Vaccines

11 pages, 1303 KiB

Open AccessArticle

Pediatric Rotavirus Hospitalization Rates in the Military Health System Before and During the COVID-19 Pandemic

by Matthew D. Penfold, Sarah Prabhakar, Apryl Susi, Michael Rajnik, Cade M. Nylund and Matthew D. Eberly

Vaccines 2025, 13(5), 492; https://doi.org/10.3390/vaccines13050492 - 2 May 2025

Abstract

Background/Objectives: Rotavirus gastroenteritis is a vaccine-preventable disease that leads to hospitalization in children less than 5 years of age. Immunizations to prevent rotavirus have greatly altered the epidemiology of significant diarrheal illness. It has been reported that routine immunization rates in children were [...] Read more.

Background/Objectives: Rotavirus gastroenteritis is a vaccine-preventable disease that leads to hospitalization in children less than 5 years of age. Immunizations to prevent rotavirus have greatly altered the epidemiology of significant diarrheal illness. It has been reported that routine immunization rates in children were impacted during the COVID-19 pandemic. Contrary to this fact, rates of many childhood illnesses also decreased. Methods: The Military Health System Data Repository (MDR) contains the health records of all military beneficiaries. We queried the MDR before and during the COVID-19 pandemic to assess for alterations in immunization rates and hospitalization rates and to assess for risk factors for significant (hospitalizations) rotavirus disease. Results: Our study included a cohort of 1.27 million children under the age of 5 years old. There were 186 unique cases of rotavirus-related hospitalizations over the 5-year study period. During COVID-19 Years 1 and 2, there was a decrease in rotavirus-related hospitalizations compared to the pre-pandemic period. During Year 3, there was a return to the pre-pandemic level of rotavirus hospitalization rates. Patients in the northern United States were less likely to be hospitalized from rotavirus when compared to those in the south. The patients at greatest risk were the youngest beneficiaries. Rotavirus vaccination rates declined in this age group during all three years of the pandemic. Conclusions: As the pandemic resulted in less frequent rotavirus immunizations in the Military Health System (MHS), there was not an increase in rotavirus-related hospitalizations above the pre-pandemic baseline. Full article

(This article belongs to the Section Vaccines against Infectious Diseases)

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21 pages, 4677 KiB

Open AccessArticle

Genetic Sequencing of a Bacterial Pneumonia Vaccine Produced in 1916

by Yongli Xiao, Sebastian M. Gygli, Tomoko Y. Steen and Jeffery K. Taubenberger

Vaccines 2025, 13(5), 491; https://doi.org/10.3390/vaccines13050491 - 2 May 2025

Abstract

Background/Objectives: Bacterial vaccines were first developed and used in the late 1800s to prevent chicken cholera and anthrax. Bacterial pneumonia vaccines were widely used during the 1918 influenza pandemic, despite the influenza A/H1N1 virus not yet being identified. Studies showed that bacterial [...] Read more.

Background/Objectives: Bacterial vaccines were first developed and used in the late 1800s to prevent chicken cholera and anthrax. Bacterial pneumonia vaccines were widely used during the 1918 influenza pandemic, despite the influenza A/H1N1 virus not yet being identified. Studies showed that bacterial pathogens, including Haemophilus influenzae, Streptococcus pneumoniae, and Streptococcus pyogenes, contributed significantly to fatal secondary bacterial pneumonias during the pandemic. In this study, we aimed to characterize the microbial composition of two ampules of a mixed bacterial influenza vaccine produced in 1916, which were labeled as containing killed Bacillus influenzae, Pneumococci, and Streptococcus pyogenes. Methods: DNA was extracted from two 1916-era vaccine ampules, and due to low DNA yields, whole genome amplification (WGA) was performed prior to construction of Illumina sequencing libraries. Deep sequencing was conducted, followed by bioinformatic analysis to identify bacterial DNA content. Consensus genomes were assembled for predominant species, and further analyzed for serotype, phylogeny, and antibiotic resistance genes. Results: The amount of recoverable DNA from these century-old vaccine ampules was limited. The sequencing results revealed minimal detectable S. pneumoniae DNA. The first ampule contained predominantly H. influenzae DNA, while the second vial primarily contained Enterococcus faecium DNA, in addition to S. pyogenes DNA. Consensus genomes for H. influenzae, S. pyogenes, and E. faecium were assembled and analyzed for serotype, phylogeny, and antibiotic resistance genes. Conclusions: This study presents the first genomic analysis of century-old bacterial pneumonia vaccine ampules from the 1918 influenza pandemic era. The findings provide a unique historical perspective on early vaccine formulations and highlight the limitations of early vaccine production. Full article

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17 pages, 1140 KiB

Open AccessArticle

Association Between Human Papillomavirus Vaccination and the Risk of Hashimoto’s Thyroiditis: A Cross-Sectional Study

by Yifan Yin, Liang Ye, Min Chen, Hao Liu and Jingkun Miao

Vaccines 2025, 13(5), 490; https://doi.org/10.3390/vaccines13050490 - 30 Apr 2025

Abstract

Background/Objectives: Concerns about the occurrence of autoimmune diseases are one of the main reasons influencing the uptake of the human papillomavirus (HPV) vaccine. Limited evidence exists regarding the relationship between HPV vaccination and the risk of Hashimoto’s thyroiditis (HT). Therefore, the purpose [...] Read more.

Background/Objectives: Concerns about the occurrence of autoimmune diseases are one of the main reasons influencing the uptake of the human papillomavirus (HPV) vaccine. Limited evidence exists regarding the relationship between HPV vaccination and the risk of Hashimoto’s thyroiditis (HT). Therefore, the purpose of this study was to examine the association between HPV vaccination and the risk of HT development in American women. Methods: Using the National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2012, we conducted a cross-sectional study of 2717 women aged 18–59 with comprehensive data on relevant HPV vaccination status, HPV DNA vaginal swab results, and thyroid function. The relationship between HPV vaccination and the risk of HT development was explored by weighted logistic regression, while the association between HPV vaccination and thyroid peroxidase antibodies (TPOAb)/thyroglobulin antibodies (TGAb) levels was analyzed by weighted linear regression. Results: In the fully adjusted model, HPV vaccination was associated with an 87% decrease in the risk of developing HT (OR 0.13; 95% CI 0.02, 0.76). Furthermore, weighted linear regression demonstrated significant negative associations between HPV vaccination and TPOAb levels (−22.27 (−34.86, −9.68), p = 0.001) and TGAb levels (−7.53 (−14.88, −0.18), p = 0.045). HPV vaccination was significantly negatively correlated with the risk of HT development and TPOAb/TGAb levels. Conclusions: We advocate for adherence to vaccination guidelines, which could confer dual protective benefits against HPV and potentially reduce the risk of HT development. Full article

(This article belongs to the Section Human Papillomavirus Vaccines)

10 pages, 531 KiB

Open AccessArticle

Influenza Vaccine Uptake and Associated Hospitalization Risk in Older Adults with or Without Dementia: Differences Between at Home-Living and Nursing Home Residents in Lombardy, Italy

by Lorenzo Blandi and Carlo Signorelli

Vaccines 2025, 13(5), 489; https://doi.org/10.3390/vaccines13050489 - 30 Apr 2025

Abstract

Objective: Our population-based cohort study aims to compute the uptake of the influenza vaccine and the associated risk of hospitalization for respiratory diseases of infectious origin based on the residency setting and dementia status of people aged 65 or over. Methods: We conducted [...] Read more.

Objective: Our population-based cohort study aims to compute the uptake of the influenza vaccine and the associated risk of hospitalization for respiratory diseases of infectious origin based on the residency setting and dementia status of people aged 65 or over. Methods: We conducted a retrospective cohort study on the whole population of residents aged ≥65 in Lombardy, the most populated Italian region. Using region-wide administrative data, we computed the seasonal prevalence of vaccination for influenza from 1 October 2022 to 30 April 2023. To estimate the risk of hospitalization, we applied Fine-Gray sub-distribution hazard models, accounting for the competing risk of death and adjusting for confounders. Results: Our study analyzed 2,420,279 individuals aged 65+ in Lombardy. Overall, 51.4% received an influenza vaccination in 2022–2023. Among residents living at home, 50.8% were vaccinated, while nursing home residents had an uptake of 74.0%. People living with dementia reported a vaccination coverage of 62.6%, and vaccination rates were higher among those residing in nursing homes than those who lived at home. The adjusted sub-hazard ratios (SHRs) showed higher hospitalization risks of 1.88 for unvaccinated individuals with dementia and 1.74 for unvaccinated individuals without dementia living at home. In nursing homes, the SHR for respiratory hospitalization was 2.20 for individuals without dementia and 2.40 for dementia patients. Vaccination reduced risks across all groups, but disparities persisted. Conclusions: People living with dementia were more likely to be hospitalized for respiratory diseases. However, they reported an influenza vaccination coverage that was below expectations and similar to the general population, both in nursing homes and home-living settings. Public health institutions should extend and mention dementia as a higher-risk condition. Full article

(This article belongs to the Special Issue SARS-CoV-2, Influenza and Other Respiratory Viruses: Preventive Measures Affecting the Determinants of Health and Disease)

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11 pages, 358 KiB

Open AccessArticle

Vaccine-Induced Humoral and Cellular Response to SARS-CoV-2 in Multiple Sclerosis Patients on Ocrelizumab

by Jelena Drulovic, Olivera Tamas, Neda Nikolovski, Nikola Momcilovic, Vanja Radisic, Marko Andabaka, Bojan Jevtic, Goran Stegnjaic, Milica Lazarevic, Nikola Veselinovic, Maja Budimkic, Sarlota Mesaros, Djordje Miljkovic and Tatjana Pekmezovic

Vaccines 2025, 13(5), 488; https://doi.org/10.3390/vaccines13050488 - 30 Apr 2025

Abstract

Background/Objectives: The aim of our study was to investigate B cell and T cell responses in people with multiple sclerosis (PwMS) treated with ocrelizumab, a humanized anti-CD20 antibody, who were vaccinated with second and/or booster doses of various vaccine brands against COVID-19. [...] Read more.

Background/Objectives: The aim of our study was to investigate B cell and T cell responses in people with multiple sclerosis (PwMS) treated with ocrelizumab, a humanized anti-CD20 antibody, who were vaccinated with second and/or booster doses of various vaccine brands against COVID-19. Additionally, we detected the outcomes related to COVID-19 in PwMS after vaccination, based on follow-up for at least 12 months. Methods: We enrolled 91 PwMS on ocrelizumab and 42 healthy controls (HCs) in a prospective, single-center study, conducted at the Clinic of Neurology, UCCS, between January 2022 and October 2024. The serological responses were measured using the spike receptor-binding domain (RBD) Architect SARS-CoV-2 IgG Quant kit (Abbot), and cellular responses were measured by quantifying IFN-γ secretion in blood incubated with SARS-CoV-2 antigens. Results: A total of 58.2% (53/91) of PwMS on ocrelizumab and 100% of the HCs (42/42) were seropositive after a second or booster vaccination (p < 0.001), irrespective of the vaccine brand received. Anti-spike antibody levels were significantly lower in PwMS on ocrelizumab compared to the HCs (p < 0.001), again irrespective of the vaccine type. Interferon-γ responses were detected in 95.6% of the PwMS receiving ocrelizumab therapy and 97.6% of HCs after vaccination (p = 0.570). In our cohort, PCR-confirmed SARS-CoV-2 infections after vaccination occurred in a similar proportion of the PwMS (45/91, 49.5%) and HCs (15/32, 46.9%) (p = 0.139). Most of the PwMS (36/45, 79.2%) and HCs (13/15, 87.8%) had COVID-19 of mild severity. Conclusions: PwMS treated with ocrelizumab developed diminished humoral and robust cellular responses following two and three SARS-CoV-2 vaccinations. The obtained immunity after SARS-CoV-2 vaccination may translate into lower incidence and severity of COVID-19. Full article

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

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14 pages, 2109 KiB

Open AccessArticle

Safety and Immunogenicity of the Attenuated Yellow Fever Vaccine in Several Neotropical Primate Species

by Nayara Ferreira de Paula, André Duarte Vieira, Daniel Oliveira dos Santos, Lucas dos Reis de Souza, Carlyle Mendes Coelho, Herlandes Penha Tinoco, Paula Cristina Senra Lima, Rafael Otávio Cançado Motta, Valéria do Socorro Pereira, Marcelo Pires Nogueira de Carvalho, Camilla Bayma Fernandes, Adriana de Souza Azevedo, Matheus Soares Arruda, Thais Alkifeles Costa, Betania Paiva Drumond, Fabiola de Oliveira Paes Leme, Marcos da Silva Freire, Tatiane Alves da Paixão, Ayisa Rodrigues Oliveira and Renato Lima Santos

Vaccines 2025, 13(5), 487; https://doi.org/10.3390/vaccines13050487 - 30 Apr 2025

Abstract

Background/Objective: Yellow fever (YF) is an acute infectious disease caused by the yellow fever virus which is transmitted by mosquitoes. Neotropical primates are susceptible to infection, which is often presented as epizootic outbreaks. The aim was to evaluate and characterize the immune response [...] Read more.

Background/Objective: Yellow fever (YF) is an acute infectious disease caused by the yellow fever virus which is transmitted by mosquitoes. Neotropical primates are susceptible to infection, which is often presented as epizootic outbreaks. The aim was to evaluate and characterize the immune response against YF in different species of neotropical primates from the Belo Horizonte Zoo. Methods: Vaccine 17DD was administered to 24 neotropical primates, with a single subcutaneous dose. Clinical exams, RNAemia, and detection of IgG and neutralizing antibodies against YFV were performed. In addition, an ethogram was performed to assess clinical changes and animal welfare. Results: At 4 days post-vaccination, RNAemia was detected in nine animals. There was seroconversion and persistence of immune response in Alouatta guariba clamitans, Sapajus xanthosternos, Saguinus imperator and Aotus infulatus. However, the vaccine was not immunogenic for Lagothrix cana. In Pithecia irrorata seroconversion did not persist long term, while the Ateles sp. had a transient immune response. No significant clinical manifestations were observed in any of the vaccinated animals. Conclusions: This study demonstrated a safe, immunogenic and persistent immune response induced by the attenuated 17DD vaccine strain in A. guariba clamitans, S. xanthosternos, S. imperator, and A. infulatus. Full article

(This article belongs to the Special Issue A One-Health Perspective on Immunization Against Infectious Diseases)

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15 pages, 740 KiB

Open AccessArticle

by Yana Chervona, Wen Shen, Shambhunath Choudhary, Victoria Markiewicz, Peter C. Giardina and Cynthia M. Rohde

Vaccines 2025, 13(5), 486; https://doi.org/10.3390/vaccines13050486 - 30 Apr 2025

Abstract

Background: 2-Phenoxyethanol (2-PE) has been safely included as a preservative and/or stabilizer in more than thirty vaccine formulations at amounts ranging from 0.5 to 5 mg per dose; however, the nonclinical safety data publicly available for intramuscular (IM) or subcutaneous (SC) administration are [...] Read more.

Background: 2-Phenoxyethanol (2-PE) has been safely included as a preservative and/or stabilizer in more than thirty vaccine formulations at amounts ranging from 0.5 to 5 mg per dose; however, the nonclinical safety data publicly available for intramuscular (IM) or subcutaneous (SC) administration are relatively limited. Here, in addition to the available clinical and nonclinical data for 2-PE, we summarize the nonclinical safety data of experimental 13vPnC (Prev(e)nar 13) formulations with or without 2-PE. Methods: Two repeat-dose toxicity studies in rabbits, one for a 2-PE-free formulation of 13vPnC and the other for an MDV formulation of 13vPnC with 5 mg/dose 2-PE, were conducted as part of an overall nonclinical safety package for vaccine development. The studies were designed and conducted in compliance with the relevant guidelines and regulations. Results: In repeat-dose toxicity studies in rabbits, five IM administrations of a preservative-free 13vPnC single-dose syringe formulation or a 13vPnC multi-dose vial (MDV) formulation containing 5 mg 2-PE/0.5 mL dose were well tolerated with no systemic toxicity. Robust serotype-specific IgG antibody responses to each of the 13 pneumococcal serotypes were also confirmed for both formulations. The observations for the 13vPnC MDV including local inflammatory reaction, increases in fibrinogen, and increased splenic germinal centers were nonadverse, reversible, and consistent with findings previously observed for the IM administration of vaccines, including the 2-PE-free 13vPnC single-dose syringe formulation. Conclusions: Together with the other available nonclinical and clinical data of 2-PE and vaccine formulations containing 2-PE and following the 3Rs principle, our risk-assessment-based recommendation is that no additional nonclinical safety studies are needed when evaluating a 2-PE-containing presentation of a previously well-characterized vaccine product if the amount of 2-PE is ≤10 mg/dose. Full article

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

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21 pages, 807 KiB

Open AccessSystematic Review

Health Equity and Human Papillomavirus Vaccine Interventions for Adolescents: A Systematic Review

by Sarah B. Maness, Lois Coleman Carpenter, Idara Akpan, Nubwa St. James, Daniela Romero-Cely, G. J. Corey Harmon, Miranda Cano and Erika L. Thompson

Vaccines 2025, 13(5), 485; https://doi.org/10.3390/vaccines13050485 - 30 Apr 2025

Abstract

Background/Objectives: Human papillomavirus (HPV) causes multiple types of cancer, and demographic-based inequities in HPV-related cancers persist. Behavioral interventions have increased HPV vaccination uptake, yet it is unclear how intervention effects vary by demographics. The purpose of this study was to examine whether existing [...] Read more.

Background/Objectives: Human papillomavirus (HPV) causes multiple types of cancer, and demographic-based inequities in HPV-related cancers persist. Behavioral interventions have increased HPV vaccination uptake, yet it is unclear how intervention effects vary by demographics. The purpose of this study was to examine whether existing HPV vaccine interventions for adolescents have unequal effects on HPV vaccine uptake. Methods: We searched MEDLINE via PubMed, PsycINFO, CINAHL, Scopus, and Cochrane CENTRAL in October 2023. The search strategy combined keywords and subject terms for HPV vaccine, interventions/health promotion, and adolescents. Studies were included in final analyses if they were peer-reviewed, published in the US between 2006 and 2023, included outcome measures from an evidence-based HPV vaccination intervention, included adolescents aged 9–17, and demographic variables for age, race/ethnicity, income/SES, or geographic region. Studies were excluded if they were review articles, abstract-only, dissertations or theses, non-English language, non-US-based, or outside the age range of 9–17. Studies were also excluded if they did not include an intervention, outcome evaluation measures, or demographic measures. The screening and extraction processes were independently performed by multiple reviewers using Covidence software. Results: Ultimately, 74 articles were included for full extraction. Sex was the most common demographic variable analyzed by the HPV vaccine (n = 38), followed by race/ethnicity (n = 15), income/SES (n = 6), and geographic region (n = 6). Conclusions: Few interventions assess whether intervention results differ by demographics, making it unclear whether these interventions reduce health inequities. This review included a wide variation in study designs, limiting our ability to uniformly assess study conclusions. Full article

(This article belongs to the Special Issue Vaccines and Vaccination: HIV, Hepatitis Viruses, and HPV)

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16 pages, 3094 KiB

Open AccessArticle

The COVID-19 Vaccination Rollout in Tanzania: The Role of Coordination in Its Success

by Fredrick Rwegerera, Mwendwa Mwenesi, Belinda J. Njiro, Florian Tinuga, Pricilla Kinyunyi, Mary Rose Giattas, Alice Christensen, Ntuli Kapologwe, Adam Meshack, Joseline Ishengoma, Sophia A. Kagoye, Mwinyi I. Msellem, Mwanahamisi Hassan Magwangwala, Fatma Mohammed Kabole, Daniel Ali and Chizoba Wonodi

Vaccines 2025, 13(5), 484; https://doi.org/10.3390/vaccines13050484 - 30 Apr 2025

Abstract

Background: The national rollout of a vaccine is a complex and significant undertaking, made more challenging when the health system is experiencing shock, such as in a pandemic. Tanzania had relative success in its COVID-19 vaccination rollout compared to other African countries. [...] Read more.

Background: The national rollout of a vaccine is a complex and significant undertaking, made more challenging when the health system is experiencing shock, such as in a pandemic. Tanzania had relative success in its COVID-19 vaccination rollout compared to other African countries. Objectives: To better understand factors that contributed to this success, we examined the role of coordination (one of the six immunization system building blocks) on the outcomes of the national vaccine rollout. Methods: We obtained qualitative information from the published literature, COVID-19 vaccination program documents for Tanzania Mainland and Zanzibar, and reports from two documentation workshops with national, regional, and district stakeholders from the government, partners, academia, and civil society. Triangulating this information, we describe the COVID-19 vaccination coordination structure, the roles and responsibilities of its members, and the changes in their engagement and activities over the 18 months following the introduction of the COVID-19 vaccine. We also obtained quantitative data from the CHANJOCOVID system to analyze time trends in national COVID-19 vaccine coverage rates for the period August 2021 to December 2022. Results: We found that Tanzania had a multi-level, multi-partner integrated coordination mechanism that provided strategic direction, oversight, and guidance for the vaccination rollout. The coordination structure was initially weak but strengthened over time. Based on the level of coordination activities undertaken, we identified three periods marking different strengths of the coordination mechanisms, these corresponded with different trends in vaccination coverage in the mainland. In the first period (July–December 2021), the coordination mechanism was weak, and vaccine coverage was low, with only 3% of the target population vaccinated on the mainland. In the second period (January–May 2022), when stakeholder engagement was expanded and the coordination mechanism improved, there was a concurrent rise in vaccine coverage from 4% to 25%. In the third period (June–December 2022), coordination was further strengthened, and vaccination strategies were intensified; a corresponding increase in vaccine uptake was observed with coverage reaching 100% of the target population. Conclusions: Qualitative insights from the three time periods suggest a positive association between coordination strength and COVID-19 vaccine coverage. Coordination fostered collaboration, enhanced stakeholder engagement, and facilitated data-driven decision making. This enabled Tanzania to overcome complex challenges and achieve significant progress in vaccination coverage. Strong coordination and effective collaboration among stakeholders are essential mechanisms and processes to optimize vaccine delivery resources and ensure the equitable distribution and uptake of vaccines in Tanzania. Full article

(This article belongs to the Special Issue Understanding Infectious Disease Vaccinations: Implications for Health and Safety)

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13 pages, 231 KiB

Open AccessReview

Dengue Vaccine Development and Deployment into Routine Immunization

by Annelies Wilder-Smith, Thomas Cherian and Joachim Hombach

Vaccines 2025, 13(5), 483; https://doi.org/10.3390/vaccines13050483 - 29 Apr 2025

Abstract

Dengue has emerged as a significant global health threat. Despite decades of research, only two dengue vaccines—CYD-TDV (Dengvaxia) and TAK-003 (Qdenga)—have been licensed to date, with limited implementation. This paper explores and outlines strategies for integrating dengue vaccines into routine immunization programs, particularly [...] Read more.

Dengue has emerged as a significant global health threat. Despite decades of research, only two dengue vaccines—CYD-TDV (Dengvaxia) and TAK-003 (Qdenga)—have been licensed to date, with limited implementation. This paper explores and outlines strategies for integrating dengue vaccines into routine immunization programs, particularly in high-burden regions. TAK-003, a tetravalent live-attenuated vaccine, has demonstrated 61% efficacy against virologically confirmed dengue and 84% efficacy against hospitalizations in endemic settings. However, concerns remain about vaccine-enhanced disease, particularly among seronegative individuals exposed to DENV3 and DENV4. WHO recommends targeted introduction in high-transmission settings without pre-vaccination screening, while ongoing post-introduction studies will further clarify long-term safety and efficacy. Effective vaccine rollout requires a multi-pronged approach, including school-based immunization, integration with adolescent health services, and strong community engagement. Decision-making for vaccine introduction should be guided by National Immunization Technical Advisory Groups (NITAGs), local epidemiological data, and cost-effectiveness assessments. While future vaccines, including mRNA and virus-like particle candidates, are under development, optimizing the use of currently available vaccines is crucial to reducing dengue’s public health impact. Given the continued rise in cases, immediate action—combining vaccination with vector control—is essential to prevent further morbidity and mortality. Full article

(This article belongs to the Special Issue 50 Years of Immunization—Steps Forward)

15 pages, 285 KiB

Open AccessReview

Overcoming Barriers to Human Papillomavirus Vaccination in Guangdong Province, China

by Shuaijing Zhang, Shiqi Li, Jingtai Ma, Guiyuan Ji, Zhifeng Li, Siyi Chen, Fenglin Zhang, Xingfen Yang, Jianpeng Xiao, Rong Cao, Chenggang Wu and Wei Wu

Vaccines 2025, 13(5), 482; https://doi.org/10.3390/vaccines13050482 - 29 Apr 2025

Abstract

Human papillomavirus (HPV) infection remains a critical public health challenge in China, particularly in Guangdong Province, where HPV-52, 16, and 58 genotypes predominate, and male infection rates exceed 40%. Despite the successful implementation of a government-funded school-based program that has achieved 88% HPV [...] Read more.

Human papillomavirus (HPV) infection remains a critical public health challenge in China, particularly in Guangdong Province, where HPV-52, 16, and 58 genotypes predominate, and male infection rates exceed 40%. Despite the successful implementation of a government-funded school-based program that has achieved 88% HPV vaccine coverage among adolescent girls, several persistent barriers, including genotype mismatch (the free HPV vaccine covers < 50% of high-risk local strains), regional disparities (80% vs. 60% for first-dose coverage), and exclusion of males, thwart progress toward herd immunity. Financial sustainability risks pose an even more significant threat to the expansion of HPV vaccination programs, especially in Guangdong province where annual expenditures exceed CNY 200 million. This review delves into Guangdong’s pioneering efforts and proposes practical solutions: accelerating domestic multivalent HPV vaccine development, adopting gender-neutral vaccination policies, and leveraging mobile clinics for remote populations. These strategies not only provide a roadmap for China but also serve as valuable insight for other LMICs striving to overcome HPV-related inequalities. Full article

(This article belongs to the Special Issue HPV Vaccination Coverage: Problems and Challenges)

11 pages, 171 KiB

Open AccessReview

Challenges and Innovations in Pharmacovigilance and Signal Management During the COVID-19 Pandemic: An Industry Perspective

by Maria Maddalena Lino, Susan Mather, Marianna Trani, Yan Chen, Patrick Caubel and Barbara De Bernardi

Vaccines 2025, 13(5), 481; https://doi.org/10.3390/vaccines13050481 - 29 Apr 2025

Abstract

Vaccine marketing authorization holders (MAHs) are responsible for the conduction of global vaccine pharmacovigilance on their vaccine products. A safety signal is detected when a new adverse event (AE) or aspect of an AE occurs after exposure to the vaccine and warrants further [...] Read more.

Vaccine marketing authorization holders (MAHs) are responsible for the conduction of global vaccine pharmacovigilance on their vaccine products. A safety signal is detected when a new adverse event (AE) or aspect of an AE occurs after exposure to the vaccine and warrants further investigation to determine whether a causal association may exist. Signal detection and evaluation (signal management) begins at the start of vaccine development, before an MAH submits an application for authorization to regulatory authorities, continues through the course of all clinical trials, and carries on beyond development into the post-marketing phase. As long as the vaccine remains authorized anywhere in the world, pharmacovigilance continues. During the time that the COVID-19 vaccine became widely available after authorization and approval, clinical trials were also ongoing, and therefore all clinical development and post-authorization safety information was closely monitored for safety by the MAH. MAH pharmacovigilance activities were adapted to manage the unprecedented volume of safety information that became available within a very short timeframe following worldwide vaccination campaigns. No vaccine had previously been administered to such a large number of individuals in such a short time, nor had there previously been a public health vaccine experience that was the subject of so many medical and non-medical writings. The MAH’s COVID-19 vaccine signal detection methods included the continuous review of accruing clinical trial data and the quantitative and qualitative analyses of spontaneously reported experiences. Review of published and unpublished medical literature and epidemiology-based analyses such as observed vs. expected analysis based on reported adverse events following immunization (AEFIs) played key roles in pharmacovigilance and signal management. All methods of signal detection and evaluation have caveats, but when considered in totality, can advance our understanding of a vaccine’s safety profile and therefore the risk–benefit considerations for vaccinating both individuals and large populations of people. All COVID-19 vaccines authorized for use were subject to an unprecedented level of pharmacovigilance by their individual MAHs, national regulatory authorities, public health organizations, and others during the years immediately following regulatory authorization and full approval. The intense worldwide focus on pharmacovigilance and the need for MAHs and regulatory/health authorities to quickly evaluate incoming safety information, spurred frequent and timely communications between national and regional health authorities and between MAHs and regulatory/health authorities, spotlighting a unique opportunity for individuals committed to patient safety to share important accruing safety information in a collegial and less traditionally formal manner than usual. The global pandemic precipitated by the SARS-CoV-2 virus created a significant impetus for MAHs to develop innovative vaccines to change the course of the COVID-19 pandemic. Pharmacovigilance also had to meet unprecedented needs. In this article, unique aspects of COVID-19 vaccine pharmacovigilance encountered by one MAH will be summarized. Full article

(This article belongs to the Special Issue Vaccination, Public Health and Epidemiology)

12 pages, 822 KiB

Open AccessArticle

Antibody Response Against SARS-CoV-2 Spike Protein in People with HIV After COVID-19 Vaccination

by María José Muñoz-Gómez, Pablo Ryan, Marta Quero-Delgado, María Martin-Vicente, Guillermo Cuevas, Jorge Valencia, Eva Jiménez, Natalia Blanca-López, Samuel Manzano, Juan Ignacio Lazo, Vicente Mas, Mónica Vázquez, Daniel Sepúlveda-Crespo, Juan Torres-Macho, Isidoro Martínez and Salvador Resino

Vaccines 2025, 13(5), 480; https://doi.org/10.3390/vaccines13050480 - 29 Apr 2025

Abstract

Background/Objectives: People with HIV (PWH) often have a suboptimal response to vaccines, raising concerns regarding the efficacy of coronavirus disease 2019 (COVID-19) vaccines in this population. We aimed to evaluate the humoral immune response to the B.1 lineage and Omicron variant in PWH [...] Read more.

Background/Objectives: People with HIV (PWH) often have a suboptimal response to vaccines, raising concerns regarding the efficacy of coronavirus disease 2019 (COVID-19) vaccines in this population. We aimed to evaluate the humoral immune response to the B.1 lineage and Omicron variant in PWH on antiretroviral therapy (ART) following COVID-19 vaccination. Methods: We conducted a prospective study of 19 PWH on ART who received a two-dose series of the COVID-19 mRNA vaccine and a booster six months later. Participants without HIV infection (n = 25) were included as a healthy control (HC) group. The humoral response to the COVID-19 vaccine (anti-SARS-CoV-2 S IgG levels and ability to block ACE2-S interaction) against both the original B.1 lineage and the Omicron variant was assessed using immunoassays. Results: The humoral response in PWH was very strong (geometric mean fold rise, GMFR > 8) after the second dose and strong (GMFR > 4) after the booster dose for both the B.1 lineage and the Omicron variant. We found comparable humoral responses to the B.1 lineage and Omicron variant between PWH and HC groups after the second and booster doses (q-value > 0.05). The COVID-19 vaccine generated a significantly weaker humoral response against the Omicron variant compared to the B.1 lineage in both groups (q-value < 0.05). However, this response improved after the booster dose, although it remained weaker in PWH. Conclusions: PWH showed a strong humoral response to the COVID-19 vaccine against B.1 and Omicron, though the Omicron response was weaker than B.1. Booster doses in PWH improved the Omicron response, but it stayed lower than B.1. Findings confirm vaccine effectiveness in PWH, stressing the critical role of boosters and potential need for updated vaccines for variants like Omicron. Full article

(This article belongs to the Special Issue Vaccines and Vaccination: HIV, Hepatitis Viruses, and HPV)

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8 pages, 492 KiB

Open AccessOpinion

Value of Vaccinations: A Fundamental Public Health Priority to Be Fully Evaluated

by Sara Boccalini

Vaccines 2025, 13(5), 479; https://doi.org/10.3390/vaccines13050479 - 29 Apr 2025

Abstract

Introduction: Vaccinations are one of the most impactful public health interventions, saving millions of lives annually and reducing the spread of infectious diseases. Numerous vaccines are expected to become available in the future. Decision-makers will have to thoroughly evaluate them. It is essential [...] Read more.

Introduction: Vaccinations are one of the most impactful public health interventions, saving millions of lives annually and reducing the spread of infectious diseases. Numerous vaccines are expected to become available in the future. Decision-makers will have to thoroughly evaluate them. It is essential to fully comprehend the value of vaccinations to effectively and efficiently guide decisions. Methods: This work aims to highlight the multifaceted benefits of vaccination, extending beyond clinical outcomes to encompass profound economic and societal advantages. Results: Vaccinations should be considered an investment, not a cost. In comparison to other health expenditures, the vaccine costs can be considered moderate. Vaccinations can also reduce the fiscal burden by avoiding diseases, minimizing lost workdays and absenteeism, lowering disability claims, and increasing workforce productivity. The costs of non-vaccination represent a relevant issue. Vaccination also plays a key role in addressing the global challenge of antimicrobial resistance. Apart from quantifiable economic parameters, vaccines also have intangible benefits reducing pain and avoiding quality of life lost and deaths. Conclusions: Comprehensive Health Technology Assessments are required to understand the overall value of vaccinations. Full article

(This article belongs to the Special Issue Estimating Vaccines' Value and Impact)

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30 pages, 1965 KiB

Open AccessReview

EBV Vaccines in the Prevention and Treatment of Nasopharyngeal Carcinoma

by Weiwei Zhang, Chuang Wang, Yousheng Meng, Lang He and Mingqing Dong

Vaccines 2025, 13(5), 478; https://doi.org/10.3390/vaccines13050478 - 29 Apr 2025

Abstract

Epstein–Barr virus (EBV), a ubiquitous human herpesvirus, has been robustly linked to the pathogenesis of nasopharyngeal carcinoma (NPC). The mechanism of EBV-induced NPC involves complex interactions between viral proteins and host cell pathways. This review aims to comprehensively outline the mechanism of EBV-induced [...] Read more.

Epstein–Barr virus (EBV), a ubiquitous human herpesvirus, has been robustly linked to the pathogenesis of nasopharyngeal carcinoma (NPC). The mechanism of EBV-induced NPC involves complex interactions between viral proteins and host cell pathways. This review aims to comprehensively outline the mechanism of EBV-induced NPC and the latest advances in targeted EBV vaccines for prophylaxis and treatment. This review explores the intricate molecular mechanisms by which EBV contributes to NPC pathogenesis, highlighting viral latency, genetic and epigenetic alterations, and immune evasion strategies. It emphasizes the pivotal role of key viral proteins, including EBNA1, LMP1, and LMP2A, in carcinogenesis. Subsequently, the discussion shifts towards the development of targeted EBV vaccines, including preventive vaccines aimed at preventing primary EBV infection and therapeutic vaccines aimed at treating diagnosed EBV-related NPC. The review underscores the challenges and future directions in the field, stressing the importance of developing innovative vaccine strategies and combination therapies to improve efficacy. This review synthesizes current insights into the molecular mechanisms of EBV-induced NPC and the development of EBV-targeted vaccines, highlighting the potential use of mRNA vaccines for NPC treatment. Full article

(This article belongs to the Special Issue Tumor Antigen-Based Anticancer Vaccine and Immunotherapy)

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19 pages, 341 KiB

Open AccessReview

Herpes Zoster Vaccination: Insights into Efficacy, Safety, and Guidelines

by Michał Oleszko, Paweł Zapolnik and Hanna Czajka

Vaccines 2025, 13(5), 477; https://doi.org/10.3390/vaccines13050477 - 28 Apr 2025

Abstract

Background: The varicella–zoster virus (VZV) is a human herpesvirus that primarily causes varicella (chickenpox) as an initial infection, characterized by distinctive skin lesions. It can later reactivate, leading to herpes zoster (shingles). Once reactivated, VZV infection may result in serious complications, the most [...] Read more.

Background: The varicella–zoster virus (VZV) is a human herpesvirus that primarily causes varicella (chickenpox) as an initial infection, characterized by distinctive skin lesions. It can later reactivate, leading to herpes zoster (shingles). Once reactivated, VZV infection may result in serious complications, the most common being postherpetic neuralgia. Fortunately, vaccination can prevent this condition. Objectives: In this study, we provide a comprehensive analysis of zoster vaccines, including clinical trials, safety profiles, and reimbursement guidelines across various countries. Results: Our findings confirm the vaccine’s effectiveness and safety across diverse populations, aligning with previous clinical trials and real-world data, and summarize global vaccination guidelines. Full article

(This article belongs to the Special Issue Varicella and Zoster Vaccination)

14 pages, 1170 KiB

Open AccessReview

Emerging Immunotherapies in Lung Cancer: The Latest Advances and the Future of mRNA Vaccines

by Raquel Ramos and Nuno Vale

Vaccines 2025, 13(5), 476; https://doi.org/10.3390/vaccines13050476 - 28 Apr 2025

Abstract

Lung cancer is the most lethal malignancy worldwide, having the highest incidence rate. This is a heterogeneous disease classified according to its histological and molecular characteristics. Depending on these, different therapeutic approaches have already been approved for lung cancer treatment targeting genetic alterations [...] Read more.

Lung cancer is the most lethal malignancy worldwide, having the highest incidence rate. This is a heterogeneous disease classified according to its histological and molecular characteristics. Depending on these, different therapeutic approaches have already been approved for lung cancer treatment targeting genetic alterations or even the immune system. Nonetheless, other therapies are being studied to continuously improve the care and survival of lung cancer patients. Among them, immunotherapies are one of the main targets of investigation to try and combat the ability of some malignant cells to evade anti-tumor responses mediated by the immune system. Cancer vaccine development has emerged as a promising approach to strengthen the patient’s immune system and combat the disease, especially mRNA vaccines. Currently, there are several ongoing studies investigating the therapeutic efficacy of mRNA vaccines in lung cancer treatment alone or combined with other therapeutic drugs. This review aims to highlight the importance of immunotherapy in lung cancer treatment, presenting the most recent advances particularly in mRNA-based vaccines as well as the challenges and future perspectives. Full article

(This article belongs to the Special Issue Advances in Cancer Immunotherapy and Vaccines Research: 2nd Edition)

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14 pages, 670 KiB

Open AccessArticle

Epidemiological Impact of Increasing Vaccination Coverage Rate and Re-Vaccination on Pneumococcal Disease in Older Adults in Germany

by Oluwaseun Sharomi, Marion de Lepper, Sarah Mihm-Sippel, Thorsten Reuter, Claudia Solleder, Giulio Meleleo, Tufail M. Malik, Kevin M. Bakker and Rachel J. Oidtman

Vaccines 2025, 13(5), 475; https://doi.org/10.3390/vaccines13050475 - 28 Apr 2025

Abstract

Background/Objectives: The clinical impact of replacing the 23-valent pneumococcal polysaccharide vaccine (PPSV23) for the vaccination of older (≥60 years) and at-risk German adults with either the 20-valent (PCV20) or 21-valent (V116) pneumococcal conjugate vaccine (PCV) was evaluated. Methods: An age- and serotype-specific transmission [...] Read more.

Background/Objectives: The clinical impact of replacing the 23-valent pneumococcal polysaccharide vaccine (PPSV23) for the vaccination of older (≥60 years) and at-risk German adults with either the 20-valent (PCV20) or 21-valent (V116) pneumococcal conjugate vaccine (PCV) was evaluated. Methods: An age- and serotype-specific transmission model was adapted to Germany to evaluate the impact of V116 versus PCV20 vaccination on pneumococcal disease (PD) incidence, including invasive pneumococcal disease (IPD) and inpatient and outpatient non-bacteremic pneumococcal pneumonia, over 10 years. A reference strategy (PPSV23 vaccination at a constant 30% vaccine coverage rate (VCR)) was compared against eight strategies varying by PCV (PCV20 vs. V116), VCR (30% vs. 60%), with or without the PCV revaccination of previously PPSV23-vaccinated adults (0% vs. 50% revaccination). Results: Vaccination with PCV20 and V116 initially decreased PD incidence, but incidence returned to pre-vaccine levels after five and eight years, respectively. Increasing the VCR to 60% prevented this resurgence. At a 10-year time horizon, V116 with 30% VCR reduced IPD cases by 9%, inpatient NBPP cases by 10%, and outpatient NBPP cases by 7% compared to the reference strategy. PCV20 with 30% VCR reduced these cases by 6%, 5%, and 4%, respectively. Increasing the VCR to 60% and revaccinating 50% of previously PPSV23-vaccinated adults further reduced IPD cases by 14% and 13% for V116, and by 9% and 9% for PCV20. Conclusions: Increasing the vaccination coverage rate to 60% and strategically revaccinating previously PPSV23-vaccinated adults significantly enhanced the effectiveness of pneumococcal vaccines, with V116 showing greater overall reductions in disease incidence compared to PCV20 or PPSV23. Full article

(This article belongs to the Special Issue Pneumococcal Vaccines: Current Status and Future Prospects)

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24 pages, 15001 KiB

Open AccessArticle

Impact of Chitosan Nanoparticles-Coated Dendritic Cell-Based Vaccine as Cancer Immunotherapy

by Jehan S. Alrahimi, Najla S. Alotaibi, Alia M. Aldahlawi, Fatemah S. Basingab and Kawther A. Zaher

Vaccines 2025, 13(5), 474; https://doi.org/10.3390/vaccines13050474 - 28 Apr 2025

Abstract

Dendritic cells (DCs) are major contributors to generating an effective immune response due to their ability to present antigens to T cells. Recently, nanoparticles have been widely used in different medical applications, such as drug-delivery systems, to enhance the function of impaired immune [...] Read more.

Dendritic cells (DCs) are major contributors to generating an effective immune response due to their ability to present antigens to T cells. Recently, nanoparticles have been widely used in different medical applications, such as drug-delivery systems, to enhance the function of impaired immune cells. Objectives: This research aims to develop an effective antitumor DC-based vaccine by adsorption of chitosan-nanoparticles (CH-NPs) onto DCs. Methods: Undifferentiated mouse bone marrow progenitor cells were differentiated into mature DCs using cytokines and lipopolysaccharides. CH-NPs were prepared using the ionic gelation method and subsequently used to coat the stimulated DCs. The MTT assay was employed to assess the cytotoxicity of all formulations. To compare the antitumor effect of CH-NPs, DCs, and DCs-CH-NPs, mice were divided into five groups and injected with the respective vaccine formulations. Following immunization, flow cytometry was used to analyze DC and CD4⁺ T cell activation in blood and spleen tissues. Histological samples from the spleen and lymph nodes were also collected. Results: Our findings show that co-stimulatory molecules CD80/CD86 and the DC maturation marker CD83 were upregulated in the vaccinated DCs, indicating their maturation. Moreover, CD83, CD11c, and MHC-II were upregulated in blood and spleen samples in vivo. The DC-CH-NPs vaccinated group had a higher mean percentage of CD83 expression in blood samples (76.7 ± 17.1) compared to the DCs group (47.7 ± 11.0) and the CH-NPs group (37.7 ± 8.6). DC markers, particularly CD83, were highly expressed in spleen samples. Additionally, the DC-CH-NPs vaccinated group had a significantly higher number of CD4⁺ T cells (MFI = 26.1 ± 2.3) compared to the DCs (18.6 ± 1.6) and CH-NPs (13.3 ± 1.4) groups. Conclusions: The present study concludes that the DC-CH-NPs vaccine formulation can induce a potent in vivo immune response. These data may provide valuable insights for developing effective delivery systems for antitumor vaccines. Full article

(This article belongs to the Special Issue Cutting-Edge Cancer Vaccines Enhanced by Nanotechnology)

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