Vaccine[JOURNAL]
Sun
200 papers
SARS-CoV-2 Ancestral and Omicron variant immunity in Australian children in 2023, a seroprevalence study.
Koirala A, Prasad SA, Tjiam MC … +33 more , Britton PN, Tedja C, Downes M, Skowno J, Wadia UD, Blyth CC, Crawford NW, Marshall HS, Clark JE, Francis JR, Carr JP, Bartlett A, McMullan BJ, Carey E, Chung S, Davidson A, von Ungern-Sternberg BS, Archer PL, Burgoyne LL, Waugh EB, Ong MM, Tansil S, Thornton RB, McMinn A, Hunter G, D'Angelo N, Finucane C, Francis LA, Dougherty S, Naing Z, Wood N, Richmond P, Macartney K
Vaccine · 2026 Jul · PMID 42143953 · Publisher ↗
BACKGROUND: The emergence of the SARS-CoV-2 Omicron variant in late 2021 led to widespread infection in Australian children, many unvaccinated. The breadth and magnitude of antibody responses to SARS-CoV-2 variant infect...
BACKGROUND: The emergence of the SARS-CoV-2 Omicron variant in late 2021 led to widespread infection in Australian children, many unvaccinated. The breadth and magnitude of antibody responses to SARS-CoV-2 variant infections and vaccination in children remain incompletely understood. We aimed to estimate seroprevalence against SARS-CoV-2 spike (S) and nucleocapsid (N) antigens and explore antibody kinetics, focusing on Omicron subvariants. METHODS: Between 1 November and 7 December 2023, blood samples were collected from children aged 0-16 years undergoing anaesthetic procedures at eight tertiary paediatric hospitals. SARS-CoV-2 antibodies to ancestral spike and nucleocapsid protein and eight Omicron spike proteins were tested. Crude and adjusted seroprevalence estimates derived using multilevel regression and poststratification were obtained. Geometric mean concentrations (GMCs) were calculated for S- and N- antibodies and analysed by age and vaccination status. RESULTS: Of 1065 children tested, adjusted seroprevalence to ancestral S-antibody was 93.1% (95% CrI, 91.4-94.5) and N-antibody was 79.8% (77.1-82.2). Seroprevalence was high across jurisdictions, socioeconomic quintiles, and remoteness categories, and lowest in infants aged 6-11 months (S-antibody, 69.5% [95% CrI: 54.7-81.8] and N-antibody 35.2% [95% CrI: 21.1-49.1]). GMCs to nine distinct SARS-CoV-2 spike variants were uniformly high and increased with age and vaccination. GMC to ancestral S-antibody was highest in two-dose vaccinated children while unvaccinated children aged >1 year had highest GMC to Omicron BA.5. DISCUSSION: By late 2023, nearly all participants had serological evidence of SARS-CoV-2 infection, with highest concentrations to ancestral strain and Omicron BA.5 spike proteins, suggesting variant-specific immune imprinting.
Rare adverse events after COVID-19 vaccination among Swedish older adults-evidence from a nationwide register-based study.
Xu Y, Nyberg F, Marking U … +3 more , Gisslén M, Wastesson JW, Johnell K
Vaccine · 2026 Jul · PMID 42142527 · Publisher ↗
INTRODUCTION: COVID-19 vaccinations have saved millions of lives, particularly among older adults. Rare potential adverse events have been reported in case reports, but risks among older adults remain unclear. This study...
INTRODUCTION: COVID-19 vaccinations have saved millions of lives, particularly among older adults. Rare potential adverse events have been reported in case reports, but risks among older adults remain unclear. This study assessed risks of selected potential adverse events in this population. METHODS: We included more than 2 million Swedish adults ≥65y in a nationwide register-based cohort. Post-vaccination risks were assessed for herpes zoster (HZ), encephalitis, myelitis and encephalomyelitis, multiple sclerosis (MS), myasthenia gravis, cranial nerve palsy, sudden sensorineural hearing loss (SSNHL), postinfectious arthritis and polymyalgia rheumatica (PMR) in several risk windows (1-30, 31-60, and 61-180 days) after each vaccine dose. Hazard ratios (HRs) with 95% confidence intervals (95%CIs) compared with unvaccinated were estimated by Cox regression adjusted for potential confounders. Sensitivity analyses included adding primary health care (PHC) visits, and applying analysis-specific 5-year disease-free wash-out periods. RESULTS: No increased HRs were observed for most outcomes. SSNHL showed increased HRs within 180 days after each dose [1.60 (95%CI 1.15-2.24); 1.43 (1.03-1.99); 1.61 (1.05-2.46) for dose 1, 2 and 3], with similar estimates across all three risk windows. Increased HRs were also seen for PMR after dose 2 [1.14 (1.04-1.24)] and dose 3 [1.16 (1.03-1.30)], with higher HRs during later time windows. HZ showed increased HRs in the sensitivity analysis with PHC visits, [1.19 (1.07-1.31); 1.31 (1.19-1.43); 1.42 (1.26-1.60) for dose 1, 2 and 3]. MS showed reduced risk after dose 3 in the sensitivity analysis with longer wash-out (targeting incident MS), but not in the main analysis (potential relapses included). CONCLUSIONS: COVID-19 vaccines are generally safe in older adults, with very low incidence of the potential rare adverse events assessed. Slightly increased relative risks for SSNHL, PMR and HZ were observed, but these findings do not alter the overall benefit-risk profile of COVID-19 vaccination in older adults.
Systemic BCG administration induces transcription factor signature in CD4 T cells that cooperates with IL-12 signaling to drive antiviral Th1 differentiation.
Wang R, Zhao Y, Yang J … +7 more , Luo R, Sun W, Zhang M, Liu X, Hou Y, Cao P, Li E
Vaccine · 2026 Jul · PMID 42142526 · Publisher ↗
Mycobacterium bovis bacillus Calmette-Guerin (BCG) is a form of live attenuated M. bovis-based vaccine used to prevent tuberculosis and other mycobacterial infections. BCG immunization also provides cross-protection agai...
Mycobacterium bovis bacillus Calmette-Guerin (BCG) is a form of live attenuated M. bovis-based vaccine used to prevent tuberculosis and other mycobacterial infections. BCG immunization also provides cross-protection against a broad range of viral pathogens. Recent studies show that a coordinated induction of innate and adaptive immune responses is involved, though the mechanisms are less defined. To investigate the cross-protection of BCG against virus infection, we used a mouse model of respiratory syncytial virus (RSV) infection and demonstrated that systemic administration of live BCG altered chromatin accessibility for transcriptional factor expression favoring Th1 response. Specifically, BCG-IV immunization protected mice against RSV infection. BCG immunization caused metabolic reprogramming in monocytes and neutrophils and innate immune response, leading to IL12/IL12R-mediated naïve CD4 T cell differentiation to the Th1 cell population. Integrated analysis of chromatin openness and transcriptomic data revealed that BCG administration upregulated transcription factors including interferon regulatory factors (IRF1) and signal transducer and activator of transcription (STAT1 and STAT2), a signature for interferon signaling and antiviral response. This work highlights a crucial role for the adaptive immune response in mediating naïve CD4 T cell differentiation and cross-protection through epigenetic remodeling for antiviral response against pathogens in an antigen-agnostic manner.
Quality and methodological heterogeneity of COVID-19 vaccine safety studies focusing on the myocarditis safety signal: A systematic review, meta-analysis and meta-regression.
Trang TPH, Bazelier MT, Klungel OH … +1 more , Bots SH
Vaccine · 2026 Jul · PMID 42142525 · Publisher ↗
BACKGROUND: The risk of myocarditis following COVID-19 vaccines has been widely investigated, yielding highly variable effect estimates. It remains unclear how much of this variation can be explained by methodological di...
BACKGROUND: The risk of myocarditis following COVID-19 vaccines has been widely investigated, yielding highly variable effect estimates. It remains unclear how much of this variation can be explained by methodological differences and study quality. This study aimed to evaluate the methodology of observational studies on myocarditis risk post-COVID-19 vaccination and identify sources of heterogeneity. METHODS: We systematically searched PubMed and EMBASE for observational studies reporting relative risks of myocarditis after COVID-19 vaccination published between December 2020 and October 2023. Risk of Bias (RoB) was assessed using the ROBINS-I tool. Meta-analysis and multivariable meta-regression were conducted for studies addressing comparable population-intervention-comparator-outcome (PICO) questions. RESULTS: We included 30 studies, comprising 35 design-specific analyses. We identified considerable variability in design elements including risk window length (7-288 days), reference period timing (three different ways), and control for COVID-19 disease (five different approaches). Thirteen (37%) design-specific analyses had serious or critical overall RoB. We observed strongest heterogeneity between studies in general population for dose 2 of BNT162b2 and mRNA-1273 compared to unvaccinated individuals/reference period (I = 96%, prediction interval (PI) of relative risk 0.40-20.20; I = 92%, PI 1.23-88.63, respectively). Meta-regression for the former PICO indicated that after adjusting for age and sex, effect estimates of samples with 28-day risk window were 0.56 times (95% CI 0.43-0.72) lower than those with 7-day risk window, but its overall effect was not significant. The effect of study design, outcome definition, approaches to handle COVID-19 infection and overall RoB were not significant in the meta-regression. CONCLUSIONS: There is substantial variation in study design specifications and corresponding heterogeneity in reported effect estimates. Design choices like risk window length may explain some of this heterogeneity, although evidence remains inconclusive. Future vaccine safety studies should include sensitivity analyses to explore the effect of design choices on their findings.
Double proline- substituted porcine epidemic diarrhea virus full-length spike mRNA vaccine confers enhanced immunogenicity and protective efficacy compared to conventional inactivated vaccine.
Zeng L, Pan D, Huang Y … +14 more , Luo D, Zhang S, Lin C, Lin B, He Y, Shi X, Feng S, Qin Y, Yin Y, Chen Y, Wei Z, Huang W, Qian Z, Ouyang K
Vaccine · 2026 Jul · PMID 42142524 · Publisher ↗
Porcine epidemic diarrhea virus (PEDV) is a highly contagious pathogen causing near 100% mortality in neonatal piglets, posing a persistent threat to the global swine industry. In this study, we isolated a PEDV strain, 2...
Porcine epidemic diarrhea virus (PEDV) is a highly contagious pathogen causing near 100% mortality in neonatal piglets, posing a persistent threat to the global swine industry. In this study, we isolated a PEDV strain, 23GXNN-1 (genotype G2c), from an outbreak in Guangxi, China. Two mRNA vaccine candidates were developed: one encoding the wild-type spike (S) protein S-WT and another incorporating proline-stabilized mutations (S-2P, I1076P/L1077P). Evaluations in HEK293T cells and animal models (BALB/c mice, sows, and piglets) revealed that the S-2P LNP-mRNA vaccine induced superior immunogenicity compared to S-WT, generating robust humoral immunity (elevated IgG/IgA titers and neutralizing antibodies) and enhanced cellular immune responses. Notably, maternal immunization with S-2P conferred 100% survival in piglets challenged with virulent PEDV G2c via efficient passive transfer of antibodies through colostrum, outperforming commercial inactivated vaccines. While vaccines provide limited protection to gut microbiota diversity and intestinal barrier integrity during infection, maternally derived antibodies effectively reduce disease severity. This study not only identifies S-2P as a promising candidate for PEDV control, but also underscores the crucial role of maternal immunity in neonatal protection, advancing mRNA-based strategies against enteric coronaviruses.
Immunogenicity of 2 versus 3 dose HPV vaccination by HIV infection status in Eswatini.
Nuwagaba-Biribonwoha H, Lamb MR, Dlamini X … +11 more , Zerbe A, Anabwani-Richter FA, Zech JM, Hsu A, Mabuza N, Lukhele NM, Fayorsey R, Sahabo R, Nkambule R, El-Sadr WM, Abrams EJ
Vaccine · 2026 Jul · PMID 42142523 · Publisher ↗
BACKGROUND: There are limited immunogenicity data among people with HIV (PWH) following human papilloma virus (HPV) vaccination, particularly with fewer dose schedules. We compared immunogenicity of 9-valent HPV vaccine...
BACKGROUND: There are limited immunogenicity data among people with HIV (PWH) following human papilloma virus (HPV) vaccination, particularly with fewer dose schedules. We compared immunogenicity of 9-valent HPV vaccine (9vHPV) by HIV infection status in Eswatini. METHODS: In this multi-site, open-label, non-inferiority study, three PWH cohorts received 2-doses of 9vHPV at 0 and 6 months: 1) boys 9-14 years (n = 349); 2) girls 9-14 years (n = 352); 3) adolescent girls and young women (AGYW) 15-26 years (n = 350). A comparison cohort of AGYW without HIV received the reference standard 3-dose regimen at 0, 2 and 6 months. At 7 months, we measured HPV-6/11/16/18/31/33/45/52/58 antibodies by competitive Luminex Immunoassay. We assessed non-inferiority of anti-HPV geometric mean titer ratios (GMTR), lower-bound 95% confidence interval > 0.5, among PWH versus AGYW without HIV; and secondarily explored GMTRs by HIV viral load (VL) at baseline or 7 months. RESULTS: PWH 2-dose completion was high: 95% boys, 97% girls and 93% AGYW. Among AGYW without HIV, 95% received the second dose and 84% completed the 3-doses. GMTR of boys and girls with HIV were non-inferior to AGYW without HIV for all HPV subtypes: boys ranged from 0.74 (0.60, 0.90) for HPV-45 to 1.30 (1.08, 1.56) for HPV-58; girls ranged from 0.70 (0.58, 0.86) for HPV-45 to 1.32 (1.10, 1.58) for HPV-58. GMTR of AGYW with HIV were non-inferior to AGYW without HIV for all subtypes except HPV-45; ranging from 0.66 (0.54, 0.81) for HPV-18 to 0.95 (0.78, 1.14) for HPV-11, and (0.40, 0.60) for HPV-45. Among PWH with VL > 50 copies/mL, titers for all HPV sub-types were lower, and GMTRs were not non-inferior. CONCLUSION: We found overall non-inferior immunogenicity of 2-dose 9vHPV among PWH versus 3-doses in AGYW without HIV, but 2-dose immunogenicity among viremic PWH may be compromised. Resource-saving 2-dose vaccination is an appropriate option for PWH while sustaining their VL suppression. TRIAL REGISTRATION NUMBER: clinicaltrials.govNCT04982614.
Predicting Salmonella Typhi incidence using prevalence metrics from sentinel studies of community-onset bloodstream infections: a secondary analysis of observational data.
Hagedoorn NN, Murthy S, Marchello CS … +33 more , Williman J, Ahmmed F, Andrews JR, Basnyat B, Carter AS, Datta S, Dehraj IF, Doyle K, Garrett DO, Jacob J, Jeon H, John J, Khanam F, Lee J, Liu X, Marks F, Naga SR, Neuzil KM, Newton PN, Patel PD, Pollard AJ, Qadri F, Qamar FN, Roberts T, Seidman JC, Shakya M, Shrestha S, Tadesse BT, Tamrakar D, Vongsouvath M, Voysey M, Yousafzai MT, Crump JA
Vaccine · 2026 Jul · PMID 42142522 · Publisher ↗
BACKGROUND: Typhoid fever incidence estimates are central to policy decisions on vaccine introduction and investments in non-vaccine prevention and control but are often unavailable. We explored whether prevalence metric...
BACKGROUND: Typhoid fever incidence estimates are central to policy decisions on vaccine introduction and investments in non-vaccine prevention and control but are often unavailable. We explored whether prevalence metrics from sentinel studies of community-onset bloodstream infections could accurately predict local Salmonella enterica serovar Typhi (Salmonella Typhi) incidence. METHODS: Using a previous systematic review (January 2018-December 2024), we identified studies reporting both typhoid incidence and prevalence of community-onset bloodstream infections from sentinel sites. From authors, we requested data on blood culture isolates and analysed four metrics: (i) Salmonella Typhi prevalence among probable pathogens, (ii) Salmonella Typhi rank order, (iii) Salmonella Typhi to Escherichia coli ratio, and (iv) Salmonella Typhi to 'stably endemic' organisms ratio. Typhoid incidence was categorized as low (<10), medium (10-100) or high (>100) per 100,000 person-years. We used univariate ordinal regression to assess the association between each metric and typhoid incidence level. The model performance was evaluated by the c-statistic, sensitivity, and specificity. RESULTS: Analysis of 29 study sites (20 Africa, 9 Asia) yielded 4625 probable pathogens. The median (IQR) typhoid incidence was 140 (28-319) per 100,000 person-years. All metrics were associated with increased typhoid incidence level: for each 1% increase in Salmonella Typhi prevalence OR 1.07 (95%CI 1.02-1.15); for each unit increase in rank order OR 0.25 (95%CI 0.06-0.64); for each unit increase in the log Salmonella Typhi to E. coli ratio OR 2.88 (95%CI 1.48-7.39) for each unit increase in the log Salmonella Typhi to 'stably endemic' organisms ratio OR 3.74 (95%CI 1.80-10.7). A parsimonious model using Salmonella Typhi prevalence alone achieved c-statistics of 0.87 (0.58-0.97), 0.76 (0.51-0.91), and 0.88 (0.69-0.96) for low, medium, and high incidence, respectively. CONCLUSION: Sentinel prevalence metrics from bloodstream infections, particularly Salmonella Typhi prevalence among probable pathogens, could be useful for inferring local typhoid fever incidence where direct data are unavailable.
Instruments for measuring parents' vaccine hesitancy towards their children based on the COSMIN guidelines: A systematic review.
Cao T, Chen B, Chen S … +5 more , Liu H, Li Y, Ren X, Gao J, Hou C
Vaccine · 2026 Jul · PMID 42140092 · Publisher ↗
BACKGROUND: Parental vaccine hesitancy undermines immunization gains, leading to resurgent outbreaks and increased child mortality. Reliable assessment instruments are urgently needed to guide effective interventions and...
BACKGROUND: Parental vaccine hesitancy undermines immunization gains, leading to resurgent outbreaks and increased child mortality. Reliable assessment instruments are urgently needed to guide effective interventions and improve coverage. Despite multiple vaccine hesitancy assessment instruments, no systematic reviews have evaluated the measurement properties of these instruments against established methodological standards, limiting evidence-based selection. OBJECTIVE: To systematically evaluate the methodological quality and measurement properties of vaccine hesitancy assessment instruments for parents of 0-18 children, providing an evidence-based basis for selecting appropriate instruments. DESIGN: Measurement properties are systematically reviewed according to the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines. METHODS: Six electronic databases were systematically searched from inception until July 15, 2025. Methodological quality was assessed using the COSMIN Risk of Bias Checklist and measurement properties were synthesized according to the COSMIN criteria. A modified Grading, Recommendations, Assessment, Development, and Evaluation system was used to assess the certainty of evidence. RESULTS: Forty studies evaluating 31 vaccine hesitancy assessment instruments were included. Based on COSMIN evidence grading, the Malay version of the modified vaccine hesitancy scale (MVHS-M), the Vietnamese version of the parent attitudes about childhood vaccines survey (PACV-Viet), and the parental attitude scale towards vaccination (PASV) received Category A recommendation. The general vaccine hesitancy scale (GVHS), vaccination attitudes examination (VAX), vaccine acceptance instrument (VAI), and vaccine barriers assessment tool (VBAT) received Category C recommendation, while others were Category B recommendation. CONCLUSIONS: This systematic review identified MVHS-M, PACV-Viet, and PASV as effective tools for assessing vaccine hesitancy in parents, suitable for both research and clinical use. Future research should comprehensively assess their measurement properties, especially exploring measurement error and responsiveness. REGISTRATION: A protocol was registered on the PROSPERO (CRD420251070194).
A nanoparticle vaccine targeting glycoprotein D induces immune protection against pseudorabies virus.
Sun X, Liu R, Yang H … +6 more , Zhang Y, Hu W, Wang H, He H, Kong Z, Zhang G
Vaccine · 2026 Jul · PMID 42140091 · Publisher ↗
Pseudorabies virus (PRV) is a highly transmissible zoonotic pathogen that poses a serious threat to the swine industry and presents potential public health risks. In this study, we designed a tetrameric antigen targeting...
Pseudorabies virus (PRV) is a highly transmissible zoonotic pathogen that poses a serious threat to the swine industry and presents potential public health risks. In this study, we designed a tetrameric antigen targeting PRV glycoprotein D (gD) and constructed a nanoparticle vaccine by coupling fluorinated polyethylenimine (FPEI) with λ-carrageenan (λ-CGN). Results showed that gD-FPEI-λ-CGN exhibited favorable immunostimulatory in vitro. Comprehensive biosafety evaluations demonstrated that the nanoparticles showed negligible cytotoxicity and no observable histopathological damage in major mouse organs. Neutralization assays revealed that the vaccine prompted high levels of PRV-specific neutralizing antibodies. Furthermore, Enzyme-linked immunosorbent assay (ELISA) results showed that gD-FPEI-λ-CGN induced a Th1-biased cellular immune response in vivo. Upon PRV challenge, mice immunized with gD-FPEI-λ-CGN showed effective protection, resulting in reduced mortality. This study highlights a materials-based nanoparticle platform that integrates antigen multimerization and immune modulation, offering a promising strategy for PRV vaccine development.
Complete protection against lethal Nipah virus challenge by intranasal vaccination with bacteriophage T4 coupled with Nipah virus G or F protein.
Chen M, Zhang X, Yao Y … +13 more , Yu J, Li J, Peng Y, Gao G, Li L, Xue H, Li X, Liu H, Chen M, Wang W, Yang H, Qiu S, Wei H
Vaccine · 2026 Jul · PMID 42140090 · Publisher ↗
Nipah virus (NiV) is a highly lethal zoonotic pathogen, causing disease that can spread between animals and people with a mortality rate about 40% to 70%. No commercially approved vaccines or therapeutics are available....
Nipah virus (NiV) is a highly lethal zoonotic pathogen, causing disease that can spread between animals and people with a mortality rate about 40% to 70%. No commercially approved vaccines or therapeutics are available. In this study, novel NiV vaccines targeting the attachment glycoprotein (G) or fusion glycoprotein (F) of NiV were developed utilizing bacteriophage T4 as a carrier platform. The immune effects induced in mice by intranasal immunization (i.n.) and intramuscular injection (i.m.) show that i.n. immunization with bacteriophage T4 coupled with Nipah virus G or F protein can not only stimulate humoral immunity and cellular immunity, but also induce excellent mucosal immune responses. Complete protection against lethal NiV challenge was achieved in Syrian hamsters after intranasal immunization with either T4-G, T4-F, or the mixture of T4-G and T4-F (1:1). Due to its safety and modular versatility, the bacteriophage T4 carrier system presents a promising strategy for developing vaccines against NiV and other viruses.
Dropout from the pentavalent vaccine series among children aged 12-23 months in the Central African Republic: prevalence, associated factors, and caregiver-reported barriers.
Ishoso DK, Fandema E, Hoff NA … +19 more , Nkamba DM, Merritt S, Halbrook M, de Dieu Longo J, Mafuta Musalu E, Kasonga Ngindu JB, Bangelesa F, Stahley K, Fangbilette JLK, Djekou C, Matkoss FE, Bobo ES, Zanga-Goumet HE, Patrice FM, El Mourid A, Somse P, Manirakiza A, Rimoin AW, Kaba DK
Vaccine · 2026 Jul · PMID 42140089 · Publisher ↗
BACKGROUND: Routine childhood immunization in the Central African Republic (CAR) is inconsistent due to reasons including political instability and service disruptions. This study assessed dropout between the first and t...
BACKGROUND: Routine childhood immunization in the Central African Republic (CAR) is inconsistent due to reasons including political instability and service disruptions. This study assessed dropout between the first and third pentavalent doses among children aged 12-23 months who had received Penta 1, identified associated risk factors, and explored caregiver-reported barriers. Additional dropout indicators within this cohort-specifically from Penta 1 to Penta2, from Penta2 to Penta 3, and from Penta 3 to measles-were also examined to support contextual interpretation. METHODS: We conducted a cross-sectional household survey from December 2023 to March 2024, based on a nationally representative sample covering all seven health regions and 35 districts of the CAR. This secondary analysis focused on dropout between key vaccine doses among children aged 12-23 months and was conducted using Stata 17. Data were collected through structured interviews with caregivers, with vaccination status primarily verified using home-based records; when unavailable, health facility data or caregiver recall were used. Survey-weighted logistic regression models were used to identify factors associated with vaccine dropout. Reasons for non-vaccination were analyzed thematically using the adapted WHO BeSD framework. RESULTS: Among 4121 children aged 12-23 months who had received Penta 1, the national prevalence of dropout between the first and third doses of the pentavalent vaccine was 34.5% (95% CI: 32.4-36.6). Additionally, among these children, we observed 17.0% dropout from Penta 1 to Penta2, 17.5% from Penta2 to Penta 3, and 15.8% from Penta 3 to the measles-containing vaccine. Higher odds of dropout between Penta 1 and Penta 3 were associated with households lacking television (aOR: 2.98; 95% CI:1.88-4.72), absence of birth registration (aOR:1.56; 95% CI:1.26-1.94) and caregivers engaged in agricultural activities (aOR:3.45; 95% CI:1.85-6.44). Primary reported reasons for non-vaccination included access barriers such as distance to the vaccination site (30.9%) and vaccine stockouts (14.0%), contextual and household challenges like caregiver time constraints (29.7%) and family-related problems (10.8%), information gaps including lack of knowledge about the vaccination schedule (27.3%), and motivational concerns such as fear of side effects (10.4%) and distrust in vaccines (2.9%). CONCLUSION: In the CAR, 34.5% of children who receive the first pentavalent dose fail to complete the three dose vaccination series. Improving follow-up and adapting services to overcome local barriers is essential to increase rates of complete immunization.
The cost-effectiveness of vaccination against COVID-19 in at-risk populations and older adults in the United Kingdom: Projections using a dynamic transmission model.
Kohli M, Maschio M, Lee A … +6 more , Kissler S, Carroll S, van de Velde N, Beck E, Balogh O, Joshi K
Vaccine · 2026 Jul · PMID 42140088 · Publisher ↗
OBJECTIVE: This study estimates the potential clinical impact and cost-effectiveness of an Autumn COVID-19 vaccination campaign in the United Kingdom (UK) using a variant-adapted mRNA-1273 vaccine in those aged ≥65 years...
OBJECTIVE: This study estimates the potential clinical impact and cost-effectiveness of an Autumn COVID-19 vaccination campaign in the United Kingdom (UK) using a variant-adapted mRNA-1273 vaccine in those aged ≥65 years and those aged 6 months-64 years at high risk (base case population) of severe outcomes, as well as the effect of implementing more restrictive vaccine eligibility requirements. METHODS: A Susceptible-Exposed-Infected-Recovered (SEIR) model was used to predict COVID-19 cases and hospitalisations in the UK. A COVID-19 vaccination and infection consequences decision tree was used to predict health outcomes, costs and quality-adjusted life-year (QALY) losses associated with symptomatic SARS-CoV-2 infections as well as costs and QALY losses associated with COVID-19 vaccination and adverse events over a 1-year time horizon. RESULTS: Compared to no vaccination, an Autumn mRNA-1273 vaccination campaign is predicted to decrease the number of symptomatic infections from 21.9 million to 20.0 million, and the number of hospitalisations from 150,000 to 116,000. COVID-related deaths and long COVID cases are decreased by 7200 and 18,000, respectively. Costs saved are £467.7 million with 52,000 QALYs gained, resulting in an incremental cost-effectiveness ratio (ICER) of £8963/QALY gained. The ICER was most sensitive to infection incidence, population immunity before the vaccination campaign, vaccine effectiveness against hospitalisation, and hospitalisation probabilities. Narrowing the vaccination eligibility criteria to those aged ≥75 years and those aged 6 months-74 years at high risk of severe outcomes results in fewer outcomes prevented, with 525,300 more symptomatic infections, 6000 more hospitalisations, 1100 additional deaths, and 5200 additional cases of long COVID, compared to the base case. Vaccination of the broader population compared to the narrower population is associated with an ICER of £11,753/QALY gained. CONCLUSIONS: Vaccinating adults aged ≥65 years and high-risk individuals 6 months-64 years remains cost-effective compared both to no vaccination and vaccination of the narrower population.
Factors associated with intention to obtain HPV vaccination at ages 9-10 among parents with varied prior vaccine decision making experiences and choices.
Fontenot HB, Liebermann EJ, Thompson EL … +5 more , Coad S, Kornides M, Matsunaga M, Lim E, Zimet G
Vaccine · 2026 Jul · PMID 42134134 · Publisher ↗
BACKGROUND AND OBJECTIVES: This study aimed to understand how a routine HPV vaccine recommendation at age 9-10 rather than 11-12 may influence parents' vaccine intentions, including parents with varied experience/prior c...
BACKGROUND AND OBJECTIVES: This study aimed to understand how a routine HPV vaccine recommendation at age 9-10 rather than 11-12 may influence parents' vaccine intentions, including parents with varied experience/prior choices related to HPV vaccine decision-making. Additionally, we sought to identify factors (older child vaccination status, items informed by the Theory of Planned Behavior, and socio-demographic/health characteristics) associated with vaccine intention for ages 9-10. METHODS: A national online survey of parents of children ages 9-10 who had not yet received the HPV vaccine was conducted in October 2024. Participants were recruited though a US research panel and assigned to one of three groups: (Group 1) parents without an older child; (Group 2) parents with an HPV-vaccinated older child; or (Group 3) parents with a non-HPV-vaccinated older child. Multivariable linear regression models identified factors associated with HPV vaccine intention at ages 9-10 for each group. RESULTS: The final sample included 2272 parents (Group 1: 41%, Group 2: 35%, Group 3: 24%). Overall mean score for intention to vaccinate at ages 9-10 was 3.21. Group 2 parents reported the highest perceived benefits and lowest perceived barriers for vaccinating at ages 9-10. Across all groups, those who indicated they follow health care provider recommendations for age of vaccination and those who perceive a benefit to vaccinating as early as possible had greater intentions to vaccinate at ages 9-10. CONCLUSION: These findings may help to inform health policy related to HPV vaccination and provider communication strategies. Moving the age of routine vaccination to ages 9-10 may not increase overall vaccination rates, but expansion of the age range (9-12) may create opportunities for repetitive provider recommendation and communication strategies that are personalized based on the parents' prior vaccine decision making.
Mobile health strategies to improve HPV vaccination uptake among parents of adolescent girls: a scoping review.
Opaleye OO, Esan DT
Vaccine · 2026 Jul · PMID 42134133 · Publisher ↗
BACKGROUND: Human papillomavirus (HPV) vaccination is a highly effective primary prevention strategy against cervical cancer. However, despite strong evidence of vaccine efficacy and safety, uptake among adolescent girls...
BACKGROUND: Human papillomavirus (HPV) vaccination is a highly effective primary prevention strategy against cervical cancer. However, despite strong evidence of vaccine efficacy and safety, uptake among adolescent girls remains suboptimal globally, particularly in low- and middle-income countries. Mobile health (mHealth) technologies have emerged as promising tools to address parental concerns, reduce vaccine hesitancy, and strengthen parental engagement in vaccination decision-making. OBJECTIVE: This scoping review aimed to synthesize evidence on the types of mHealth strategies implemented to improve HPV vaccine uptake among parents of adolescent girls and to examine the outcomes of these interventions. METHODS: A systematic search of major databases identified studies evaluating mHealth interventions targeting parental decision-making regarding HPV vaccination. Eligible interventions included text messaging, mobile applications, chatbots, web-based educational platforms, and other digital health tools. Data were charted and synthesized narratively. KEY FINDINGS: mHealth interventions were associated with significant improvements in HPV vaccine uptake across multiple settings. SMS-based interventions consistently increased vaccination rates, while chatbot, web-based, and mobile app interventions improved parental knowledge, vaccine literacy, intention to vaccinate, and, in several studies, actual vaccine uptake. However, intervention effectiveness varied by socioeconomic context, digital access, and cultural factors. CONCLUSION: mHealth technologies represent cost-effective and scalable strategies to improve HPV vaccine uptake by enhancing parental knowledge, reducing hesitancy, and supporting informed decision-making. Future implementation should prioritize culturally tailored, equity-focused approaches and integrate digital interventions with community-based engagement to maximize impact.
Maternal preferences for infant respiratory syncytial virus (RSV) preventives: an Australian discrete choice experiment.
Danchin M, Rak A, Vasiliadis S … +5 more , Wang B, Buttery J, Kaufman J, Marshall H, Chen G
Vaccine · 2026 Jul · PMID 42134132 · Publisher ↗
OBJECTIVES: Two RSV preventatives, a maternal RSV vaccine and a long-acting monoclonal antibody, were introduced in Australia in 2025. In the year prior to program introduction, we explored maternal acceptability, prefer...
OBJECTIVES: Two RSV preventatives, a maternal RSV vaccine and a long-acting monoclonal antibody, were introduced in Australia in 2025. In the year prior to program introduction, we explored maternal acceptability, preferences, awareness and knowledge of disease and provider delivery preferences. DESIGN: Discrete Choice Experiment (DCE). SETTING: Qualitative data from online focus groups informed a national DCE survey. PARTICIPANTS: Qualitative data from Australian mothers with a child <2 years was collected through focus groups, identifying key themes for decision-making. The final attributes for the DCE survey included effectiveness, cost, safety, timing, and risk perception of the disease and was administered to 1500 pregnant people and mothers with a child <2 years. MAIN OUTCOME MEASURES: The primary outcomes were acceptability and maternal preferences for RSV preventatives and secondary outcomes were maternal awareness/knowledge of RSV and provider delivery preference. RESULTS: We found knowledge of the monoclonal antibody and perception of disease severity were low and maternal vaccine decision-making and acceptability of preventatives is strongly influenced by cost, effectiveness and safety. Overall, 51.4% of mothers preferred the maternal vaccine and 24.3% preferred the monoclonal antibody or were 'not sure' and general practitioners (GPs) were the preferred provider for delivery. CONCLUSION: Prior to the introduction of the hybrid RSV prevention program for infants in Australia in February 2025, we found that awareness of disease and RSV preventatives was low and that decision-making was influenced by cost, effectiveness and safety concerns. This study highlights the need for a national RSV implementation strategy and harmonised, Commonwealth-funded RSV program to optimise equitable uptake.
Association of HLA class II haplotypes with antibody concentrations after diphtheria-tetanus acellular pertussis booster vaccination in four age groups of Finnish participants.
Anabe D, Ilonen J, Barkoff AM … +7 more , Teräsjärvi JT, Mertsola J, van Gageldonk P, Buisman A, Kiviniemi M, Lempainen J, He Q
Vaccine · 2026 Jul · PMID 42134131 · Publisher ↗
BACKGROUND: Despite widespread use of whole-cell (wP) and acellular (aP) pertussis vaccines, outbreaks persist in many countries. Polymorphisms in HLA class II molecules, which present antigens to CD4 T cells, may play a...
BACKGROUND: Despite widespread use of whole-cell (wP) and acellular (aP) pertussis vaccines, outbreaks persist in many countries. Polymorphisms in HLA class II molecules, which present antigens to CD4 T cells, may play a vital role in vaccine responses. Emerging evidence suggests that HLA-DR/DQ variants can significantly influence wP vaccine responses. This study investigated the possible association of HLA class II haplotypes with antibody concentrations after aP booster vaccination. MATERIALS AND METHODS: Healthy Finnish children (7-10y, n = 37), adolescents (11-15y, n = 37), young adults (20-34y, n = 25), and older adults (60-70y, n = 25) received a Tdap3-IPV booster. Serum antibodies against pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), diphtheria toxoid (DT), and tetanus toxoid (TT), as well as PT-neutralizing antibodies (PTNA), were measured before, one month, and one year after the booster. Participants were HLA-typed with a stepwise HLA-DR/DQ screening system using PCR followed by allele-specific probe hybridization. The frequency of HLA haplotypes was compared to the control cohort from the Finnish Pediatric Diabetes Register, which was constructed from parental haplotypes not passed down to diabetic children. RESULTS: The HLA DR-DQ haplotype frequencies in our cohort did not differ from the control group. Two associations survived FDR correction: (DR7)-DQA1*02:01-DQB1*02 with lower anti-PT IgG and (DR15)-DQB1*06:02 with a time-dependent anti-FHA IgG response with higher pre-booster concentrations. Nominally, (DR8)-DQB1*04 and (DR7)-DQA1*02:01-DQB1*02 carriers had lower PTNA; (DR9)-DQA1*03-DQB1*03:03, (DR15)-DQB1*06:02, and DRB1*04:01-DQA1*03-DQB1*03:02 carriers had higher anti-PT and anti-Prn concentrations; and (DR13)-DQB1*06:03 carriers had consistently lower anti-DT across all timepoints. CONCLUSIONS: The present study highlights a potential role of certain HLA haplotypes in modulating immune responses to aP vaccination. These findings emphasize the importance of further research to clarify how HLA class II haplotypes influence aP vaccine responses in various populations.
Seroprevalence and predictors of measles antibody positivity among children aged 18-24 months in Pakistan: a national survey.
Javed N, Sabir M, Saqib MAN … +1 more , Abbas S
Vaccine · 2026 Jul · PMID 42127548 · Publisher ↗
BACKGROUND: Measles remain a leading cause of childhood morbidity and mortality. Despite improved vaccine coverage, the number of laboratory-confirmed measles cases in Pakistan doubled between 2019 and 2020. Although an...
BACKGROUND: Measles remain a leading cause of childhood morbidity and mortality. Despite improved vaccine coverage, the number of laboratory-confirmed measles cases in Pakistan doubled between 2019 and 2020. Although an effective vaccine has been available for decades, sporadic outbreaks continue to occur. This study aimed to determine the seroprevalence of measles IgG antibodies among vaccinated children in Pakistan. METHODS: A cross-sectional survey was conducted between April 2019 and October 2020 in seven districts across Pakistan. Using a multistage sampling technique, healthy children aged 18-24 months with a history of measles vaccination were randomly enrolled after obtaining informed written consent. Venous blood samples (3 cc) were collected and tested for measles IgG antibodies using ELISA. RESULTS: Among 3596 vaccinated children, 65% were seropositive for measles IgG antibodies. Vaccine coverage was high, with 90% receiving the first measles dose (MCV1) administered at 9 months of age and 78% the second dose (MCV2) administered at 15 months. Seropositivity was significantly associated with vaccination source, documentation status, rural residence, place of delivery, and history of prior measles infection. Higher seroprevalence was observed among children vaccinated by mobile vaccinators compared to other vaccination settings. CONCLUSION: Seroconversion among vaccinated children was suboptimal, with only 65% achieving protective antibody levels. The first dose of measles vaccine appeared particularly important for antibody development. Strengthening vaccination services, ensuring delivery through trained vaccinators, and conducting regular seroprevalence surveys are essential for evidence-based policies to achieve measles elimination in Pakistan.
Pregnant women's knowledge, perceptions, and intention to receive a future group B Streptococcus (GBS) vaccine: a cross-sectional study.
Ladomenou F, Gkorla E, Matalliotakis M … +2 more , Moulias E, Skentou C
Vaccine · 2026 Jul · PMID 42127547 · Publisher ↗
BACKGROUND: Group B Streptococcus (GBS) is a major cause of neonatal morbidity and mortality. As maternal GBS vaccines progress toward licensure, understanding the determinants of acceptance is essential. This study asse...
BACKGROUND: Group B Streptococcus (GBS) is a major cause of neonatal morbidity and mortality. As maternal GBS vaccines progress toward licensure, understanding the determinants of acceptance is essential. This study assessed pregnant women's knowledge of GBS, perceptions of vaccine safety and effectiveness, and intention to receive a future maternal GBS vaccine in Greece. METHODS: A cross-sectional survey was conducted among pregnant women attending routine antenatal care at a tertiary hospital in Northwest Greece (July-November 2025). A structured, self-administered questionnaire assessed GBS knowledge, awareness of preventive measures, beliefs regarding vaccine safety and breastfeeding, prior maternal vaccination, and intention to receive a future GBS vaccine. Descriptive statistics, chi-square tests, and binary logistic regression were used to identify predictors of vaccine acceptance. RESULTS: A total of 421 women participated. General awareness of GBS was moderate (68.9%), while awareness of preventive measures, neonatal consequences, and prenatal testing was lower. Intention to accept a future GBS vaccine was evenly divided (49.9%). In multivariable analysis, higher educational level, awareness of preventive measures, pregnancy complications, and prior Tdap vaccination were associated with increased acceptance. Concerns about long-term adverse effects, perceived impact on breastfeeding, and conception via IVF were associated with reduced acceptance. CONCLUSIONS: Despite limited GBS awareness, nearly half of pregnant women expressed willingness to receive a future GBS vaccine. Acceptance was shaped by safety perceptions, breastfeeding concerns, and prior maternal vaccination. Strengthening communication, consistent provider messaging, and targeted support for specific subgroups may be important for the successful implementation of maternal GBS vaccination in Greece.
A recombinant goat pox virus expressing the Brucella OMP25 antigen conferring moderate protection against B. abortus in mice.
Wang S, Li Z, Zhang H … +3 more , Sun Z, Wei F, Li Q
Vaccine · 2026 Jul · PMID 42119393 · Publisher ↗
Brucellosis, a widespread zoonosis that currently lacks safe and efficient vaccines, presenting a serious threat to both public and animal health. Capripoxviruses (CaPV) have emerged as promising vaccine vectors capable...
Brucellosis, a widespread zoonosis that currently lacks safe and efficient vaccines, presenting a serious threat to both public and animal health. Capripoxviruses (CaPV) have emerged as promising vaccine vectors capable of delivering foreign antigens. In this study, we assessed the immunogenicity and protective efficacy of a recombinant goatpox virus (rGTPV) expressing Brucella outer membrane protein 25 (rGTPV-OMP25) in a mouse model. Immunization with rGTPV-OMP25 elicited a robust Brucella-specific IgG response and stimulated a balanced Th1 (IFN-γ, IL-2) and Th2 (IL-4, IL-5) cytokine profile. Following challenge with Brucella abortus S19, vaccinated mice showed a significant reduction in bacterial load in the spleen, indicating partial protection. Although the mouse model (BALB/c) does not fully replicate natural host conditions, it was employed here for preliminary evaluation. Together, these results demonstrate that rGTPV-OMP25 induces both humoral and cellular immune responses and confers measurable protection against B. abortus infection, supporting its potential as a promising vaccine candidate for further development.
Design and feasibility considerations for a phase 3 efficacy trial of the M72/AS01 tuberculosis vaccine.
Dagnew AF, Noble R, Cinar A … +9 more , Burhan E, Churchyard G, Fairlie L, Hanekom WA, Muyoyeta M, Mwandumba HC, Nduba V, Curran M, Schmidt AC
Vaccine · 2026 Jul · PMID 42119392 · Publisher ↗
BACKGROUND: M72/AS01 demonstrated 50% vaccine efficacy against laboratory-confirmed pulmonary tuberculosis (TB) disease (VE[D]) among interferon-gamma release assay (IGRA)-positive, HIV-negative adults in a phase 2b tria...
BACKGROUND: M72/AS01 demonstrated 50% vaccine efficacy against laboratory-confirmed pulmonary tuberculosis (TB) disease (VE[D]) among interferon-gamma release assay (IGRA)-positive, HIV-negative adults in a phase 2b trial. Simulations were used to inform the phase 3 design. METHODS: We conducted event-driven simulations using lower bound (LB) of the two-sided 95% confidence interval (CI) for VE(D). For IGRA-positive participants, assumptions included 1:1 randomization, 9000 participants/arm, 0.4% TB incidence/year, 55% true VE(D), 5% dropout/year, and two-year enrollment. Enrollment irrespective of baseline IGRA status (mixed IGRA-status population) and IGRA-negative-only scenarios were explored to estimate sample sizes and trial duration. RESULTS: Simulations demonstrated that 110 events rule out a VE(D) 95% CI LB ≤10%, and 185 events rule out ≤25%, assuming ≥90% power and a true VE(D) of 55%. With 18,000 IGRA-positive participants, simulations projected a 90% probability of accruing 110 events within 3.5 to 4 years and 185 within 5.5 to 6 years. In the mixed IGRA-status population, few endpoints occurred among IGRA-negative participants, yielding insufficient power. Standalone VE(D) evaluation in IGRA-negative participants required large sample sizes (approximately 134,800) and prolonged timelines, indicating infeasibility. Accordingly, the selected primary objective of the phase 3 trial was to confirm VE(D) in IGRA-positive HIV-negative participants using LB of 95% CI for VE(D) > 10% after 110 events; secondary objectives include safety and immunogenicity in HIV-negative IGRA-positive; HIV-negative IGRA-negative; and HIV-positive individuals irrespective of IGRA status. CONCLUSIONS: An IGRA-positive-enriched, event-driven phase 3 trial is feasible to confirm VE(D) of M72/AS01 while evaluating safety and immunogenicity across IGRA and HIV groups.
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