serological surveys were conducted in polio high-risk areas of Pakistan between November 2016 and October 2023. Twelve high-risk areas were covered in the first three rounds of the survey, while 44 high-risk areas were covered in the fourth round. 25 clusters from each geographical stratum were selected utilizing probability proportional to size. Results: Across the four rounds of the survey, 32,907 children aged 6–11 months from 2084 clusters and 32,371 households were covered. Comparative analysis across the survey rounds showed that seroprevalence of poliovirus type 1 was high in provinces (>95%), albeit consistently lower in Balochistan (going down to 89.7% in Round 4). Type 2 seroprevalence was significantly lower and more heterogeneous, from 34.6% in Sindh to 83.4% in Punjab, with sharp declines by round 4, particularly in Balochistan (40.4%). Type 3 seroprevalence was overall high (>94% in Punjab, Sindh, and KPK) but dropped in the last round, while Balochistan exhibited continually lower immunity (81.1%). Conclusions: The findings reflect the variations in population immunity to poliovirus in the country, with notable fluctuations over the years. The gaps in type 2 immunity over time and consistently lowest in Balochistan highlight the need for continued monitoring of immunity levels and adaptable vaccination strategies. Full article

(This article belongs to the Section Epidemiology and Vaccination)

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12 pages, 2336 KB

Open AccessArticle

Epidemiological Survey of Porcine Circovirus Type 2 (PCV2) in Large-Scale Pig Farms in Hubei Province and Comprehensive Evaluation of Commercial Vaccine Efficacy

by Wenjun Liao, Zhaofang Xi, Rui Fang, Bang Shen and Junlong Zhao

Vaccines 2025, 13(10), 1066; https://doi.org/10.3390/vaccines13101066 - 18 Oct 2025

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Abstract

Background: Porcine circovirus type 2 (PCV2) is the primary pathogen responsible for postweaning multisystemic wasting syndrome (PMWS) and related diseases, leading to significant economic losses in the global pig industry. Methods: This study conducted a thorough epidemiological survey between 2022 and 2024, gathering [...] Read more.

Background: Porcine circovirus type 2 (PCV2) is the primary pathogen responsible for postweaning multisystemic wasting syndrome (PMWS) and related diseases, leading to significant economic losses in the global pig industry. Methods: This study conducted a thorough epidemiological survey between 2022 and 2024, gathering 6600 samples from 24 large-scale pig farms in Hubei Province. On the basis of these findings, the immune response and economic benefits of two representative commercial PCV2 subunit vaccines, recombinant baculovirus CP08 and Ingelvac CircoFLEX^®, were assessed in a modern fattening farm in Xiangyang city. Results: The results indicated no detection of viral antigens in sows; however, weaned piglets and fattening pigs presented high positivity rates, with 8-week-old nursery pigs identified as the peak period for infection. Both vaccines significantly improved average weight gain and reduced antigen positivity, with Ingelvac CircoFLEX^® demonstrating superior viral control and economic returns. Conclusions: This study offers valuable scientific and practical guidance for PCV2 control strategies and vaccine selection in Hubei and comparable regions. Full article

(This article belongs to the Section Veterinary Vaccines)

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20 pages, 1181 KB

Open AccessArticle

The Potential Public Health Impact of the mRNA-Based Respiratory Syncytial Virus Vaccine, mRNA-1345, Under Extended Vaccination Campaigns Among Older Adults in the United Kingdom: A Modelling Study

by Mariia Dronova, Anna Tytuła, Zuzanna Janusz, Parinaz Ghaswalla, Stuart Carroll, Orsolya Balogh and Keya Joshi

Vaccines 2025, 13(10), 1065; https://doi.org/10.3390/vaccines13101065 - 18 Oct 2025

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Abstract

Background/Objectives: Respiratory syncytial virus (RSV) is a leading cause of severe respiratory disease in older adults. Despite growing recognition of RSV as a public health concern, vaccination options remain limited. This study assessed the potential long-term public health impact of extended mRNA-1345 [...] Read more.

Background/Objectives: Respiratory syncytial virus (RSV) is a leading cause of severe respiratory disease in older adults. Despite growing recognition of RSV as a public health concern, vaccination options remain limited. This study assessed the potential long-term public health impact of extended mRNA-1345 RSV vaccination campaigns. Methods: A dynamic transmission model, stratified by age, was developed to evaluate the epidemiological and clinical impact of RSV vaccination in the UK over a 20-year time horizon. Eight vaccination strategies were assessed: two reflecting the JCVI recommendation for the 2024–2025 season and its recent extension, and six extended strategies considering broader eligible age groups, higher coverage, and/or revaccination every 2 or 3 years. Two exploratory analyses and extensive model validation versus reported data were also conducted. Results: Strategies combining broader age eligibility (≥60 years), higher coverage (80%), and 2-year revaccination achieved the greatest impact, preventing 310,000 hospitalisations over 20 years in the total UK population. Exploratory analyses showed that the expected public health impact might exceed the estimates presented in this analysis, if an alternative vaccine efficacy profile or the projected demographic shift would be confirmed. Conclusions: Extended RSV vaccination strategies including broader age eligibility and routine revaccination could offer substantial public health benefits in the UK. Targeting adults aged ≥60 years is expected to be particularly efficient in achieving a sustainable reduction in RSV burden. These findings could provide valuable support for national policy discussions on optimising RSV vaccination strategies in older adults, particularly regarding target age groups, revaccination schedules, and long-term programme planning. Full article

(This article belongs to the Special Issue Respiratory Syncytial Virus (RSV) Vaccine)

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30 pages, 2907 KB

Open AccessSystematic Review

Health System Determinants of Delivery and Uptake of HPV Vaccination Services Among Involuntary Migrant Populations: A Qualitative Systematic Review

by Jennifer Nyawira Githaiga, Jill Olivier, Susanne Noll and Edina Amponsah-Dacosta

Vaccines 2025, 13(10), 1064; https://doi.org/10.3390/vaccines13101064 - 18 Oct 2025

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Abstract

Background: Migrant populations are commonly under-immunised relative to general populations in host countries. The evidence base on routine vaccination among migrant children suggests that higher priority is given to infants and younger children compared to adolescents. Though migrants are often classified as a [...] Read more.

Background: Migrant populations are commonly under-immunised relative to general populations in host countries. The evidence base on routine vaccination among migrant children suggests that higher priority is given to infants and younger children compared to adolescents. Though migrants are often classified as a homogenous group, different sub-populations of migrants exist, including voluntary migrants who choose to move and involuntary migrants forcibly displaced by humanitarian crises. The human papillomavirus (HPV) vaccine, a relatively recent addition to global routine immunisation schedules for adolescents, is a useful proxy for understanding vaccine equity for this under-prioritised group. This qualitative systematic review explores health system determinants of delivery and uptake of HPV vaccination services among involuntary migrants. Methods: A literature search was conducted across ten electronic databases. An analytical framework tailored to the migrant context aided in capturing the complexity and magnitude of systemic factors that determine vaccine delivery and uptake among involuntary migrants. Of the 676 records retrieved, 27 studies were included in this review. Results: Key determinants of vaccine delivery include adaptation of immunisation policies for migrant inclusiveness, implementation of migrant-targeted interventions, health provider recommendations, electronic health records, and free vaccines. Uptake determinants include access dependent on legal status, awareness-related determinants akin to culturally appropriate health messaging, and acceptance-related determinants associated with sociocultural beliefs, misinformation, and distrust. Conclusions: Prioritising vaccination programmes linked with non-outbreak-related diseases is challenging in the disruptive context of humanitarian crises given fragile health systems, limited resources, loss of health infrastructure and deployment of health personnel to emergency care. We strongly advocate for global actors at all health systems levels to actively reform national HPV vaccination programmes to enhance inclusivity of adolescent girls in crises settings or resettled in host countries. Full article

(This article belongs to the Special Issue Inequality in Immunization 2025)

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15 pages, 1103 KB

Open AccessArticle

A Novel Flow Cytometry Array for High Throughput Detection of SARS-CoV-2 Antibodies

by Benyue Zhang, Zhuo Zhang, Yichao Zhao, Jingqiao Lu, Jianmin Fang, Brianne Petritis, Kelly Whittaker, Rani Huang and Ruo-Pan Huang

Vaccines 2025, 13(10), 1063; https://doi.org/10.3390/vaccines13101063 - 17 Oct 2025

Viewed by 427

Abstract

Background/Objectives: Although the U.S. Food and Drug Administration (FDA) has approved one antiviral treatment and authorized others for emergency use, there is no fully effective antiviral therapy for coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 [...] Read more.

Background/Objectives: Although the U.S. Food and Drug Administration (FDA) has approved one antiviral treatment and authorized others for emergency use, there is no fully effective antiviral therapy for coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Assays detecting virus-specific immunoglobulins (Ig) or nucleic acids in large-scale epidemiological, vaccine, and drug development studies remain limited due to high costs, reagent accessibility, and cumbersome protocols. Methods: A multiplex bead-based assay was developed to simultaneously detect human IgM, IgG, and IgA antibodies against the SARS-CoV-2 spike receptor binding domain (RBD) in serum using flow cytometry. Assay performance was evaluated for sensitivity, specificity, reproducibility, and cross-reactivity and compared to another immunoassay platform. Results: The assay enabled simultaneous measurement of three antibody isotypes across 624 samples within 2 h. Intra-plate coefficients of variation (CVs) ranged from 3.16 to 6.71%, and inter-plate CVs ranged from 3.33 to 5.49%, demonstrating high reproducibility. The platform also quantified background noise from nonspecific binding, facilitating straightforward data interpretation. Conclusions: This novel, flexible multiplex bead-based assay utilizing a well-established platform provides a rapid and reproducible approach for detecting SARS-CoV-2-specific antibodies. Its high throughput capacity and low variability make it well suited for large-scale epidemiological, vaccine, and therapeutic studies. The platform’s adaptability further supports application to other infectious diseases, offering an ideal tool for broad immunological surveillance. Full article

(This article belongs to the Special Issue COVID Vaccines: Design, Development, and Immune Response Studies: 2nd Edition)

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16 pages, 2008 KB

Open AccessArticle

Optimization of In Vitro Transcription by Design of Experiment to Achieve High Self-Amplifying RNA Integrity

by Chaoying Hu, Haixin Wang, Guanxing Liu, Kelei Li, Xuanxuan Zhang, Lifang Song, Fan Gao, Xing Wu, Qian Wang, Mingchen Liu, Jianyang Liu, Zhihao Fu, Xiao Ma, Miao Xu, Qunying Mao, Zhenglun Liang and Qian He

Vaccines 2025, 13(10), 1062; https://doi.org/10.3390/vaccines13101062 - 17 Oct 2025

Viewed by 446

Abstract

Background: Self-amplifying mRNA (saRNA) holds promising application prospects. However, due to the inclusion of a replicase sequence, its extended length leads to premature termination during in vitro transcription (IVT), resulting in poor product integrity. This study aims to optimize the IVT process for [...] Read more.

Background: Self-amplifying mRNA (saRNA) holds promising application prospects. However, due to the inclusion of a replicase sequence, its extended length leads to premature termination during in vitro transcription (IVT), resulting in poor product integrity. This study aims to optimize the IVT process for saRNA vaccines to enhance integrity, thereby addressing the key challenge in saRNA vaccine manufacturing. Method: Guided by the Quality by Design (QbD) framework, Design of Experiment (DoE) methodology was employed to design diverse combinations of process parameters for IVT reactions. Predictive models were established to identify critical process parameters (CPPs) influencing integrity and yield. An optimized parameter set and process design space, meeting predefined yield and integrity standards, were developed. The impact of integrity on the immunogenicity of saRNA vaccines was further investigated. Results: Mg²⁺ concentration exerted the most pronounced effect on saRNA integrity. Under optimized IVT conditions, integrity exceeded 85%. Mathematical modeling simulations defined the IVT design space, meeting the preset criteria of ≥80% integrity and ≥600 μg/100 μL yield while accommodating longer saRNA constructs. Notably, murine model data revealed that higher saRNA integrity significantly enhanced antigen-specific antibody and T-cell responses. Conclusion: This study successfully established a multivariate IVT design space fulfilling preset integrity and yield criteria, providing critical data references for the industrialization and quality specification development of saRNA vaccines. Full article

(This article belongs to the Section Nucleic Acid (DNA and mRNA) Vaccines)

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13 pages, 1515 KB

Open AccessArticle

Neutralisation of the Immunoglobulin-Cleaving Activity of Streptococcus equi Subspecies equi IdeE by Blood Sera from Ponies Vaccinated with a Multicomponent Protein Vaccine

by Francesco Righetti, Karina Hentrich, Margareta Flock, Sara Frosth, Karin Jacobsson, Joakim Bjerketorp, Anuj Pathak, Noela Ido, Birgitta Henriques-Normark, Lars Frykberg, Romain Paillot, Bengt Guss, Tim Wood, Jan-Ingmar Flock and Andrew Stephen Waller

Vaccines 2025, 13(10), 1061; https://doi.org/10.3390/vaccines13101061 - 17 Oct 2025

Viewed by 350

Abstract

Background: Streptococcus equi subspecies equi (S. equi) is the cause of strangles, one of the most prevalent diseases of horses worldwide. The disease is characterised by fever and the formation of abscesses in the lymph nodes of the head and [...] Read more.

Background: Streptococcus equi subspecies equi (S. equi) is the cause of strangles, one of the most prevalent diseases of horses worldwide. The disease is characterised by fever and the formation of abscesses in the lymph nodes of the head and neck, which can restrict the airway. A multicomponent subunit vaccine, Strangvac, has been shown to effectively reduce clinical signs of strangles and to reduce its incidence. Objective: The aim of this study was to determine the immune response against the immunoglobulin-cleaving endopeptidase IdeE, a key protective component within the vaccine and the ability of antibodies to neutralize the proteolytic activity of IdeE. Methods: An in vitro assay was developed to measure the functional inhibition of recombinant IdeE by horse sera pre- and post-vaccination. The IdeE-neutralising titres were compared to the corresponding IdeE-specific antibody titres measured by iELISA (indirect Enzyme-Linked Immunosorbent Assay). Results: A significant IdeE-specific antibody response in blood serum collected from ponies was induced after Strangvac vaccinations. Concomitantly, significant increases in the neutralising activity of IdeE occurred, persisting for at least 12 months post-second vaccination. IdeE-neutralising activity was further increased significantly after a third vaccination, even when the third dose was administered 12 months after the second dose, demonstrating that immunological memory to the vaccine persisted for 12 months. There was a significant correlation between the IdeE-neutralising activity of blood sera and the level of IdeE-specific antibodies. Conclusions: These data provide insights into one potential mechanism by which this vaccine protects Equids against or during S. equi infection. Full article

(This article belongs to the Special Issue Animal Diseases: Immune Response and Vaccines)

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34 pages, 2916 KB

Open AccessReview

Impediments to Progress Toward Polio Eradication During 2014–2024: Effectively Addressing the Current Challenges

by Steven G. F. Wassilak, Abdinoor Mohamed and John Paul Bigouette

Vaccines 2025, 13(10), 1060; https://doi.org/10.3390/vaccines13101060 - 17 Oct 2025

Viewed by 479

Abstract

When the Global Polio Eradication Initiative (GPEI) began in 1988, the year 2000 target was clearly ambitious. Nonetheless, among 20 countries with endemic wild poliovirus transmission in 2000, only Afghanistan, Nigeria and Pakistan remained endemic in 2014; successful global eradication was anticipated within [...] Read more.

When the Global Polio Eradication Initiative (GPEI) began in 1988, the year 2000 target was clearly ambitious. Nonetheless, among 20 countries with endemic wild poliovirus transmission in 2000, only Afghanistan, Nigeria and Pakistan remained endemic in 2014; successful global eradication was anticipated within years. Transmission was interrupted in Nigeria after implementing innovative activities; unfortunately, transmission in Afghanistan and Pakistan has continued into 2025. An additional challenge has been controlling outbreaks and interrupting persistent transmission of circulating vaccine-derived poliovirus type 2 detected after global withdrawal of the use of Sabin strain type 2 oral poliovirus vaccine. The impediments to progress since 2014 are detailed and the challenges that the GPEI must successfully mitigate are reviewed herein. Primary challenges since the acute phase of the COVID-19 pandemic include the loss of a sense of urgency and political will/national ownership in stopping poliovirus transmission, lower childhood routine immunization coverage and the decreased quality of outbreak response campaigns. These facets need to be strengthened. Ongoing security challenges require continued vigilance in affected areas of wild poliovirus-endemic countries as well as in countries with persistent transmission of vaccine-derived poliovirus. Eradication can be achieved if the multiple challenges mentioned are urgently and more effectively mitigated. Decreased funding for the GPEI in 2025 represents the primary, acute challenge that, if not urgently addressed, may allow for the reversal of all progress to date. Full article

(This article belongs to the Special Issue Vaccination Strategies for Global Public Health)

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19 pages, 320 KB

Open AccessReview

Gender Barriers to Immunization: A Synthesis of UNICEF’s Analyses to Advance Equity and Coverage

by Cristián Mansilla, Alinane Kamlongera and Ibrahim Dadari

Vaccines 2025, 13(10), 1059; https://doi.org/10.3390/vaccines13101059 - 16 Oct 2025

Viewed by 510

Abstract

Background/objectives: Despite global efforts to improve childhood immunization rates, gender-related barriers continue to hinder equitable access to vaccines worldwide. This study synthesizes gender barrier analyses conducted in various countries to better understand these challenges. This evidence synthesis aims to (1) identify the main [...] Read more.

Background/objectives: Despite global efforts to improve childhood immunization rates, gender-related barriers continue to hinder equitable access to vaccines worldwide. This study synthesizes gender barrier analyses conducted in various countries to better understand these challenges. This evidence synthesis aims to (1) identify the main gender-related barriers affecting immunization focusing on zero-dose targets, HPV, and COVID-19 vaccination campaigns; and (2) summarize key recommendations and lessons that have emerged from countries to overcome those gender barriers. Methods: A documentary analysis was used by reviewing data from gender barrier analyses that were conducted by multiple governments with UNICEF support. The study classified barriers using the socio-ecological model (SEM), encompassing systemic, health service, community, household, and individual-level gender barriers. Descriptive statistics and inductive thematic coding were used to analyze data. Results: This synthesis includes 24 documents representing gender barrier analyses across 29 countries. Findings highlight multiple barriers, including systemic discrimination against women in public and healthcare spaces, limited political will to address gender disparities, and limited (sex)-disaggregated and gender data. At the community and household levels, social norms restrict women’s autonomy in seeking immunization services, while household duties (culturally assigned to women) also restrict their access to immunization services. Adolescents face additional challenges, particularly regarding HPV vaccination, due to misconceptions and stigma from families and peers. Conclusions: Addressing gender-related barriers requires a multi-level approach, integrating gender-responsive policies, and comprehensively addressing gender barriers that are hindering the progress of vaccination efforts. UNICEF’s commitment to gender-responsive immunization strategies is critical for achieving the Immunization Agenda 2030 and ensuring equitable vaccine access for all. Full article

(This article belongs to the Special Issue Inequality in Immunization 2025)

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15 pages, 820 KB

Open AccessArticle

Maternal Cigarette Smoke Exposure Does Not Impair Influenza Vaccine Responsiveness in Murine Offspring

by Ali Dehghani, Johan Garssen, Ingrid van Ark, Gert Folkerts, Jeroen van Bergenhenegouwen and Saskia Braber

Vaccines 2025, 13(10), 1058; https://doi.org/10.3390/vaccines13101058 - 16 Oct 2025

Viewed by 378

Abstract

Background/Objectives: Environmental pollutants can profoundly affect immune development, yet their impact on offspring vaccine responsiveness remains poorly understood. To address this, we investigated the impact of maternal cigarette smoke (CS) exposure, a major contributor to household air pollution, on influenza vaccine responsiveness in [...] Read more.

Background/Objectives: Environmental pollutants can profoundly affect immune development, yet their impact on offspring vaccine responsiveness remains poorly understood. To address this, we investigated the impact of maternal cigarette smoke (CS) exposure, a major contributor to household air pollution, on influenza vaccine responsiveness in offspring. Methods: Pregnant dams were exposed to CS or air during gestation and lactation. Two weeks post-weaning, offspring received two influenza vaccinations. After the booster vaccination, vaccine-specific delayed-type hypersensitivity (DTH), serum immunoglobulins, and splenic T cells were analyzed. Results: Vaccinated offspring exhibited robust DTH responses and comparable levels of vaccine-specific IgG1 and IgG2a, regardless of maternal exposure. Importantly, maternal CS exposure did not affect splenic Th1 cell frequency in vaccinated offspring but increased the frequency of activated Th2 cells. Conclusions: In conclusion, immune development was affected by enhanced Th2 activation, but vaccine efficacy was not impaired. These findings suggest that, under the current conditions of CS exposure (duration, route, and timing) and influenza vaccine dose, vaccine-induced immunity may exhibit resilience even in the presence of environmental immune modulators such as maternal CS exposure. However, these unexpected results highlight the need for further investigation into the broader health implications of maternal pollutant exposure, particularly considering how exposure timing, type, and route, as well as vaccine characteristics, may influence immune development and responsiveness. A deeper understanding of these factors is essential to fully elucidating the clinical relevance of maternal pollutant exposure on childhood vaccine efficacy. Full article

(This article belongs to the Special Issue Effectiveness and Safety of Vaccines in Special Populations)

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16 pages, 10159 KB

Open AccessArticle

Design and Evaluation of a Broadly Multivalent Adhesins-Based Multi-Epitope Fusion Antigen Vaccine Against Enterotoxigenic Escherichia coli Infection

by Yanyan Jia, Ke Yang, Qijuan Sun, Weiqi Guo, Zhihao Yang, Zihan Duan, Shiqu Zhang, Rongxian Guo, Ke Ding, Chengshui Liao and Shaohui Wang

Vaccines 2025, 13(10), 1057; https://doi.org/10.3390/vaccines13101057 - 16 Oct 2025

Viewed by 304

Abstract

Background: Enterotoxigenic Escherichia coli (ETEC) is a zoonotic pathogen causing diarrhea and mortality in infants and livestock. Its numerous serotypes necessitate the urgent development of multivalent vaccines for effective prevention, thereby reducing public health and economic threats. Methods: Computational bioinformatics analyses [...] Read more.

Background: Enterotoxigenic Escherichia coli (ETEC) is a zoonotic pathogen causing diarrhea and mortality in infants and livestock. Its numerous serotypes necessitate the urgent development of multivalent vaccines for effective prevention, thereby reducing public health and economic threats. Methods: Computational bioinformatics analyses were conducted on five major ETEC adhesins structural subunits (FaeG, FanC, FasA, FimF41a, and FedF). Dominant epitopes were selected and concatenated via flexible linkers, incorporating the PADRE sequence and LTb adjuvant to design a multi-epitope fusion antigen (MEFA). The recombinant MEFA protein was expressed in a prokaryotic system. Furthermore, molecular dynamics simulations, docking, and immune simulations assessed structural stability and immunogenicity. Immunoreactivity was tested by Western blot. Murine immunization evaluated antibody responses, lymphocyte proliferation, cytokine secretion, and protection against ETEC challenge. Results: Structural modeling showed an extended conformation, with docking and simulations indicating strong immune activation. Western blot confirmed MEFA immunoreactivity. MEFA induced high antigen-specific antibody titers, enhanced splenocyte proliferation, and increased IFN-γ and IL-4 secretion, indicating a Th2-biased response in mice. Vaccinated mice survived lethal ETEC challenge and maintained intestinal integrity. Conclusions: The MEFA candidate vaccine effectively induces robust humoral and cellular immune responses and provides protection against ETEC infection, representing a promising strategy for next-generation multivalent ETEC vaccines. Full article

(This article belongs to the Special Issue Bacterial and Viral Infections: Current Challenges and Vaccine Innovations)

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4 pages, 156 KB

Open AccessCorrection

Correction: Omole et al. Safety, Tolerability, and Immunogenicity of the Pneumococcal Vaccines PPSV23 or PCV15 Co-Administered with a Booster Dose of mRNA-1273 SARS-CoV-2 Vaccine in Healthy Adults ≥50 Years of Age. Vaccines 2025, 13, 192

by Tosin Omole, Enrique Pelayo, Aaron S. Weinberg, Spyros Chalkias, Zelalem Endale, Gretchen Tamms, Tina M. Sterling, Lori Good, Tulin Shekar, Morgan Johnson, Natalie Banniettis, Ulrike K. Buchwald and Alejandra Esteves-Jaramillo

Vaccines 2025, 13(10), 1056; https://doi.org/10.3390/vaccines13101056 - 16 Oct 2025

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Abstract

The authors would like to make the following corrections to this published paper [...] Full article

13 pages, 479 KB

Open AccessArticle

Effect of Influenza Vaccination on Mortality and Heart Failure Hospitalization in Heart Failure Patients

by Chatpetch Maneesopit, Arintaya Phrommintikul, Jackrapong Bruminhent, Ammarin Thakkinstian and Teerapat Yingchoncharoen

Vaccines 2025, 13(10), 1055; https://doi.org/10.3390/vaccines13101055 - 15 Oct 2025

Viewed by 581

Abstract

Background: The association of influenza vaccination and heart failure (HF) hospitalization and mortality in Thai HF patients is unknown. Objective: We wished to investigate associations between receiving an influenza vaccine and all-cause death or HF hospitalization in HF patients. Methods: We retrospectively reviewed [...] Read more.

Background: The association of influenza vaccination and heart failure (HF) hospitalization and mortality in Thai HF patients is unknown. Objective: We wished to investigate associations between receiving an influenza vaccine and all-cause death or HF hospitalization in HF patients. Methods: We retrospectively reviewed medical records from two large tertiary-care centers in Thailand (Ramathibodi Hospital and Maharaj Nakorn Chiang Mai Hospital) with newly diagnosed heart failure between 2013 and 2020 in an outpatient clinic. We examined the relationship between influenza vaccination and outcomes in a propensity-adjusted model. Results: Of 588 patients, 181 (31%) received an influenza vaccination. During a median follow-up of 57 months, influenza vaccination was associated with a 56% reduction in the risk of HF hospitalization or death (HF hospitalization or all-cause death: HR: 0.44; 95% CI: 0.31–0.63; p < 0.001) in an unadjusted analysis. After propensity score adjustment, influenza vaccination, however, was not associated with a reduced risk of all-cause death but was associated with a reduced risk of HF hospitalization (ATE: 3.06 years; 95% CI: 0.14 to 5.98; p = 0.04). Conclusions: In patients with HF, influenza vaccination was not associated with a reduced risk of the composite of all-cause death or HF hospitalization after adjustment for confounders. Full article

(This article belongs to the Section Influenza Virus Vaccines)

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11 pages, 213 KB

Open AccessArticle

Self-Reporting of Post-Vaccination Symptoms in the COVID-19 Vaccination Process for Teachers in a North Region of Poland

by Tadeusz Jędrzejczyk, Anna Tyrańska-Fobke, Agata Konieczna, Daniel Ślęzak, Monika Waśkow, Katarzyna Brzychcy, Piotr Robakowski and Marlena Robakowska

Vaccines 2025, 13(10), 1054; https://doi.org/10.3390/vaccines13101054 - 14 Oct 2025

Viewed by 473

Abstract

Background: Poland was one of only 10 European countries listed teachers as a priority group for vaccination against COVID-19 among National Vaccination Program (NVP). The aim of this study was to analyse post-vaccination symptoms self-reported by teachers vaccinated under the national COVID-19 vaccination [...] Read more.

Background: Poland was one of only 10 European countries listed teachers as a priority group for vaccination against COVID-19 among National Vaccination Program (NVP). The aim of this study was to analyse post-vaccination symptoms self-reported by teachers vaccinated under the national COVID-19 vaccination programme. Methods: The presented cross-sectional survey was conducted among teachers from all levels of education in public and non-public institutions, who received the SARS-CoV-2 virus vaccination campaign with the vaccine from AstraZeneca as part of the NVP. The survey was conducted using an original, self-designed questionnaire prepared for this study and distributed to teachers in the form of an online survey via email. Bayesian logistic and linear regression were used to estimate the relationship between predictors and dependent variables. Results: A total of 4622 teachers took part in the survey. Of this number, 3908 teachers declared that they had taken the vaccine. (84.5%). In the study group, self-reported late post-vaccination reactions were very strongly [logBF > 3.4] associated with both gender and age. In contrast, self-reporting of serious late post-vaccination symptoms other than fever was very strongly associated only with gender. Only a small proportion of teachers (from 1.45% to 5.34% depending on age and gender) self-reported immediate post-vaccination reaction (up to 15 min after injection). Conclusions: Self-reporting of symptoms is a valuable tool for monitoring the effectiveness and safety of vaccinations and can also contribute to increased satisfaction with the vaccination process, especially when patients are made aware that post-vaccination symptoms are a natural sign of the body’s immune response. Full article

(This article belongs to the Special Issue Safety and Side Effects in SARS-CoV-2 Vaccine)

14 pages, 3692 KB

Open AccessArticle

B7 Family Molecule VSIG4 Regulates Pulmonary Anti-Influenza Immune Responses via C-Type Lectin Signal Pathway

by Jianxin Zhu, Dan Lu, Liangyan Zhang, Zhili He, Tianxinyu Ma, Yakun Sun, Wenjing Yu, Xiaolan Yang, Yeqing Tu, Yitai Fang, Deyu Li, Rui Zheng, Tao Li, Jin Zhao and Hui Wang

Vaccines 2025, 13(10), 1053; https://doi.org/10.3390/vaccines13101053 - 14 Oct 2025

Viewed by 576

Abstract

Background: As the member of the B7 family, V-set and immunoglobulin domain-containing 4 (VSIG4) plays an essential role in regulating immune responses against bacterial infection, autoimmune disease, and chronic viral infection. However, the role of VSIG4 in acute viral infections remains largely [...] Read more.

Background: As the member of the B7 family, V-set and immunoglobulin domain-containing 4 (VSIG4) plays an essential role in regulating immune responses against bacterial infection, autoimmune disease, and chronic viral infection. However, the role of VSIG4 in acute viral infections remains largely unclear. Methods: Here, we constructed a gene-targeted VSIG4-deficient mouse model and then infected it with influenza to explore the detailed VSIG4-involved mechanism. Results: Our results demonstrated that the gene-deficient mice exhibited reduced survival rates, ranging from 25% to 50%, after being infected with different influenza virus strains. At the sites of infection, an increased number of CD8⁺ T cells, along with heightened expression of pro-inflammatory cytokines, e.g., Il-6 and TNFα, may have contributed to tissue damage. The recombinant VSIG4 protein slightly improved protection from the influenza challenge, suggesting regulatory functions of VSIG4 during infection. Using in vitro cell models, we show that the type C lectin receptor pathway member DC-SIGNR1 (CD209) is an essential factor during acute virus infection. The affinity and CO-IP tests indicated an interaction between CD209 and VSIG4, but not through protein modification. Conclusions: Therefore, VSIG4 functionally protected mice by regulating the type C lectin receptor pathway to inhibit excessive Th1 immune responses and inflammation. Our findings highlight the importance of considering immune homeostasis in the development of therapies for severe infections. Full article

(This article belongs to the Section Pathogens-Host Immune Boundaries)

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19 pages, 5486 KB

Open AccessArticle

Establishment of Immune Biobank for Vaccine Immunogenicity Prediction Using In Vitro and In Silico Methods Against Porcine Reproductive and Respiratory Syndrome Virus

by Chaitawat Sirisereewan, John J. Byrne, Lanre Sulaiman, Abigail Williams, Ben M. Hause, Juliana Bonin Ferreira, Glen W. Almond, Benjamin Gabriel, Anne S. De Groot, Tobias Käser, Gustavo Machado and Elisa Crisci

Vaccines 2025, 13(10), 1052; https://doi.org/10.3390/vaccines13101052 - 14 Oct 2025

Viewed by 698

Abstract

Background/Objectives: Porcine reproductive and respiratory syndrome virus (PRRSV) remains one of the most economically significant pathogens in the global swine industry. Despite the availability of commercial vaccines for over three decades, they fail to induce sterile immunity and often provide inconsistent protection against [...] Read more.

Background/Objectives: Porcine reproductive and respiratory syndrome virus (PRRSV) remains one of the most economically significant pathogens in the global swine industry. Despite the availability of commercial vaccines for over three decades, they fail to induce sterile immunity and often provide inconsistent protection against heterologous PRRSV strains. This study aimed to predict vaccine immunogenicity by detecting strain-specific immune responses that related to an immune correlate of protection (CoP) against different PRRSV-2 strains. Methods: Post-weaning pigs were vaccinated with five commercially available PRRSV-2 vaccines or received sterile PBS injection as a control. At 28 days post-vaccination (dpv), all pigs were humanely euthanized for large-volume blood collection to isolate peripheral blood mononuclear cells (PBMCs) and plasma, establishing the immune bank. PBMCs and plasma from each group were then tested against six PRRSV-2 strains to evaluate immune responses. In addition, T cell epitope coverage between vaccine and field PRRSV-2 strains was assessed using the EpiCC (in silico) tool to enhance predictive capacity. Results: While neutralizing antibodies were undetectable in all vaccinated pigs at 28 dpv, PRRSV-specific IFNγ–producing cells were detected at various levels in each vaccinated group following restimulation with different PRRSV-2 strains. Additionally, a positive correlation was observed for the EpiCC coverage of the N gene and mean IFNγ responses to VR2332 (SLA class I and II) and NC24-6 (SLA class II). Conclusions: The PRRSV immune bank demonstrated potential as a tool for predicting vaccine immunogenicity against different PRRSV-2 strains and EpiCC provides additional information on T cell epitope cross conservation. The combined approach may provide a valuable framework for selecting PRRSV vaccines for more effective prevention and control in endemic areas. Full article

(This article belongs to the Special Issue Animal Vaccines: 2nd Edition)

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17 pages, 444 KB

Open AccessArticle

Boosting RSV Immunization Uptake in The Netherlands: (Expectant) Mothers and Healthcare Professionals’ Insights on Different Strategies

by Lisanne van Leeuwen, Lisette Harteveld, Lucy Smit, Karlijn Vollebregt, Debby Bogaert and Marlies van Houten

Vaccines 2025, 13(10), 1051; https://doi.org/10.3390/vaccines13101051 - 14 Oct 2025

Viewed by 576

Abstract

Background: Respiratory syncytial virus (RSV) is a major cause of infant respiratory illness, leading to significant hospitalizations. Two preventive strategies exist: maternal vaccination and a long-acting monoclonal antibody for neonates. In The Netherlands, neonatal immunization is planned to start from autumn 2025 onward, [...] Read more.

Background: Respiratory syncytial virus (RSV) is a major cause of infant respiratory illness, leading to significant hospitalizations. Two preventive strategies exist: maternal vaccination and a long-acting monoclonal antibody for neonates. In The Netherlands, neonatal immunization is planned to start from autumn 2025 onward, contingent on acceptance by parents and healthcare professionals. Maternal vaccination is already available at own costs. Understanding acceptance, perceptions, and barriers is critical for effective implementation. This study explores these factors to inform strategies for optimal uptake. Methods: This mixed-method study involved semi-structured online interviews with 21 (expectant) mothers (EMs) and 32 healthcare professionals (HCPs) involved in maternal and neonatal care (e.g., pediatricians, youth doctors/nurses, obstetricians, midwives, and general practitioners) and a quantitative descriptive analysis of factors influencing EM choices. Interviews were transcribed and thematically analyzed. Results: Both EMs and HCPs showed strong support for RSV immunization, with a preference for maternal vaccination or a combined approach. Concerns about neonatal injections during the sensitive postpartum period and unfamiliarity with newborn injections (e.g., vitamin K) influenced preferences. EMs noted hesitation about additional pregnancy/postpartum vaccinations, emphasizing the importance of well-timed interventions. HCPs highlighted logistical challenges, such as defining responsibilities, navigating National Immunization Program (NIP) changes, and ensuring readiness. All interviewed individuals value the option to choose between strategies, necessitating informed decision-making and respect for preferences. EMs make their final decision together with their partner, supported by expert information and their personal environment. Conclusions: Support for RSV immunization is high, with maternal vaccination preferred, though neonatal immunization is accepted if appropriately timed. Providing clear personalized and consistent information, heightened public awareness of RSV’s impact, respecting individual choices, and offering options are key to maximizing uptake. Full article

(This article belongs to the Special Issue Vaccination Strategies for Global Public Health)

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16 pages, 1001 KB

Open AccessArticle

Prevalence of High-Risk Human Papillomaviruses (HPV) in Slovenian Women Attending Organized National Cervical Cancer Screening 14 Years After Implementation of the National HPV Vaccination Program

by Mateja Lasič, Anja Oštrbenk, Špela Smrkolj, Klara B. Bohinc, Ana Pflaum and Mario Poljak

Vaccines 2025, 13(10), 1050; https://doi.org/10.3390/vaccines13101050 - 13 Oct 2025

Viewed by 789

Abstract

Background/Objectives: To assess overall and type-specific HPV vaccine effectiveness in central and eastern Europe (CEE), the age-stratified prevalence of cervical HPV infection was determined among Slovenian women aged 20 to 64 attending a cervical cancer screening program 14 years after implementation of [...] Read more.

Background/Objectives: To assess overall and type-specific HPV vaccine effectiveness in central and eastern Europe (CEE), the age-stratified prevalence of cervical HPV infection was determined among Slovenian women aged 20 to 64 attending a cervical cancer screening program 14 years after implementation of a national HPV vaccination program, which was then compared with 2009–2010 pre-vaccination data using the same methodological approach. Methods: Cervical samples of 4419 women were tested in 2023–2025 using the clinically validated Alinity m HR HPV Assay, and individual HPV types were determined by the Allplex HPV HR Detection assay. Results were compared with 2009–2010 pre-vaccination data generated using the same assay on an age-range matched cohort of women. Results: The overall prevalence of the 14 Alinity-targeted HPV types was 10.0% in 2023–2025 versus 13.3% in 2009–2010 (p < 0.001). HPV16 prevalence declined from 3.5% to 1.5% (p < 0.001), and HPV18 prevalence from 1.1% to 0.5% (p = 0.005). In women aged 20 to 24 with 40% uptake of quadrivalent HPV vaccine, overall HPV prevalence dropped from 25.3% to 12.8% (p < 0.001). No single case of HPV16/HPV18 infection was detected among vaccinated women. Conclusions: The first large-scale, systematic, and methodologically consistent study of HPV vaccine effectiveness in CEE showed a substantial reduction in high-risk HPV prevalence after implementation of the national program, with the greatest decline among women aged 20 to 24, who harbored the highest HPV burden in the pre-vaccination era. These locally acquired data will considerably inform public health strategies on cervical cancer elimination in CEE. Full article

(This article belongs to the Special Issue HPV Vaccination and Primary HPV Screening)

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1 pages, 122 KB

Open AccessCorrection

Correction: Castro et al. Stakeholders’ Understanding of European Medicine Agency’s COVID-19 Vaccine Information Materials in EU and Regional Contexts. Vaccines 2023, 11, 1616

by Indiana Castro, Marie Van Tricht, Nicole Bonaccorso, Martina Sciortino, Juan Garcia Burgos, Claudio Costantino and Rosa Gonzalez-Quevedo

Vaccines 2025, 13(10), 1049; https://doi.org/10.3390/vaccines13101049 - 13 Oct 2025

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The author would like to make the following correction to this publication [...] Full article

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Immunogenicity and Contraceptive Potential of a Classical Swine Fever Viral Vector Live Vaccine Strain Containing Pig Gonadotropin-Releasing Hormone

by Dong-Jun An, Ji-Hee Shin, SeEun Choe, Young-Hyeon Lee, Min-Kyung Jang, Byung-Hyun An, Gyu-Nam Park, Yun-Sang Cho and Kyung-Soo Chang

Vaccines 2025, 13(10), 1048; https://doi.org/10.3390/vaccines13101048 - 12 Oct 2025

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Abstract

Background: Classical swine fever virus (CSFV) is a highly contagious and fatal disease in pigs and wild boars. While hunting and bait vaccination are effective for CSFV eradication, additional strategies are needed to control wild boar populations. This study aimed to develop an [...] Read more.

Background: Classical swine fever virus (CSFV) is a highly contagious and fatal disease in pigs and wild boars. While hunting and bait vaccination are effective for CSFV eradication, additional strategies are needed to control wild boar populations. This study aimed to develop an oral vaccine, Flc-LOM-GnRHx3, by inserting gonadotropin-releasing hormone (GnRH) epitopes into the Flc-LOM clone. Methods: The Flc-LOM-GnRHx3 strain was rescued from CPK cells and propagated to high titers in MDBK cells. Male boars (20 weeks old) received three doses (10^5.0 TCID₅₀/ml/dose) of Flc-LOM-GnRHx3 either orally or intramuscularly at 2-week intervals. Anti-CSFV E2 antibodies were detected via immunofluorescence and Western blotting. Results: Both vaccination routes induced anti-GnRH antibodies and reduced testosterone levels. Testis size and weight were slightly lower than controls, with seminiferous tubule and spermatid deformities observed in 52.5% of intramuscularly vaccinated pigs and 20.8% of orally vaccinated pigs. Conclusions: Flc-LOM-GnRHx3 demonstrates potential as a dual-function oral vaccine that can eradicate CSFV and impair reproductive capacity in wild boars, offering a novel approach for integrated disease control and population management. Full article

(This article belongs to the Special Issue Classical Swine Fever Virus Vaccines)

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