Vaccine最新文献

{"title":"A novel hypothetical protein (SAUSA300_1684) confers excellent protection against multi-drug-resistant Staphylococcus aureus infection in the murine model","authors":"Pranaya M. Mishra ,&nbsp;Suman Chaudhary ,&nbsp;Ravi S. Manhas ,&nbsp;Sakshi R. Lokwani ,&nbsp;Diksha Sharma ,&nbsp;Dipak Dutta ,&nbsp;Manoj K. Baranwal ,&nbsp;Ravi P.N. Mishra","doi":"10.1016/j.vaccine.2026.128220","DOIUrl":"10.1016/j.vaccine.2026.128220","url":null,"abstract":"<div><div><em>Staphylococcus aureus</em> is a leading cause of nosocomial infections, including sepsis, bacteraemia, pneumonia, and endocarditis, and continues to pose a major public health challenge due to escalating multidrug resistance and the absence of an effective vaccine. To address this unmet clinical need, we employed a machine learning–guided reverse vaccinology approach to systematically interrogate the <em>S. aureus</em> proteome for novel vaccine antigens. This strategy led to the identification of eight previously uncharacterized hypothetical proteins with predicted immunogenic properties. Among these, SAUSA300_1684 protein (designated IMTS8) was prioritized for detailed translational evaluation. IMTS8 was found to be highly conserved across major clinical <em>S. aureus</em> lineages and expressed throughout growth phases of the methicillin-resistant strain USA300-FPR3757. Analysis of the surface-shaved proteome revealed that IMTS8 is likely exposed on the bacterial surface, a finding further substantiated by immunofluorescence microscopy. Immunization of mice with recombinant adjuvanted IMTS8 elicited strong antigen-specific IgG responses and conferred near-complete protection in a murine staphylococcal infection model. Collectively, these findings identify IMTS8 as a promising protein subunit vaccine candidate for the prevention of multidrug-resistant <em>Staphylococcus aureus</em> infections. In addition, this study highlights the translational utility of machine learning–based reverse vaccinology as an effective platform for accelerating antigen discovery against antimicrobial-resistant bacterial pathogens.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128220"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term immunogenicity of alternative HPV vaccine schedules and the effect of an additional dose given three to five years post-primary vaccination","authors":"Chantal Sauvageau ,&nbsp;Iulia G. Ionescu ,&nbsp;Manale Ouakki ,&nbsp;Gitika Panicker ,&nbsp;Vladimir Gilca ,&nbsp;Elizabeth R. Unger ,&nbsp;Marie-Hélène Mayrand","doi":"10.1016/j.vaccine.2026.128287","DOIUrl":"10.1016/j.vaccine.2026.128287","url":null,"abstract":"<div><div>We assessed antibody persistence and the impact of an additional dose administered 42–60 months after initial vaccination. Girls initially vaccinated at ages 9–10 with two doses of quadrivalent HPV vaccine participated in two randomized trials: The 0-6-42HPV study which compared a quadrivalent and bivalent additional dose given at 42 months; The 0-6-60ICI-VPH study compared no additional dose to a quadrivalent dose at 60 months. HPV16/18 antibody detection and geometric mean concentrations (GMCs) were assessed (M9ELISA). Overall, 526 girls provided a blood sample. All had detectable HPV16/18 antibodies 10 years post-initial vaccination. An additional dose at 42 versus 60 months led to similar GMCs, both with higher immune responses compared to 2-dose group participants. Compared to the quadrivalent, the bivalent induced significantly higher HPV18 GMCs, which has unknown clinical significance. Two-dose schedule and delayed quadrivalent or bivalent additional doses are highly immunogenic, supporting long-term immunogenicity of alternative and mixed vaccination schedules.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128287"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146128080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incidence and bacterial etiology of acute otitis media in children in the pneumococcal conjugate vaccine era: A systematic literature review and meta-analysis","authors":"Mejbah Uddin Bhuiyan ,&nbsp;Gustavo Hernandez-Suarez ,&nbsp;Tamara Pilishvili ,&nbsp;Ben Mayer ,&nbsp;Victoria Abbing-Karahagopian","doi":"10.1016/j.vaccine.2026.128270","DOIUrl":"10.1016/j.vaccine.2026.128270","url":null,"abstract":"<div><h3>Background</h3><div>This systematic literature review (SLR) evaluated the incidence and bacterial etiology of acute otitis media (AOM) in children.</div></div><div><h3>Methods</h3><div>Epidemiological studies in English reporting on AOM incidence (published 2008–2023) or the distribution of <em>Streptococcus pneumoniae</em> (Spn) including serotypes, <em>Haemophilus influenzae</em> (Hi), and <em>Moraxella catarrhalis</em> (Mcat) in children (&lt;18 years) with AOM (published 2010–2023) were identified from Embase, MEDLINE, LILACS, and SciELO databases. Random-effect models were used to determine the pooled AOM incidence rates (IR), pooled prevalence of each bacterium and individual serotypes/strains, and the corresponding 95% confidence intervals. When feasible, the estimates were stratified by age group, geographical location, and pneumococcal vaccination status. Heterogeneity was assessed by the <em>I</em>^<em>2</em> statistic.</div></div><div><h3>Findings</h3><div>The SLR identified 37 publications reporting on AOM incidence, of which 25 were included in the meta-analysis, and 34 publications reporting on prevalence of bacterial pathogens in middle ear fluid. AOM IRs (per 100 person-years) were 18.77 in ≤2-year-olds, 10.39 in &gt;2 to ≤5-year-olds, and &lt;3 in children aged &gt;5 years. In ≤2-year-olds, AOM IR was 16.07 among those who received a pneumococcal conjugate vaccine (PCV) and 34.26 among those who did not. Among ≤2-year-olds, Hi contributed to 31.81% of AOM cases, followed by 19.35% for Spn, and 3.00% for Mcat. Across all ages, frequently reported Spn serotypes among Spn-AOM cases were 3 (10.81%), 19F (10.65%), 19A (10.43%), 23A (4.60%), 35B (4.38%), and 21 (3.23%) whereas 78.2% of Hi-AOM cases were caused by non-typeable Hi (NTHi).</div></div><div><h3>Interpretation</h3><div>A substantial AOM burden in children remains during the PCV era, with disproportionately higher incidence among children ≤2 years old. Select PCV- and non-PCV pneumococcal serotypes and NTHi have contributed significantly to the AOM burden. Vaccines offering improved protection against remaining PCV serotypes, emerging pneumococcal serotypes, and NTHi are needed to reduce the existing AOM burden in children.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128270"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary safety evaluation of a diphtheria, tetanus, acellular component pertussis, Sabin inactivated poliovirus and Haemophilus influenzae type b combination vaccine (DTacP-sIPV/Hib)","authors":"Lukui Cai ,&nbsp;Yixian Fu ,&nbsp;Jingyan Li ,&nbsp;Xiaoyu Wang ,&nbsp;Yan Ma ,&nbsp;Qin Gu ,&nbsp;Qiuyan Ji ,&nbsp;Guoyang Liao ,&nbsp;Shengjie Ouyang ,&nbsp;Hongbo Chen ,&nbsp;Lujie Yang ,&nbsp;Mingqing Wang ,&nbsp;Wenzhu Hu ,&nbsp;Hongwei Liao ,&nbsp;Guang Ji ,&nbsp;Jiana Wen ,&nbsp;Na Gao ,&nbsp;Lin Ping ,&nbsp;Yuting Fu ,&nbsp;Han Chu ,&nbsp;Jingsi Yang","doi":"10.1016/j.vaccine.2026.128277","DOIUrl":"10.1016/j.vaccine.2026.128277","url":null,"abstract":"<div><div>The DTacP-sIPV/Hib combination vaccine is designed to replace the separate administration of diphtheria, tetanus, acellular pertussis, poliomyelitis, and <em>Haemophilus influenzae</em> type b vaccines. By incorporating Sabin strain inactivated poliovirus, DTacP-sIPV/Hib offers advantages in biosafety and manufacturing cost. This study provides a preliminary evaluation of the preclinical safety of a novel DTacP-sIPV/Hib combination vaccine in three animal models.</div><div>Sprague-Dawley rats were randomly assigned to receive either DTacP-sIPV/Hib or saline by intramuscular injection and were monitored for 14 days for local reactions, body weight, and food intake, followed by necropsy and histopathological examination. Guinea pigs were allocated to negative control, positive control or vaccine groups and sensitized by three intramuscular injections on alternate days; animals were subsequently challenged and observed for allergic reactions. Japanese white rabbits were used in a bilateral self-controlled design, receiving vaccine in one quadriceps and saline in the contralateral side, with macroscopic and histopathological evaluation at 48 h and 16 days post-injection.</div><div>The candidate DTacP-sIPV/Hib vaccine induced only mild, transient, and reversible local reactions in SD rats and rabbits, indicating acceptable local tolerability under the conditions tested. No detectable effects on body weight or food intake were observed in rats, and no allergic reactions were induced in guinea pigs, suggesting no apparent systemic safety signals in these models. Overall, these findings provide supportive nonclinical safety evidence for the candidate DTacP-sIPV/Hib vaccine and may inform the design and risk assessment of subsequent clinical studies.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128277"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-dose mSEB–mi3 nanoparticle vaccine elicits robust humoral immunity and protects mice against SEB intoxication and MRSA infection","authors":"Ziyi Liao ,&nbsp;Meilin Wu ,&nbsp;Yuan Chen ,&nbsp;Zifan Zhu ,&nbsp;Yuhang Li ,&nbsp;Qijun Mei ,&nbsp;Bo Huang ,&nbsp;Xin Cheng ,&nbsp;Yi Zhang ,&nbsp;Hao Zeng ,&nbsp;Daiyuan Ma ,&nbsp;Jiang Gu","doi":"10.1016/j.vaccine.2026.128245","DOIUrl":"10.1016/j.vaccine.2026.128245","url":null,"abstract":"<div><div><em>Staphylococcus aureus</em> (SA) causes severe hospital-and community-acquired infections, yet no vaccine is licensed. Staphylococcal enterotoxin B (SEB) is a conserved virulence factor and a key target for vaccine development. However, SEB protein subunit vaccines often suffer from limited immunogenicity. Self-assembling mi3 nanoparticles provide an efficient antigen display platform and could overcome subunit limitations. We engineered a nanoparticle vaccine by displaying detoxified mutant SEB (L45R, Y89A, Y94A) on mi3 scaffold (mSEB-mi3). Biophysical characterization confirmed stable, uniform particles with efficient antigen conjugation. We compared adjuvants (ALPO4, CpG ODN1018, AS01, MF59) in mice, assessing dendritic cell (DC) uptake/maturation, humoral responses, and protection against in SEB intoxication and methicillin-resistant SA (MRSA) ST59 infection models, alongside safety evaluations. We successfully produced a uniform and stable mSEB-mi3 nanoparticle. The mSEB-mi3 markedly improves dendritic-cell uptake and maturation and drives rapid, high, and durable antibody responses with balanced IgG1/IgG2a isotypes. Functionally, a single intramuscular dose confers strong protection against both SEB intoxication and SA ST59 challenge. In addition, safety profiles were acceptable across hematology, chemistry, cytotoxicity, and histopathology. These results identify mSEB-mi3 as a promising and scalable nanoparticle vaccine against SA and SEB toxin. The findings support further studies of durability, strain breadth, and translational development.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128245"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors related to immunization uptake among the hill tribe and stateless children in northern Thailand: A mixed methods study","authors":"Tawatchai Apidechkul ,&nbsp;Mary C. Smith Fawzi ,&nbsp;Kim Alyson Wilson","doi":"10.1016/j.vaccine.2026.128254","DOIUrl":"10.1016/j.vaccine.2026.128254","url":null,"abstract":"<div><div>Immunization is a significant health care tool to protect against crisis-related threats to human health, particularly in underserved populations such as hill tribes and stateless people in Thailand. A mixed method aimed to identify the barriers to and facilitators of the use of vaccines among five-year-old hill tribe and stateless children living in the border areas of northern Thailand and Myanmar. Logistic regression was used to detect associations in the quantitative data, and content analysis was used for qualitative data analysis. A total of 188 cases and 188 controls were analyzed; 54.0 % were boys, and 54.3 % were from the Akha tribe. Children without a birth certificate (AOR = 8.57), children who received a vaccine at a provincial/district hospital (AOR = 14.76), private hospital or clinic (AOR = 7.29), children living with ≥3 other children aged 6–12 years (AOR = 3.61), children living with mothers who were non-Thai citizens (AOR = 4.40), children living with mothers who had not attended school (AOR = 4.08), children living with a primary caregiver who was Yao (AOR = 4.58) or Lisu (AOR = 2.94), children living with a Christian or Muslim primary caregiver (AOR = 2.76), and children living with elderly individuals who brought them for vaccinations (AOR = 2.30) had greater odds of having incomplete vaccination than children with the opposite characteristics. Communication challenges, different perspectives on vaccines among different generations, stages of citizenship, mobility, disasters, and a lack of effective health policies were detected as barriers to vaccination. While seeking a new life for younger generations was a facilitator for vaccination. A public health policy for vaccine services without a Thai citizenship requirement should be implemented to increase coverage for hill tribe and stateless children living in the border areas of Thailand and Myanmar.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128254"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146004698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibody responses to SARS-CoV-2 vaccine in nursing home residents support a Bi-annual update schedule","authors":"Alexandra N. Paxitzis ,&nbsp;Oladayo A. Oyebanji ,&nbsp;Olajide J. Olagunju ,&nbsp;Debbie Keresztesy ,&nbsp;Mike Payne ,&nbsp;Vaishnavi Ragavapuram ,&nbsp;Nicholas Sundheimer ,&nbsp;Ellen See ,&nbsp;Dennis Wilk ,&nbsp;Yi Cao ,&nbsp;Yasin Abul ,&nbsp;Clare Nugent ,&nbsp;Evan Dickerson ,&nbsp;Tiffany Wallace ,&nbsp;Laurel Holland ,&nbsp;Aman Nanda ,&nbsp;Walther M. Pfeifer ,&nbsp;Alejandro B. Balazs ,&nbsp;Christopher L. King ,&nbsp;Stefan Gravenstein ,&nbsp;Jürgen Bosch","doi":"10.1016/j.vaccine.2026.128240","DOIUrl":"10.1016/j.vaccine.2026.128240","url":null,"abstract":"<div><h3>Background</h3><div>The COVID-19 pandemic has greatly affected nursing home residents (NHRs), a vulnerable group with high rates of illness and death. While vaccination is essential for reducing infections and severe outcomes in the short term, it is important to understand how long antibody levels and neutralizing activity last. This understanding will help us create effective public health strategies for the long term. According to current CDC guidelines, individuals over 65 should receive a booster dose six months after their previous vaccination.</div></div><div><h3>Methods</h3><div>This observational retrospective cohort study analyzed post-vaccination serum from samples with up to 400 days of follow-up from 697 NHRs and 127 healthcare workers (HCWs) across Northeast Ohio and Rhode Island. Analyses were conducted to model decay rates of neutralizing and binding antibody titers and the impact of previous exposures to SARS-CoV-2 on these decay rates.</div></div><div><h3>Results</h3><div>Results indicate that NHRs show Wuhan and Omicron BA.4/5 neutralizing and binding antibody titers diminish significantly from 2 weeks to 12 months post-vaccination. NHRs with prior infection show higher peak antibody titers and slower decay than those naive to infection. Antibody levels after vaccination for infection-naive NHR lagged HCW and NHR with prior infection, but then decayed at a similar rate.</div></div><div><h3>Conclusion</h3><div>The immunologic findings in this cohort of NHR align with the existing real-world clinical effectiveness data in older individuals and support the CDC recommendation of a bi-annual vaccination to reduce severe COVID-19 outcomes in persons age 65 and older.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128240"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bromelain-cleaved hemagglutinin production from cell culture-derived influenza viruses enhances vaccine potency quantification by single radial immunodiffusion assay","authors":"Ohseok Jeong ,&nbsp;Wooyoung Choi ,&nbsp;Hyebin Ahn ,&nbsp;Seonghyun Lee ,&nbsp;Yong Wook Park ,&nbsp;Hun Kim ,&nbsp;Jae-Hwan Nam","doi":"10.1016/j.vaccine.2026.128235","DOIUrl":"10.1016/j.vaccine.2026.128235","url":null,"abstract":"<div><div>Single Radial Immunodiffusion (SRID) assay remains the gold standard for determining influenza vaccine potency. Accurate SRID assays require high-purity antigens and strain-specific antisera that closely match circulating viruses. However, mutations in influenza viruses propagated in traditional egg-based systems affect antigenicity and assay accuracy. Therefore, we optimized bromelain-cleaved hemagglutinin (BHA) production from cell culture-derived influenza viruses, specifically targeting A/H3N2 and B/Victoria lineage strains. We employed a sequential enzymatic digestion strategy and successfully generated highly purified BHA with improved antigen yield and minimal neuraminidase contamination. The resulting antisera demonstrated strong, strain-specific reactivity. Subsequent SRID assays confirmed that homologous antigen–antiserum pairs derived from cell culture-derived materials provided significantly more accurate hemagglutinin quantification than the heterologous or egg-derived combinations. These findings highlight the need to match antigen and antiserum sources. Further, cell culture-derived reagents could be used to enhance assay reliability, advancing influenza vaccine standardization and quality control in cell-based vaccine production. By demonstrating the importance of antigen–antiserum matching and optimizing BHA production from cell culture-derived influenza viruses, this study establishes a practical foundation for improving the reliability of SRID-based potency testing and advancing the standardization of next-generation influenza vaccines.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128235"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Persistent measles immunization gaps in LMICs: Insights from the 2024 revision of the WHO/UNICEF estimates of National Immunization Coverage","authors":"Moses Mwale","doi":"10.1016/j.vaccine.2026.128298","DOIUrl":"10.1016/j.vaccine.2026.128298","url":null,"abstract":"<div><h3>Background</h3><div>Measles remains a leading vaccine-preventable killer in low- and middle-income countries (LMICs). Using the WHO/UNICEF Estimates of National Immunization Coverage (WUENIC) 2024 revisions, this article assesses measles-containing vaccine first-dose (MCV1) and second-dose (MCV2) coverage trends, inequities, and priority groups for targeted action.</div></div><div><h3>Methods</h3><div>Data from 2019 to 2024 for 137 LMICs were analysed using descriptive statistics; Welch's <em>t</em>-tests and Wilcoxon rank-sum tests to compare fragile versus non-fragile states; Gini coefficients for inequality; k-means clustering (k = 4) on coverage, MCV1-to-MCV2 dropout, change, unvaccinated counts, and fragility; and bounded linear models to project MCV1 to 2030.</div></div><div><h3>Results</h3><div>In 2024, mean MCV1 coverage was 79.2% (95% CI: 76.8–81.6)—below the 95% threshold—with fragile LMICs at 68.5% versus 87.4% in non-fragile LMICs (difference − 18.1 percentage points; <em>p</em> &lt; 0.001). MCV2 gaps were larger (−26.9 percentage points; p &lt; 0.001). DTP1-based zero-dose prevalence was 20.8%, with 15.6 million children unvaccinated for MCV1 and 22.4 million for MCV2; West and Central Africa accounted for 7.2 million MCV1-unvaccinated (46.2%). Inequality rose (Gini 0.22 → 0.25, 2019–2024). Projections indicate MCV1 of 84.2% by 2030, with fragile LMICs off-track. Clustering identified four profiles: (1) very low coverage, high dropout, high fragility (22 countries); (2) high coverage, low dropout (44); (3) low coverage, severe dropout (31); and (4) low coverage, moderate dropout (40), each implying distinct priorities (conflict-adapted SIAs; sustaining gains; follow-up campaigns; expanding first-dose access).</div></div><div><h3>Conclusions</h3><div>Persistent and widening measles immunization gaps—especially in fragile settings—threaten IA2030's 90% coverage targets. Pairing the 2024 WUENIC revision with fragility-sensitive clustering and bounded projections provides a practical framework to prioritize equity-focused funding and operational strategies where need is greatest.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128298"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of duck hepatitis A virus type 1 attenuated vaccine E23-SP80 and its protective efficacy evaluation against DHAV-1 infection in ducks","authors":"Jiajia Li,&nbsp;Phoo Eikari Kyaw,&nbsp;Chanjuan Tan,&nbsp;Kairui Wen,&nbsp;Jiabin Zhang,&nbsp;Yichen Tian,&nbsp;Dengfei Feng,&nbsp;Wenjian Liu,&nbsp;Shuhui Liu,&nbsp;Suquan Song,&nbsp;Liping Yan","doi":"10.1016/j.vaccine.2026.128258","DOIUrl":"10.1016/j.vaccine.2026.128258","url":null,"abstract":"<div><div>Duck Hepatitis A Virus type 1 (DHAV-1) is a highly pathogenic virus that causes severe mortality in ducklings and results in substantial economic losses to the global duck industry. Live-attenuated DHAV vaccine remains one of the most effective strategies for controlling this disease. We developed a safe and effective live attenuated vaccine candidate E23-SP80 adapted to specific-pathogen-free (SPF) chicken embryos by serial passage of a field isolate. The E23-SP80 exhibited an adaptive growth capacity in SPF chicken embryos with a viral titer of 10^7.25 ELD₅₀/0.2 mL and lost its pathogenicity in 2-day-old Cherry Valley ducklings. The vaccine strain maintained its attenuation and showed no virulence reversion after back propagation into 2-day-old ducklings for five rounds. An immunizing dose of only 10^3.0 ELD₅₀ of E23-SP80 could provide 100% protection against challenge with lethal parental DHAV-1 strain. After a single intramuscular vaccination, virus-neutralizing antibody titers exceeded 9 log₂ from 7 to 28 days post-vaccination and the titers were markedly higher than those of a commercial vaccine. Genomic analysis of E23-SP9 and E23-SP80 revealed fifteen amino acid substitutions, most of which were located in VP1 and 2A2 proteins, and the hypervariable region of VP1 (T180I and D193N) might contribute to attenuation. These results suggest that E23-SP80 strain is a promising commercial vaccine candidate for the prevention and control of DHAV-1 infection.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128258"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}