Vaccines

25 pages, 1022 KB

Open AccessArticle

Non-Clinical Safety of GRAd Vector-Based COVID-19 and HIV Vaccines Supports a Platform Regulatory Approach

by Reji Paalangara, Stephanie Gohin, Alexis Menard, Charlotte Amy, Wahiba Berrabah, Alexandra Rogue, Matthew A. Getz, Aljawharah Alrubayyi, Simone Battella, Angelo Raggioli, Michela Gentile, Anthea Di Rita, Alessia Noto, Giuseppina Miselli, Fabiana Grazioli, Federico Napolitano, Dhurata Sowcik, Marco Soriani, Benjamin Chmielewski, Lebohang Molife, Vincent Muturi-Kioi, Azure Tariro Makadzange, Gaurav D. Gaiha, Philippe Ancian, Jim Ackland, Antonella Folgori, Stefano Colloca and Stefania Capone Show full author list Hide full author list

Vaccines 2026, 14(2), 157; https://doi.org/10.3390/vaccines14020157 - 6 Feb 2026

Abstract

Background/Objectives: The rapid development of safe and efficacious vaccines is often hindered by extensive, mandated non-clinical safety evaluations in animals. With the aim to provide scientific evidence supporting a “vaccine platform approach”, here we present the complete non-clinical studies for two investigational [...] Read more.

Background/Objectives: The rapid development of safe and efficacious vaccines is often hindered by extensive, mandated non-clinical safety evaluations in animals. With the aim to provide scientific evidence supporting a “vaccine platform approach”, here we present the complete non-clinical studies for two investigational vaccines, GRAd-COV2 and GRAdHIVNE1, based on GRAd, a gorilla-derived group C adenoviral vector. Methods: The biodistribution of GRAd genomes following the intramuscular administration of the vaccines was assessed in rats by a sensitive qPCR method. Local tolerance and systemic toxic effects were evaluated in single- and repeated-dose toxicity studies in rabbits. Results: GRAd-COV2 and GRAdHIVNE1 were well-tolerated. Distribution was highly confined to the injection site and draining lymph nodes, and toxicity profile consisted of transient, non-adverse inflammatory responses, while the expected immune responses to the encoded antigens were successfully induced. Notably, both vaccines demonstrated a consistent safety profile despite transgene and backbone differences, comparable to other replication-defective adenoviral vectors. Conclusions: The established non-clinical safety profile of the GRAd platform provides a robust foundation for a more efficient and streamlined regulatory pathway. By leveraging this prior knowledge, future GRAd-based vaccines can achieve accelerated clinical development while fully adhering to the ethical principles of replacement, reduction, and refinement of animal use in research. Full article

(This article belongs to the Section Vaccine Advancement, Efficacy and Safety)

► Show Figures

Graphical abstract

63 pages, 861 KB

Open AccessReview

A Scoping Review of Influences on HPV Vaccine Uptake in the Rural US

by Sherri Sheinfeld Gorin, Rebecca Hyman, Courtney Olson, Elizabeth Amber Fournier, Kaitlyn Yang, Diana Hanko and HPV Review Working Group

Vaccines 2026, 14(2), 156; https://doi.org/10.3390/vaccines14020156 - 5 Feb 2026

Abstract

The human papillomavirus (HPV) is the leading cause of cervical and oropharyngeal cancers. Vaccination can prevent over 90% of HPV-attributed cancers. Rural populations are less likely to initiate and complete HPV vaccinations than urban. The primary objective of this paper is to systematically [...] Read more.

The human papillomavirus (HPV) is the leading cause of cervical and oropharyngeal cancers. Vaccination can prevent over 90% of HPV-attributed cancers. Rural populations are less likely to initiate and complete HPV vaccinations than urban. The primary objective of this paper is to systematically examine the multilevel (child/youth, parent/caregiver, physician/team, healthcare organization, community, and policy) influences on HPV vaccine uptake in the rural US population. As a secondary aim, we seek to identify gaps in the research that could contribute to the development of more precise intervention approaches in this population. The study adds to the limited number of recent reviews on rural HPV vaccine uptake in the US. Method: We conducted a systematic search of published empirical studies over 13 years (2010–2023), resulting in 1657 publications. The following databases were searched: Medline (OVID), Embase, CINAHL, PsychInfo, Cochrane, Sociological Abstracts, and Scopus using pre-specified inclusion criteria. Two reviewers independently coded 101 full texts; discrepancies were resolved by a third reviewer. The primary outcome was HPV vaccine uptake. Results: Adolescents themselves were the most common foci of change. Barriers to rural HPV uptake included limited; vaccine awareness, access to vaccines for children vaccination sites, and primary care recommendations. Conclusions: Tailored interventions to rural parents/caregivers could increase uptake of the vaccine. Provider training increases HPV vaccine recommendations; programs should also be targeted to rural school nurses, pharmacists, and dental care providers. Linking primary care practices and public health dissemination strategies are key. Full article

(This article belongs to the Special Issue Acceptance and Hesitancy in Vaccine Uptake: 2nd Edition)

► Show Figures

Figure 1

18 pages, 2022 KB

Open AccessArticle

Exploring the Impact of Adjuvants on Vaccine Immunity Through Hematopoietic Cells

by Yuhyun Ji, Kavitha Bekkari, Mohammed Shardar, Geoffrey A. Walford, SamMoon Kim, Yaping Liu, Willis Read-Button, Kristina Tracy, Jennifer Kriss, Colleen Barr, Marissa Wolfle, Shailaa Kummar, Celia LaPorta, Rachel Graham, Lorenzo Chen, William James Smith, Kunal Bakshi, Nicholas Murgolo and Nicole Lea Sullivan

Vaccines 2026, 14(2), 155; https://doi.org/10.3390/vaccines14020155 - 5 Feb 2026

Abstract

Background/Objectives: Adjuvants, added to vaccines to enhance immune responses, are central to shaping the magnitude and durability of immunity, yet their precise mechanisms remain incompletely defined. This study evaluated how diverse adjuvant combinations influence HPV vaccine immunogenicity in non-human primates, with a particular [...] Read more.

Background/Objectives: Adjuvants, added to vaccines to enhance immune responses, are central to shaping the magnitude and durability of immunity, yet their precise mechanisms remain incompletely defined. This study evaluated how diverse adjuvant combinations influence HPV vaccine immunogenicity in non-human primates, with a particular focus on impacts on hematopoietic biology—megakaryocytes and platelets—and broader innate and adaptive pathways. Methods: Eight adjuvanted formulations, each incorporating distinct immunomodulatory components and delivery platforms, were compared against an alum-only control in non-human primates. Longitudinal antibody titers (HPV16-specific) were measured up to 54 weeks, and blood transcriptomes were profiled at Day 1 and Day 7 after both prime and boost doses to assess pathway-level enrichment and gene-expression patterns. Results: Several adjuvant combinations significantly increased antibody titers at 54 weeks compared with alum alone. Formulations containing cationic lipid or monophosphoryl lipid A (MPL) were associated with enhanced antibody responses. Early upregulation of immune-related genes across innate and adaptive pathways was also observed, with some combinations (e.g., inclusion of QS21 or ISCOMs) showing similar trends. Distinct group- and time-dependent transcriptional signatures were observed, with higher-responding formulations exhibiting stronger enrichment in pathogen-influenced signaling and cellular/humoral immune programs. Conclusions: Adjuvant selection and formulation strategy substantially modulate vaccine immunogenicity and early transcriptional programs, including innate, adaptive, and hematopoietic pathways. While individual adjuvants differentially regulate immune and platelet-associated genes, common pathway-level patterns emerge across formulations. These findings suggest candidate mechanisms for prolonged vaccine efficacy and provide actionable insights to guide rational adjuvant design for sustained immune protection. Full article

(This article belongs to the Special Issue Vaccines and Antibody-Based Therapeutics Against Infectious Disease)

► Show Figures

Figure 1

21 pages, 329 KB

Open AccessReview

Vaccination Strategies Against Respiratory Pathogens in the Adult Population: A Narrative Review

by Laura E. Sarabia, Elizabeth Williams, Kashmira Date, Estelle Méroc, Jennifer Eeuwijk, Bradford Gessner, Joseph Bresee, Alicia Fry and Elizabeth Begier

Vaccines 2026, 14(2), 154; https://doi.org/10.3390/vaccines14020154 - 4 Feb 2026

Abstract

Respiratory infections cause substantial morbidity and mortality in older adults and other at-risk adult populations. Despite the availability of effective vaccines, adult vaccination coverage remains suboptimal. This narrative review examines strategies designed to improve vaccine uptake among non-pregnant adults aged ≥18 years and [...] Read more.

Respiratory infections cause substantial morbidity and mortality in older adults and other at-risk adult populations. Despite the availability of effective vaccines, adult vaccination coverage remains suboptimal. This narrative review examines strategies designed to improve vaccine uptake among non-pregnant adults aged ≥18 years and inform future adult vaccination strategies. We conducted a targeted literature search using keywords for vaccination, respiratory diseases, strategy/program/implementation, and adults in PubMed database and CDC, WHO, and ECDC websites, between 2014 and 2024. A snowball search of literature reviews and key references was also performed to identify additional relevant studies. Eligible publications focused on vaccination strategies against influenza, COVID-19, and pneumococcal disease targeting non-pregnant adults (≥18 years). We categorized the strategies by intervention type to describe their influence on vaccination campaigns and vaccine uptake/coverage. We included 45 publications, encompassing strategies focused on individual decision-making, healthcare system functions, and national policy. Educational and awareness interventions (such as healthcare worker/provider recommendations during consultation, phone calls, letters, text messages, and social media outreach) reportedly raised vaccination rates. Access-related factors, including convenient vaccination sites and free or subsidized vaccines, were reported to be important factors in improving coverage in underserved communities. Within healthcare settings, strategies such as continuous vaccine provider training and workflow/process optimization were shown to enhance vaccination delivery. At the local or national policy levels, legislation governing program targets shaped immunization efforts and facilitated collaborations and partnerships to expand campaign reach. The findings may inform policymakers and public health/immunization practitioners in designing context-specific immunization initiatives that effectively reach adult populations. Full article

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

14 pages, 627 KB

Open AccessArticle

Improving Vaccine Knowledge Among Adolescents: A Pre–Post School-Based Educational Intervention in Southern Italy

by Vincenza Sansone, Gaia D’Antonio, Grazia Miraglia del Giudice, Francesco Napolitano and Gabriella Di Giuseppe

Vaccines 2026, 14(2), 153; https://doi.org/10.3390/vaccines14020153 - 4 Feb 2026

Abstract

Background/Objectives: Vaccination coverage among adolescents remains below the recommended target, highlighting the need for effective educational strategies to improve vaccine knowledge. This study aimed to assess baseline knowledge of vaccines and immune mechanisms among adolescents and to evaluate whether a school-based educational [...] Read more.

Background/Objectives: Vaccination coverage among adolescents remains below the recommended target, highlighting the need for effective educational strategies to improve vaccine knowledge. This study aimed to assess baseline knowledge of vaccines and immune mechanisms among adolescents and to evaluate whether a school-based educational intervention can improve knowledge related to vaccination. Methods: A prospective quasi-experimental pre–post study was conducted between 1 February 2025 and 1 June 2025 among adolescents aged 14–19 years attending high schools in Southern Italy. The intervention was based on the e-Bug educational module and delivered by trained nurses through interactive lessons, gamification, and guided discussions. Vaccine-related knowledge was assessed using a questionnaire administered before and after the intervention. Changes in knowledge scores were analyzed using paired statistical tests, and the effect size was estimated. A stepwise multivariate linear regression model was employed to identify factors associated with post-intervention test scores, with statistical significance set as p ≤ 0.05. Results: Among 386 participants, the majority were female (74.2%), the average age was 15.8, and 15% reported a chronic medical condition. Knowledge gaps were observed at baseline, particularly regarding the items on recommended adolescent vaccinations (37.4%), the definition of innate immunity (25.6%), and the mechanism of vaccines’ action (51%). After the intervention, all the items showed an improvement in correct answers, statistically significant for 5 of the 7 analyzed items (r = 0.364, p < 0.001). The most pronounced improvement was in the awareness of age-specific recommended vaccines (61.2%). The multivariate linear regression analysis showed that those with higher pre-intervention test scores, those who had parents with chronic medical conditions, those whose fathers worked, and those willing to participate in similar future interventions were more likely to achieve higher post-intervention test scores. Conclusions: School-based interventions may represent an effective strategy for enhancing adolescents’ knowledge related to vaccination, but further studies with control groups and long-term follow-up are needed to confirm effectiveness. Full article

(This article belongs to the Special Issue Acceptance and Hesitancy in Vaccine Uptake: 2nd Edition)

► Show Figures

Figure 1

13 pages, 500 KB

Open AccessArticle

Evaluation of the MenACWY Vaccination Catch-Up Campaign Among Adolescents in Madrid: Coverage, Trends, and Determinants

by Pablo Estrella-Porter, Amaya Sánchez-Gómez, María Dolores Lasheras Carbajo, Patricia Guillem Sáiz, Carmen Sáiz-Sánchez and Juan José Carreras

Vaccines 2026, 14(2), 152; https://doi.org/10.3390/vaccines14020152 - 4 Feb 2026

Abstract

Background: Invasive meningococcal disease (IMD) caused by Neisseria meningitidis remains a major public health concern due to its severity, lethality, and long-term sequelae. To address the rise in serogroups W and Y in Spain, the Community of Madrid implemented a catch-up campaign [...] Read more.

Background: Invasive meningococcal disease (IMD) caused by Neisseria meningitidis remains a major public health concern due to its severity, lethality, and long-term sequelae. To address the rise in serogroups W and Y in Spain, the Community of Madrid implemented a catch-up campaign in 2019–2021, targeting adolescents (ages 13–18) alongside routine tetravalent meningococcus vaccine (MenACWY) at age 12. This study evaluated MenACWY catch-up vaccination uptake in routine practice by describing vaccine coverage, temporal trends, and associated factors in adolescents born between 2001 and 2006. Methods: A population-based cross-sectional study was conducted using data from the Community of Madrid’s vaccination registry (SISPAL Vacunas). Vaccination coverage was calculated for adolescents with at least one recorded MenACWY dose from age 10 onwards. Temporal trends were analyzed by birth cohort and calendar time, and multivariable logistic regression models were used to identify factors associated with vaccination uptake. Results: Among 424,059 adolescents, overall vaccination coverage by December 2021 was 63.8%, ranging from 54.4% to 78.2% across birth cohorts. Coverage was highest in the 2006 cohort, likely due to co-administration with the tetanus and diphtheria (Td) booster. A slightly higher uptake was observed among females and adolescents with chronic conditions, while foreign-born adolescents consistently showed lower coverage. COVID-19 disruptions led to temporal variability, with sharp declines during lockdowns and partial recoveries thereafter, with persistent sociodemographic differences in uptake. Conclusions: By December 2021, coverage was incomplete, with marked variability across birth cohorts. Higher uptake was observed when vaccination was integrated into routine visits, while persistent sociodemographic disparities remained evident. These observational findings are consistent with the programmatic value of combined catch-up and routine strategies and the need for targeted actions to ensure equitable MenACWY coverage. Full article

(This article belongs to the Special Issue Advance Public Health Through Vaccination: 2nd Edition)

► Show Figures

Figure 1

15 pages, 4847 KB

Open AccessArticle

A Novel Inactivated Vaccine Based on an Emerging PEDV GIIc Variant Provides Cross-Protection Against Heterologous GII Strains

by Jingjing Xu, Ningning Fu, Zimin Liu, Mengli Chen, Guijun Ma, Hehai Li, Jianghui Wang, Bo Yin, Zhen Zhang and Feifei Diao

Vaccines 2026, 14(2), 151; https://doi.org/10.3390/vaccines14020151 - 3 Feb 2026

Abstract

Background/Objectives: Porcine epidemic diarrhea virus (PEDV), particularly the emerging GII genotype, poses a severe threat to the swine industry in affected regions, primarily in Asia. Current vaccines based on classical strains often provide limited cross-protection against these heterogeneous variants, though it should be [...] Read more.

Background/Objectives: Porcine epidemic diarrhea virus (PEDV), particularly the emerging GII genotype, poses a severe threat to the swine industry in affected regions, primarily in Asia. Current vaccines based on classical strains often provide limited cross-protection against these heterogeneous variants, though it should be noted that these vaccines are primarily designed to induce maternal immunity in sows. The objective of this study was to develop a novel inactivated vaccine using an emerging PEDV GIIc variant and evaluate its immunogenicity and cross-protective efficacy against heterologous strains. Methods: A novel PEDV strain, designated PEDV-HeN2024, was isolated from clinical samples and identified through cell culture, immunofluorescence assay (IFA), genetic sequencing, and phylogenetic analysis. An inactivated vaccine was prepared by emulsifying the purified virus with ISA 201 VG adjuvant (1:1, v/v). Immunogenicity was assessed in piglets by measuring virus-neutralizing antibody titers and PEDV-specific IgG levels. Cross-protective efficacy was evaluated through in vitro neutralization assays and in vivo challenge studies with homologous GIIc and heterologous GIIa and GIIb strains. Results: The isolated PEDV-HeN2024 strain demonstrated pathogenicity, causing severe diarrhea and 100% mortality in PEDV-naïve neonatal piglets. Sera from vaccinated animals showed potent cross-neutralizing activity against homologous GIIc, as well as heterologous GIIa and GIIb strains. In challenge studies, vaccinated piglets were significantly protected against clinical disease, showing no diarrhea or viral shedding, and maintained normal intestinal architecture. Conclusions: The inactivated vaccine developed from the emerging PEDV GIIc variant elicits robust humoral immunity and provides cross-protection against prevalent heterologous GII strains. These findings highlight its potential as a promising spectrum vaccine candidate for controlling PEDV outbreaks. This study underscores the importance of using recently circulating strains for vaccine development to overcome the limitations of current vaccines. Full article

(This article belongs to the Special Issue Vaccine Development for Swine Viral Pathogens)

19 pages, 452 KB

Open AccessArticle

Vaccine Perceptions Outweigh Emotional Flow in Predicting HPV Vaccination Intentions Among Gen Z College Students

by Christopher Hominski and Carolyn A. Lin

Vaccines 2026, 14(2), 150; https://doi.org/10.3390/vaccines14020150 - 3 Feb 2026

Abstract

Background/Objectives: HPV vaccination rates among U.S. young adults remain unchanged at 47% since 2019. Barriers including misinformation, vaccine hesitancy, and stigma surrounding HPV’s long-standing association with sexually transmitted infections have limited widespread acceptance among the male population. This experimental study explores how prevention [...] Read more.

Background/Objectives: HPV vaccination rates among U.S. young adults remain unchanged at 47% since 2019. Barriers including misinformation, vaccine hesitancy, and stigma surrounding HPV’s long-standing association with sexually transmitted infections have limited widespread acceptance among the male population. This experimental study explores how prevention messages incorporating an emotional flow element may influence vaccination intention. It also examines whether vaccination status may differentiate pre-exposure risk-taking tendencies and vaccine perceptions—as well as post-exposure HPV susceptibility, HPV severity, vaccine effectiveness, and emotional response—among young adults. Methods: A one-factor between-subjects experiment (including facts-only vs. facts→threat vs. facts→threat→hope conditions) was conducted online with a group of Gen Z college students at a U.S. university (N = 440). Results: ANCOVA results indicated that emotional flow embedded in the three message conditions did not result in significantly different emotional responses (across all participants) or vaccination intention among the unvaccinated participants. Whereas vaccinated participants reported greater perceived vaccine benefits, HPV susceptibility, HPV severity, and vaccine effectiveness, unvaccinated participants exhibited stronger emotional responses toward the facts→threat→hope message instead. Regression results revealed that vaccine perceptions, risk-taking tendencies, HPV susceptibility, and emotional response significantly predicted vaccination intention, in that order. TV advertising was identified as the leading HPV information source, followed by social media advertisements and recommendations from health professionals. Conclusions: These findings highlight that incorporating emotional flow may enhance message engagement among unvaccinated individuals. HPV campaigns should consider increasing positive vaccine perceptions, alleviating perceived threat of HPV, and eliciting positive emotional response toward vaccination acceptance and adoption. Full article

(This article belongs to the Section Human Papillomavirus Vaccines)

► Show Figures

Figure 1

15 pages, 2799 KB

Open AccessArticle

Timeliness of Routine Vaccination, Catch-Up Completion, and Immune Function in Chinese Children with Special Healthcare Needs: A Retrospective Cohort Study

by Yuyuan Zeng, Xihan Li, Yu Tian, Yuming Liu, Jianhong Wang, Qi An, Chuanyu Yang, Bo Zhou, Lili Zhang, Yangmu Huang and Lin Wang

Vaccines 2026, 14(2), 149; https://doi.org/10.3390/vaccines14020149 - 31 Jan 2026

Abstract

Background: Children with special healthcare needs (CSHCNs) face persistent barriers to timely immunization in China, but comparative evidence across disease groups and vaccines, and data on immune function, are limited. Methods: We conducted a retrospective cohort study linking electronic medical records, vaccination records, [...] Read more.

Background: Children with special healthcare needs (CSHCNs) face persistent barriers to timely immunization in China, but comparative evidence across disease groups and vaccines, and data on immune function, are limited. Methods: We conducted a retrospective cohort study linking electronic medical records, vaccination records, and a structured telephone and questionnaire follow-up. We estimated timely vaccination by National Immunization Program (NIP) dose definitions, assessed catch-up completion at follow-up, and compared cellular/humoral/complement immune indices with published pediatric reference ranges. Group differences used ANOVA/Kruskal–Wallis and chi-square (χ²)/Fisher’s exact tests with Bonferroni correction. Results: Timely vaccination was lower than the national healthy child benchmarks for all NIP vaccines (all p < 0.001); the Japanese encephalitis virus (JE; 24.0%) and measles-containing vaccine (MCV; 25.9%) had the lowest timely completion. A subset of CSHCNs did not receive recommended catch-up vaccinations, primarily due to persistent caregivers’ concern and point of vaccination (POV) staff’s hesitancy. Delays clustered in neonatal/perinatal disorders for Bacillus Calmette–Guérin (BCG) and hepatitis B vaccine, dose 1 (HepB1). Catch-up completion was highest for hepatitis B vaccine, dose 3 (HepB3) (86.3%) and BCG (81.8%), and lowest for the diphtheria and tetanus vaccine (DT) (49.4%); MCV2 completion was particularly low in hematological diseases. Immunoglobulin A (IgA) and immunoglobulin G (IgG) concentrations were significantly lower in neonatal/perinatal disorders and infectious disease groups versus neurological and immune disorder groups (p < 0.05). No severe adverse events were reported after catch-up. Conclusions: CSHCNs in China face substantial barriers to timely NIP immunization. Timeliness and catch-up vary substantially by vaccine and underlying condition; neonatal/perinatal disorders contribute disproportionately to early-life delays. Disease-specific guidance, strengthened POV–specialist clinic coordination, immunological monitoring, and supportive policies could improve the vaccination coverage and effectiveness in this vulnerable population. Full article

(This article belongs to the Special Issue Vaccines and Vaccine Preventable Diseases)

17 pages, 473 KB

Open AccessSystematic Review

HPV Exposure in the Gynecological Practice: Time to Call It an Occupational Disease? A Systematic Review of the Literature and ESGO Experts’ Opinion

by Hasan Volkan Ege, Bilal Esat Temiz, Mihaela Grigore, Laura Burney Ellis, Sarah J. Bowden, Belen Lopez-Cavanillas, Mario Preti, Ignacio Zapardiel, Elmar Joura, Murat Gültekin and Maria Kyrgiou

Vaccines 2026, 14(2), 148; https://doi.org/10.3390/vaccines14020148 - 31 Jan 2026

Abstract

Background/Objectives: Persistent human papillomavirus (HPV) infection can lead to malignancies of the cervix, vulva, vagina, penis, anus, and oropharynx. The increasing incidence of HPV-related head and neck cancers has raised concerns regarding potential occupational exposure and transmission risks among healthcare workers. This study [...] Read more.

Background/Objectives: Persistent human papillomavirus (HPV) infection can lead to malignancies of the cervix, vulva, vagina, penis, anus, and oropharynx. The increasing incidence of HPV-related head and neck cancers has raised concerns regarding potential occupational exposure and transmission risks among healthcare workers. This study aimed to systematically evaluate the evidence on occupational HPV transmission in healthcare settings. Methods: A systematic review of the literature was conducted using three electronic databases (PubMed, Scopus, and Web of Science) from inception to August 2025, following PRISMA 2020 guidelines. A total of 34 studies met the inclusion criteria and were included in the review. Expert opinions and practical recommendations from members of the European Society of Gynaecological Oncology (ESGO) Prevention Committee were included to support interpretation of the results. Results: The available literature on occupational HPV transmission was limited, with a paucity of high-quality studies. Nevertheless, existing data suggest a potential occupational risk, particularly during aerosol or smoke-generating procedures performed for cervical intraepithelial neoplasia or cervical cancer. Several studies reported the detection of HPV DNA in surgical smoke or on instruments used during such procedures, indicating possible exposure among healthcare workers. Conclusions: Although current evidence is insufficient to definitively classify HPV infection as an occupational disease, available data indicate a potential exposure risk for healthcare workers involved in HPV-related procedures. Preventive measures, like personal protective equipment, should be emphasized. HPV vaccination has been recommended by some professional societies for healthcare workers performing gynecological procedures, though further research is needed to evaluate vaccine efficacy beyond the standard age range and its cost-effectiveness in this context. Full article

(This article belongs to the Special Issue Role of Human Papillomavirus Vaccines in Cervical and Vulvo-Vaginal Diseases)

► Show Figures

Figure 1

14 pages, 1253 KB

Open AccessArticle

Statistical Modelling of Waning Immunity After Shanchol™ Vaccination: A Prospective Cohort Study

by Samuel Bosomprah, Fraser Liswaniso, Bernard Phiri, Mwelwa Chibuye, Charlie C. Luchen, Harriet Ng’ombe, Kennedy Chibesa, Dennis Ngosa, Mutinta Muchimba, Amanda K. Debes, Roma Chilengi, David A. Sack and Caroline C. Chisenga

Vaccines 2026, 14(2), 147; https://doi.org/10.3390/vaccines14020147 - 30 Jan 2026

Abstract

Introduction: Cholera remains a major public health threat in endemic settings, and oral cholera vaccine (Shanchol™) campaigns are increasingly used amid constrained global supply. However, practical decisions on revaccination require clearer, setting-specific estimates of how rapidly vaccine-induced vibriocidal antibodies peak and wane. [...] Read more.

Introduction: Cholera remains a major public health threat in endemic settings, and oral cholera vaccine (Shanchol™) campaigns are increasingly used amid constrained global supply. However, practical decisions on revaccination require clearer, setting-specific estimates of how rapidly vaccine-induced vibriocidal antibodies peak and wane. Methods: We conducted a prospective cohort kinetics analysis in Lukanga Swamps (Central Province, Zambia), enrolling adults (18–65 years) stratified by prior Shanchol™ exposure (0, 1, or 2 previous doses). All participants received two Shanchol™ doses 14 days apart, with serum collected at baseline and days 14, 28, 60, and 90 (end of follow-up). Ogawa and Inaba vibriocidal titres were measured using a complement-based assay and analysed on the log10 scale. Serotype-specific mixed-effects models with natural cubic splines for time (knots: 14, 28, 60 days) assessed trajectories by prior-dose strata, adjusting for age, sex, and HIV status. Peak timing and post-peak half-life were derived from model-based predictions with participant-level bootstrap CIs (1000 replications). Results: The analysis included 225 participants: 68 (30.2%) with zero prior doses, 89 (39.6%) with one, and 68 (30.2%) with two; median age was 33 years (IQR 25–49), 56.4% were female, and 19.2% were HIV-positive. Modelled titres for both serotypes rose steeply after vaccination, peaking around day 36–37 across prior-dose strata. Ogawa titres reached half of peak by about day 73–78, corresponding to post-peak half-lives of 37–41 days; Inaba declined more slowly with half-lives of 42–46 days. Confidence intervals overlapped across prior-dose strata, indicating minimal differences by vaccination history. Conclusions: In this cholera-endemic adult population, Shanchol™ induced vibriocidal responses that peaked at ~5 weeks and waned over the following 5–7 weeks, with broadly similar kinetics regardless of prior vaccination and slightly slower decay for Inaba than Ogawa. These parameters can inform booster timing in hotspot settings. Full article

(This article belongs to the Section Vaccines, Clinical Advancement, and Associated Immunology)

► Show Figures

Figure 1

17 pages, 1201 KB

Open AccessArticle

Immunogenicity and Safety of the ExPEC9V Escherichia coli Vaccine Co-Administered with a High-Dose Influenza Vaccine in Older Adults: A Placebo-Controlled, Randomized, Phase 3 Study

by Isabel Leroux-Roels, Tracey A. Day, Sofie Deleu, Chelsea McLean, Oscar Go, Todd A. Davies, Jeroen N. Stoop, Monika Peeters, Maria G. Pau, Bart Spiessens, Michal Sarnecki and Keira A. Cohen

Vaccines 2026, 14(2), 146; https://doi.org/10.3390/vaccines14020146 - 30 Jan 2026

Abstract

Background: ExPEC9V is a 9-valent vaccine candidate designed to prevent invasive Escherichia coli disease, a life-threatening condition occurring when extraintestinal pathogenic E. coli (ExPEC) invade sterile sites. We evaluated immunogenicity and safety when ExPEC9V was co-administered with high-dose (HD) quadrivalent seasonal influenza vaccine. [...] Read more.

Background: ExPEC9V is a 9-valent vaccine candidate designed to prevent invasive Escherichia coli disease, a life-threatening condition occurring when extraintestinal pathogenic E. coli (ExPEC) invade sterile sites. We evaluated immunogenicity and safety when ExPEC9V was co-administered with high-dose (HD) quadrivalent seasonal influenza vaccine. Methods: This Phase 3, double-blind, placebo-controlled study (NCT06134804) randomized 959 adults (≥65 years) to receive co-administration of ExPEC9V and HD quadrivalent seasonal influenza vaccine (CoAd) or each vaccine alone, 29 days apart (Control). Co-primary objectives were non-inferiority of co-administration versus separate administration following predefined criteria based on influenza strain-specific hemagglutination inhibition (HAI) antibody titers and ExPEC9V O-serotype binding antibody levels (multiplex electrochemiluminescence-based immunoassay), 29 days post vaccination. Reactogenicity and safety were assessed. Results: Co-administration of ExPEC9V with HD influenza vaccine demonstrated non-inferiority (upper bound of 2-sided 95% confidence interval [CI] < 1.5 for HAI geometric mean ratio [Control/CoAd]) for all influenza strains. Non-inferiority for ExPEC9V O-serotype antibody levels was not demonstrated (upper bound 95% CI > 1.5). One of nine serotypes met the non-inferiority criterion; eight did not, with four narrowly failing to meet the non-inferiority criterion. ExPEC9V immunogenicity was similar regardless of urinary tract infection history. ExPEC9V was safe and well tolerated, with no serious adverse events related to ExPEC9V. Reactogenicity rate was higher with co-administration. Conclusions: Co-administration of ExPEC9V with HD influenza vaccine met non-inferiority criteria of humoral immune responses for influenza antigens, but not for ExPEC9V O-serotype antigens. ExPEC9V, administered alone or with HD influenza vaccine, was safe and well tolerated, with an acceptable reactogenicity profile. Full article

(This article belongs to the Section Vaccines, Clinical Advancement, and Associated Immunology)

► Show Figures

Figure 1

10 pages, 639 KB

Open AccessArticle

Correlation Analysis Between HLA Polymorphisms and Immune Response to Hepatitis B Vaccine in Children with Acute Lymphoblastic Leukemia

by Rui Zhang, Tian Yang, Yijin Gao, Hua Zhang, Yi Fei, Laibao Yang and Pengfei Deng

Vaccines 2026, 14(2), 145; https://doi.org/10.3390/vaccines14020145 - 30 Jan 2026

Abstract

Background: The human leukocyte antigen (HLA) is crucial for antigen presentation and vaccine efficacy. This study examined the association between HLA polymorphisms and the immune response to hepatitis B vaccination in children with acute lymphoblastic leukemia (ALL). Methods: 101 pediatric ALL patients at [...] Read more.

Background: The human leukocyte antigen (HLA) is crucial for antigen presentation and vaccine efficacy. This study examined the association between HLA polymorphisms and the immune response to hepatitis B vaccination in children with acute lymphoblastic leukemia (ALL). Methods: 101 pediatric ALL patients at Shanghai Children’s Medical Center affiliated with Shanghai Jiaotong University School of Medicine who tested negative for hepatitis B surface antibody (anti-HBs) and were not infected with hepatitis B received three doses of the hepatitis B vaccine. Anti-HBs titers were measured before and after vaccination. Participants were divided into high- and low-response groups based on post-vaccination anti-HBs titers. Sequence-specific primer polymerase chain reaction (PCR-SSP) was used to genotype HLA-A, -B, -Cw, -DRB1, and -DQB1 alleles. Results: Pre-vaccination anti-HBs titers were 3.38 ± 2.97 mIU/mL, and the post-vaccination seroconversion rate was 100% with mean titers of 429.61 ± 303.13 mIU/mL (p < 0.001). Following immunization, the low-response group (11.88%) had an anti-HBs titer of 56.47 ± 28.38 mIU/mL, while the high-response group (88.12%) had an anti-HBs titer of 479.93 ± 287.70 mIU/mL. There were significant differences in allele frequencies of B*3501 and Cw*0303 between the two response groups (p < 0.05). Binary logistic regression analysis showed that the B*3501 allele was negatively correlated with the anti-HBs response level (p < 0.05). Conclusions: HLA-B*3501 may be associated with lower antibody response levels in children with ALL who completed the full hepatitis B vaccination series. All these children demonstrated protection against the hepatitis B virus (HBV). We will subsequently validate the association between HLA-B*3501 and the level of hepatitis B vaccine immune response in children with ALL through expanding the sample size or conducting a multicenter study. Full article

(This article belongs to the Section Hepatitis Virus Vaccines)

► Show Figures

Figure 1

14 pages, 277 KB

Open AccessArticle

Global Health Preparedness Frameworks and Recombinant Vaccine Platforms: A Public Health Perspective on Regulations and System Readiness

by Luigi Russo, Leonardo Villani, Roberto Ieraci and Walter Ricciardi

Vaccines 2026, 14(2), 144; https://doi.org/10.3390/vaccines14020144 - 30 Jan 2026

Abstract

Background/objectives. Emerging viral diseases represent an increasing threat to global health security, driven by environmental change, globalization, and intensified human–animal–environment interactions. The COVID-19 pandemic exposed critical weaknesses in preparedness systems but also demonstrated the transformative potential of recombinant vaccine technologies, which enable rapid, [...] Read more.

Background/objectives. Emerging viral diseases represent an increasing threat to global health security, driven by environmental change, globalization, and intensified human–animal–environment interactions. The COVID-19 pandemic exposed critical weaknesses in preparedness systems but also demonstrated the transformative potential of recombinant vaccine technologies, which enable rapid, scalable, and safe responses to novel pathogens. We aim to examine the role of recombinant vaccine platforms in the management of emerging viral diseases, emphasizing their contribution to health system preparedness and exploring strategies for their integration into preparedness frameworks. Methods. We synthesized the current evidence on recombinant vaccine platforms (viral vector, protein subunit, DNA, and mRNA) through a targeted review of the scientific literature, regulatory documents, and global health policy reports. Drawing from experiences like COVID-19 (mRNA vaccines) and Ebola (rVSV-ZEBOV), we analyzed the advantages, challenges, and lessons from initiatives such as the CEPI, BARDA, HERA, and WHO frameworks. Results. Recombinant vaccine platforms offer significant advantages for epidemic preparedness through rapid adaptability, standardized production, and strong safety profiles. Nonetheless, challenges remain in manufacturing scalability, cold-chain logistics, regulatory harmonization, and equitable global access. Global initiatives such as the CEPI, WHO-led programs, BARDA, and regional manufacturing networks exemplify this collaborative approach, while regulatory mechanisms have proven to be essential to timely vaccine deployment. Conclusions. Recombinant vaccines have redefined preparedness by coupling scientific innovation with operational agility. Strengthening global coordination, regional production capacity, and public trust is essential to ensure that technological progress translates into equitable and effective public health impacts. Full article

(This article belongs to the Special Issue Developing Recombinant Vaccines and Immunotherapy Strategies for Emerging Viral Diseases)

3 pages, 436 KB

Open AccessCorrection

Correction: Zhang et al. African Swine Fever Virus MGF 360-2L Disrupts Host Antiviral Immunity Based on Transcriptomic Analysis. Vaccines 2025, 13, 918

by Taoqing Zhang, Xiaodong Qin, Sujie Dong, Yuanshu Wu, Xiaolan Qi, Jingjing Ren, Yuan Wen, Zhengwang Shi, Tao Feng, Bingjie Sun, Changying Wang and Haixue Zheng

Vaccines 2026, 14(2), 143; https://doi.org/10.3390/vaccines14020143 - 30 Jan 2026

Abstract

In the original publication [...] Full article

► Show Figures

Figure 4

17 pages, 1683 KB

Open AccessArticle

Development and Evaluation of Immunoprotective Efficacy of Membrane Protein Vaccine Against Scuticociliatosis

by Qingmeihui Sun, Bingchen Wu, Yaoqi Ao, Xiaoyu Meng, Xiaohang Wang and Ruijun Li

Vaccines 2026, 14(2), 142; https://doi.org/10.3390/vaccines14020142 - 29 Jan 2026

Abstract

Objective: To develop a novel and efficient vaccine for controlling scuticociliatosis in turbot (Scophthalmus maximus), this study targeted the parasitic ciliate Pseudocohnilembus persalinus for membrane protein vaccine preparation. Methods: The immunoprotective efficacy and underlying molecular mechanisms of the vaccine were systematically [...] Read more.

Objective: To develop a novel and efficient vaccine for controlling scuticociliatosis in turbot (Scophthalmus maximus), this study targeted the parasitic ciliate Pseudocohnilembus persalinus for membrane protein vaccine preparation. Methods: The immunoprotective efficacy and underlying molecular mechanisms of the vaccine were systematically evaluated through immunization–challenge experiments, immune parameter detection, and transcriptomic analysis. Results: Results showed that the serum IgM level in turbot immunized with the membrane protein vaccine reached its peak one week after the second immunization, which was significantly higher than that in the control group and the whole-cell protein vaccine group (p < 0.05). Additionally, the activities of serum peroxidase (POD), total superoxide dismutase (T-SOD), acetylcholinesterase (ACH), and lysozyme (LZM) were significantly enhanced (p < 0.05). At 24 h and 48 h post-challenge, the relative parasite reduction rates at the wound sites in the membrane protein vaccine group were 87.79% and 74.17%, respectively. Transcriptomic analysis revealed 1063 differentially expressed genes (DEGs) in the spleen tissue of turbot immunized with the membrane protein vaccine, including 734 upregulated and 329 downregulated genes. These DEGs were significantly enriched in pathways such as glycine, serine and threonine metabolism and one carbon pool by folate, which are involved in immune responses by regulating immune cell proliferation, antioxidant defense, and immune substance synthesis. Conclusions: This study successfully developed a P. persalinus membrane protein vaccine with excellent immunoprotective efficacy and elucidated its molecular mechanisms of protection. It provides a novel vaccine candidate for the green control of turbot scuticociliatosis and offers a theoretical basis and technical support for the development of fish parasite subunit vaccines. Full article

(This article belongs to the Special Issue Novel Vaccine Designs to Enhance the Engagement of Innate and Adaptive Immunity)

► Show Figures

Figure 1

11 pages, 250 KB

Open AccessArticle

Impact of Adjuvant Nonavalent HPV Vaccination on Viral Clearance in HPV-Positive Women With and Without Excisional Treatment: A Retrospective Cohort Study

by Ali Deniz Erkmen and Kevser Arkan

Vaccines 2026, 14(2), 141; https://doi.org/10.3390/vaccines14020141 - 29 Jan 2026

Abstract

Background: Persistent infection with high-risk human papillomavirus (HPV) is the key driver of cervical carcinogenesis and post-treatment recurrence. Although excisional treatment effectively removes dysplastic tissue, it does not directly target viral persistence. While HPV vaccination is well established in primary prevention, its potential [...] Read more.

Background: Persistent infection with high-risk human papillomavirus (HPV) is the key driver of cervical carcinogenesis and post-treatment recurrence. Although excisional treatment effectively removes dysplastic tissue, it does not directly target viral persistence. While HPV vaccination is well established in primary prevention, its potential role as an adjuvant strategy in HPV-positive women, particularly with respect to viral clearance, remains incompletely defined. Methods: This retrospective cohort study included HPV-positive women with at least 12 months of follow-up who were managed at a tertiary gynecology clinic. Patients were stratified according to HPV vaccination status with the nonavalent vaccine (Gardasil 9) and excisional treatment status with loop electrosurgical excision procedure (LEEP). HPV clearance at 12 months was defined as the primary outcome, while histological outcomes were evaluated as secondary and independent endpoints. Analyses were performed in the overall cohort and stratified by LEEP status. Multivariable logistic regression was used to identify factors independently associated with HPV persistence, adjusting for baseline disease severity and clinical covariates. Results: A total of 935 HPV-positive women were included in the final analysis. Completion of the three-dose HPV vaccination schedule was associated with significantly higher HPV clearance rates at 12 months compared with no vaccination. This association was consistently observed in women who underwent LEEP as well as in those managed without excisional treatment. In multivariable analysis, HPV vaccination emerged as an independent protective factor against HPV persistence, whereas LEEP status itself was not independently associated with viral clearance after adjustment for baseline histological severity. Histological outcomes differed according to baseline disease severity and did not demonstrate a direct one-to-one relationship with HPV clearance. Conclusions: Adjuvant vaccination with the nonavalent HPV vaccine is independently associated with increased HPV clearance in HPV-positive women at 1-year follow-up, irrespective of excisional treatment status. HPV clearance and histological regression represent related but distinct biological processes and should be evaluated as independent outcomes. These findings support a broader role for HPV vaccination beyond primary prevention and suggest potential clinical benefit of vaccination as an adjunctive strategy in the management of HPV-positive women. Full article

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

16 pages, 256 KB

Open AccessReview

New HPV Vaccines on the Market and Future Trends: A State-of-the-Art Review

by Utku Akgör, Bilal Esat Temiz, Murat Cengiz, Hasan Volkan Ege, Elmar Joura and Murat Gültekin

Vaccines 2026, 14(2), 140; https://doi.org/10.3390/vaccines14020140 - 29 Jan 2026

Abstract

Next-generation human papillomavirus (HPV) vaccines encompass newly licensed and emerging formulations that employ alternative production platforms, expanded valency, or novel antigenic targets beyond conventional L1-based vaccines. These vaccines aim to address affordability challenges, supply limitations, and suboptimal vaccination coverage, particularly in low- and [...] Read more.

Next-generation human papillomavirus (HPV) vaccines encompass newly licensed and emerging formulations that employ alternative production platforms, expanded valency, or novel antigenic targets beyond conventional L1-based vaccines. These vaccines aim to address affordability challenges, supply limitations, and suboptimal vaccination coverage, particularly in low- and middle-income countries. This review aggregates current clinical, immunological, and programme-related evidence on newly licensed vaccines, including the World Health Organization (WHO)-prequalified bivalent formulations (Cecolin^® and Walrinvax^®), the quadrivalent Cervavac^®, and the Escherichia coli-derived nonavalent Cecolin 9^®, which received national licensure in 2025. Additionally, emerging high-valency candidates in Phase I–III trials—9-valent, 11-valent, and 14-valent formulations—are critically assessed. Clinical trials demonstrate that next-generation HPV vaccines provide robust protection; for example, Cecolin^® showed 100% efficacy against HPV-16/18-associated high-grade squamous intraepithelial lesions (HSIL) and up to 97.8% efficacy against persistent HPV infection, while Walrinvax^® demonstrated 78.6% protection against CIN2+ lesions. Cervavac^® showed non-inferior immunogenicity compared with established vaccines. While comparative analyses of efficacy, immunogenicity, and safety indicate that these vaccines are strong alternatives to established products, robust long-term effectiveness and real-world impact data remain essential before full clinical equivalence can be definitively established. Advances in L2-based platforms further aim to broaden cross-type protection, simplify manufacturing, and enable thermostable formulations, thereby enhancing applicability in resource-limited settings. Economic evaluations demonstrating favorable cost-effectiveness emphasize the essential role of next-generation vaccines in improving access and reducing inequity. Overall, innovations in valency, technology, and delivery strategies have the potential to significantly expand global HPV prevention coverage and accelerate progress toward cervical cancer elimination. Full article

(This article belongs to the Special Issue Role of Human Papillomavirus Vaccines in Cervical and Vulvo-Vaginal Diseases)

10 pages, 368 KB

Open AccessArticle

Rotavirus Vaccine Coverage and Surveillance of Adverse Events Following Immunization in a Birth Cohort of Children (2017–2023) in Suzhou, China

by Jinling Gao, Kunpeng Zhu, Lin Luan, Benfeng Zheng, Juan Xu, Yiheng Zhu, Xianquan Fan, Haitao Wang and Na Liu

Vaccines 2026, 14(2), 139; https://doi.org/10.3390/vaccines14020139 - 29 Jan 2026

Abstract

Objectives: To analyze the changes in the proportion of the rotavirus vaccine among children born in the 2017–2023 cohort and to assess the current status of rotavirus vaccination coverage in Suzhou, China. To monitor adverse events following immunization (AEFIs) so as to [...] Read more.

Objectives: To analyze the changes in the proportion of the rotavirus vaccine among children born in the 2017–2023 cohort and to assess the current status of rotavirus vaccination coverage in Suzhou, China. To monitor adverse events following immunization (AEFIs) so as to provide data for scientific guidance regarding the rotavirus vaccine. Methods: The basic information of children born between 1 January 2017 and 31 December 2023 in Suzhou and information regarding rotavirus vaccination were collected through the child module of Jiangsu Province Vaccination Integrated Service Management Information System. Information on AEFI case reports was collected from the AEFI monitoring system of the China Information System for Disease Control and Prevention. Descriptive epidemiological methods were used to analyze the rotavirus vaccine characteristics and AEFI classification, and the Mann–Whitney U test was used for comparative analysis. Results: The proportion of children born in the 2017–2023 cohort who received the first dose of the rotavirus vaccine was 14.65%. The reassortant rotavirus vaccine, live, oral, pentavalent (RV5) proportion gradually increased, and the vaccine proportion of children in the 2023 birth cohort reached the highest. The peak age for rotavirus vaccination was between 2 and 8 months. A total of 49,507 children (99.88%) received the first dose of RV5 at the age of 6–12 weeks in this birth cohort, and there was a statistically significant difference in the median duration of the first dose of RV5 among children of different age groups (p < 0.001). A total of 89 cases of AEFIs were reported, and the reported incidence of AEFIs was 3.47/10,000 doses. Among them, 86 cases of general reactions were reported, with a reported incidence of 3.35/10,000 doses, and three cases of abnormal reactions were reported, with a reported incidence of 0.12/10,000 doses. Conclusions: The rotavirus vaccine proportion of children born in Suzhou from 2017 to 2023 was not high. The incidence of AEFI reports from the rotavirus vaccine is relatively low, indicating a favorable safety profile. Efforts should prioritize strengthening health education on rotavirus gastroenteritis to enhance public confidence in vaccination, thereby ensuring the effective prevention and control of rotavirus gastroenteritis. Full article

(This article belongs to the Special Issue Vaccine Efficacy and Disease Burden Evaluation)

► Show Figures

Figure 1

Journal Description

Vaccines

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI