Pub Date : 2026-03-19Epub Date: 2026-02-11DOI: 10.1016/j.vaccine.2026.128336
Matthew R. Boyce , Tara Kirk Sell
This study reports on an online survey characterizing support for policies requiring longitudinal and targeted safety testing for new and existing childhood vaccines, as well as the impact of these policies on trust in vaccine safety. 1042 participants were included in the data analysis. For new vaccines, 66.8% of participants indicated support for longitudinal testing, and 63.0% supported targeted testing. For existing vaccines, 67.6% of participants indicated support for longitudinal testing, and 61.0% supported targeted testing. 57.0% of participants reported that their trust in vaccine safety would increase if existing vaccines underwent additional longitudinal testing, 55.6% reported that it would increase if they underwent additional targeted testing; 42.4% reported that their trust increased as a result of the recent dismissal of the CDC's Advisory Committee on Immunization Practices. Policy support and trust impacts varied significantly according to participant gender, support for the Make America Healthy Again agenda, and vaccine hesitancy.
{"title":"Support for vaccine-related priorities included in the Make Our Children Healthy Again Assessment and impacts on trust in vaccine safety: a national survey of parents in the United States","authors":"Matthew R. Boyce , Tara Kirk Sell","doi":"10.1016/j.vaccine.2026.128336","DOIUrl":"10.1016/j.vaccine.2026.128336","url":null,"abstract":"<div><div>This study reports on an online survey characterizing support for policies requiring longitudinal and targeted safety testing for new and existing childhood vaccines, as well as the impact of these policies on trust in vaccine safety. 1042 participants were included in the data analysis. For new vaccines, 66.8% of participants indicated support for longitudinal testing, and 63.0% supported targeted testing. For existing vaccines, 67.6% of participants indicated support for longitudinal testing, and 61.0% supported targeted testing. 57.0% of participants reported that their trust in vaccine safety would increase if existing vaccines underwent additional longitudinal testing, 55.6% reported that it would increase if they underwent additional targeted testing; 42.4% reported that their trust increased as a result of the recent dismissal of the CDC's Advisory Committee on Immunization Practices. Policy support and trust impacts varied significantly according to participant gender, support for the Make America Healthy Again agenda, and vaccine hesitancy.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"76 ","pages":"Article 128336"},"PeriodicalIF":4.5,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174750","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}
Pub Date : 2026-03-19Epub Date: 2026-02-10DOI: 10.1016/j.vaccine.2026.128314
Emma Sidebotham , Deborah M. Caldwell , Sarah R. Davies , Zak A. Thornton , Elisabeth Aiton , Elizabeth Emsley , Elizabeth Rose-Innes , Sarah Dawson , Julie Yates , Louise Letley , Clare E. French
Background
There are known inequalities in vaccine uptake and the distribution of vaccine-preventable diseases. Understanding the best ways to increase vaccine uptake among socially excluded groups is vital to reduce these inequalities.
Aim
To assess the effectiveness of interventions to increase vaccine uptake among socially excluded groups.
Methods
Systematic review of randomised controlled trials (RCTs) and non-randomised studies of interventions. Studies were eligible if they evaluated an intervention to increase uptake of any vaccination on the World Health Organization immunisation schedule and focused on socially excluded populations (e.g. people experiencing homelessness, people who use drugs). MEDLINE, Embase and PsycINFO were searched to January 2025. Risk of bias was assessed using Cochrane risk of bias tools. Data were analysed using random-effects meta-analyses and effect direction plots.
Results
Of 2673 records, 20 studies were eligible (18 RCTs and two non-randomised studies). Most (13 studies) were conducted among people who use drugs and investigated hepatitis B (HBV) vaccination uptake (16 studies). Various interventions were identified: accelerated HBV vaccination schedules (six studies); financial incentives (four); educational initiatives (two); motivational interviewing (two); post-natal home visits (one); enhanced outreach and on-the-spot vaccination (one), and four varying interventions delivered as part of care co-ordination or nurse-guided case management models. Nine studies were at high risk of bias, six had some concerns and five were at low risk.
Meta-analyses indicated a potential beneficial effect of accelerated schedules (odds ratio (OR):1.45, 95%CI:1.10–1.91) and financial incentives (OR:5.36, 95%CI:2.61–11.01). Confidence in the evidence was judged to be ‘moderate’ for both these interventions. Evidence for the effectiveness of other types of interventions was inconclusive.
Conclusion
We identify some promising strategies for improving uptake of vaccinations among some socially excluded groups. The conclusions that can be drawn are, however, limited by the lack of high-quality studies on the topic.
{"title":"Interventions to increase vaccine uptake among socially excluded groups: A systematic review","authors":"Emma Sidebotham , Deborah M. Caldwell , Sarah R. Davies , Zak A. Thornton , Elisabeth Aiton , Elizabeth Emsley , Elizabeth Rose-Innes , Sarah Dawson , Julie Yates , Louise Letley , Clare E. French","doi":"10.1016/j.vaccine.2026.128314","DOIUrl":"10.1016/j.vaccine.2026.128314","url":null,"abstract":"<div><h3>Background</h3><div>There are known inequalities in vaccine uptake and the distribution of vaccine-preventable diseases. Understanding the best ways to increase vaccine uptake among socially excluded groups is vital to reduce these inequalities.</div></div><div><h3>Aim</h3><div>To assess the effectiveness of interventions to increase vaccine uptake among socially excluded groups.</div></div><div><h3>Methods</h3><div>Systematic review of randomised controlled trials (RCTs) and non-randomised studies of interventions. Studies were eligible if they evaluated an intervention to increase uptake of any vaccination on the World Health Organization immunisation schedule and focused on socially excluded populations (e.g. people experiencing homelessness, people who use drugs). MEDLINE, Embase and PsycINFO were searched to January 2025. Risk of bias was assessed using Cochrane risk of bias tools. Data were analysed using random-effects meta-analyses and effect direction plots.</div></div><div><h3>Results</h3><div>Of 2673 records, 20 studies were eligible (18 RCTs and two non-randomised studies). Most (13 studies) were conducted among people who use drugs and investigated hepatitis B (HBV) vaccination uptake (16 studies). Various interventions were identified: accelerated HBV vaccination schedules (six studies); financial incentives (four); educational initiatives (two); motivational interviewing (two); post-natal home visits (one); enhanced outreach and on-the-spot vaccination (one), and four varying interventions delivered as part of care co-ordination or nurse-guided case management models. Nine studies were at high risk of bias, six had some concerns and five were at low risk.</div><div>Meta-analyses indicated a potential beneficial effect of accelerated schedules (odds ratio (OR):1.45, 95%CI:1.10–1.91) and financial incentives (OR:5.36, 95%CI:2.61–11.01). Confidence in the evidence was judged to be ‘moderate’ for both these interventions. Evidence for the effectiveness of other types of interventions was inconclusive.</div></div><div><h3>Conclusion</h3><div>We identify some promising strategies for improving uptake of vaccinations among some socially excluded groups. The conclusions that can be drawn are, however, limited by the lack of high-quality studies on the topic.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"76 ","pages":"Article 128314"},"PeriodicalIF":4.5,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146159862","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}
Pub Date : 2026-03-19Epub Date: 2026-02-10DOI: 10.1016/j.vaccine.2026.128325
Zhiqiang Li , Shuli Wang , Huijun Zhang , Ruirui Li , Yanyan Cui , Jinliang Zhang , Junfang Hao , Qifeng Li
Brucellosis is a globally significant zoonotic disease that affects both animals and humans. Current vaccines against Brucella abortus (B. abortus), such as A19, suffer from several limitations, including residual virulence in animals and humans and the inability to serologically differentiate infected from vaccinated animals. Here, we describe attenuated strains that match the protective efficacy of the current vaccine but offer a substantially improved safety profile and enable differentiation from infection, addressing key limitations that have hampered current control tools. We constructed a double-gene deletion mutant (A19ΔfeuPΔfeuQ) from A19 by removing genes encoding a two-component regulatory system (TCS) located on chromosome II. The A19ΔfeuPΔfeuQ mutant exhibited a >1.5-log reduction in intracellular survival and BALB/c mice, indicating marked attenuation. Vaccination with this mutant induced significantly higher titers of IgG, and provided a 2.34-log greater reduction in bacterial burden at 4 weeks post-challenge. Additionally, the FEUP and FEUQ proteins served as specific antigens enabling serological differentiation between infected and vaccinated animals. These findings demonstrate that the highly attenuated A19ΔfeuPΔfeuQ mutant is a promising live vaccine candidate against bovine brucellosis, combining efficacy, improved safety, and diagnostic compatibility.
{"title":"The Brucella abortus A19ΔfeuPΔfeuQ double-mutant is highly attenuated and confers protection in BALB/c mice","authors":"Zhiqiang Li , Shuli Wang , Huijun Zhang , Ruirui Li , Yanyan Cui , Jinliang Zhang , Junfang Hao , Qifeng Li","doi":"10.1016/j.vaccine.2026.128325","DOIUrl":"10.1016/j.vaccine.2026.128325","url":null,"abstract":"<div><div>Brucellosis is a globally significant zoonotic disease that affects both animals and humans. Current vaccines against <em>Brucella abortus</em> (<em>B. abortus</em>), such as A19, suffer from several limitations, including residual virulence in animals and humans and the inability to serologically differentiate infected from vaccinated animals. Here, we describe attenuated strains that match the protective efficacy of the current vaccine but offer a substantially improved safety profile and enable differentiation from infection, addressing key limitations that have hampered current control tools. We constructed a double-gene deletion mutant (A19Δ<em>feuP</em>Δ<em>feuQ</em>) from A19 by removing genes encoding a two-component regulatory system (TCS) located on chromosome II. The A19Δ<em>feuP</em>Δ<em>feuQ</em> mutant exhibited a >1.5-log reduction in intracellular survival and BALB/c mice, indicating marked attenuation. Vaccination with this mutant induced significantly higher titers of IgG, and provided a 2.34-log greater reduction in bacterial burden at 4 weeks post-challenge. Additionally, the FEUP and FEUQ proteins served as specific antigens enabling serological differentiation between infected and vaccinated animals. These findings demonstrate that the highly attenuated A19Δ<em>feuP</em>Δ<em>feuQ</em> mutant is a promising live vaccine candidate against bovine brucellosis, combining efficacy, improved safety, and diagnostic compatibility.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"76 ","pages":"Article 128325"},"PeriodicalIF":4.5,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138227","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}
Pub Date : 2026-03-19Epub Date: 2026-02-10DOI: 10.1016/j.vaccine.2026.128293
Qi Cao , Siyu Du , Keyi Yang , Mei Liu , Li Xiao , Qiuyi Wang , Jing Fu , Huili Zhu
Objective
To assess the impact of SARS-CoV-2 infection and vaccination on fertility and assisted reproductive technology (ART) outcomes.
Study design
This is an Umbrella Review of Meta-analyses. We searched major databases until December 30, 2023. The quality of evidence was assessed by a Measurement Tool to Assess Systematic Reviews and the Grading of Recommendations, Assessment, Development and Evaluation.
Results
Of 647 studies identified, 14 studies with 40 outcomes were included. COVID-19 infection may decrease semen quality in men, including semen volume (WMD, −0.48 ml; 95% CI, −0.59 to −0.36 ml), total sperm count (WMD, −34.84 × 10^6; 95% CI, −43.51 to −26.17 × 10^6), sperm concentration (WMD, −16.23 × 10^6/ml; 95% CI, −25.56 × 10^6 to −6.89 × 10^6), viability (SMD, −0.66; 95% CI, −1.27 to −0.06), and total sperm motility (SMD, −0.61; 95% CI, −0.96 to −0.25), and elevated levels of estradiol (SMD 0.652; 95% CI, 0.254 to 1.049; p = 0.001) and prolactin (SMD 0.305; 95% CI, 0.045 to 0.566; p = 0.022). However, it did not significantly affect testosterone levels. Notably, even after recovery (over 90 days), sperm concentration and motility remained lower compared to uninfected individuals. Conversely, COVID-19 showed minimal impact on female ovarian reserve (including antral follicle count, AMH) or ART outcomes (including oocyte number and quality, embryo quality, implantation rates, clinical pregnancy rates and miscarriage rates). Vaccination also had minimal effects on both sexes. Evidence quality was generally very low, highlighting the need for high-quality, long-term studies.
Conclusion
SARS-CoV-2 infection primarily affects male fertility, leading to reductions in sperm quality, count, and motility. However, female fertility and ART outcomes show little to no impact. COVID-19 vaccination shows minimal impact on fertility and ART outcomes. The quality of evidence is rated as very low to low. High-quality prospective studies with longer follow-up periods are needed.
{"title":"Assessing the impact of SARS-CoV-2 infection and vaccination on fertility and assisted reproductive techniques outcomes: an umbrella review","authors":"Qi Cao , Siyu Du , Keyi Yang , Mei Liu , Li Xiao , Qiuyi Wang , Jing Fu , Huili Zhu","doi":"10.1016/j.vaccine.2026.128293","DOIUrl":"10.1016/j.vaccine.2026.128293","url":null,"abstract":"<div><h3>Objective</h3><div>To assess the impact of SARS-CoV-2 infection and vaccination on fertility and assisted reproductive technology (ART) outcomes.</div></div><div><h3>Study design</h3><div>This is an Umbrella Review of Meta-analyses. We searched major databases until December 30, 2023. The quality of evidence was assessed by a Measurement Tool to Assess Systematic Reviews and the Grading of Recommendations, Assessment, Development and Evaluation.</div></div><div><h3>Results</h3><div>Of 647 studies identified, 14 studies with 40 outcomes were included. COVID-19 infection may decrease semen quality in men, including semen volume (WMD, −0.48 ml; 95% CI, −0.59 to −0.36 ml), total sperm count (WMD, −34.84 × 10^6; 95% CI, −43.51 to −26.17 × 10^6), sperm concentration (WMD, −16.23 × 10^6/ml; 95% CI, −25.56 × 10^6 to −6.89 × 10^6), viability (SMD, −0.66; 95% CI, −1.27 to −0.06), and total sperm motility (SMD, −0.61; 95% CI, −0.96 to −0.25), and elevated levels of estradiol (SMD 0.652; 95% CI, 0.254 to 1.049; <em>p</em> = 0.001) and prolactin (SMD 0.305; 95% CI, 0.045 to 0.566; <em>p</em> = 0.022). However, it did not significantly affect testosterone levels. Notably, even after recovery (over 90 days), sperm concentration and motility remained lower compared to uninfected individuals. Conversely, COVID-19 showed minimal impact on female ovarian reserve (including antral follicle count, AMH) or ART outcomes (including oocyte number and quality, embryo quality, implantation rates, clinical pregnancy rates and miscarriage rates). Vaccination also had minimal effects on both sexes. Evidence quality was generally very low, highlighting the need for high-quality, long-term studies.</div></div><div><h3>Conclusion</h3><div>SARS-CoV-2 infection primarily affects male fertility, leading to reductions in sperm quality, count, and motility. However, female fertility and ART outcomes show little to no impact. COVID-19 vaccination shows minimal impact on fertility and ART outcomes. The quality of evidence is rated as very low to low. High-quality prospective studies with longer follow-up periods are needed.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"76 ","pages":"Article 128293"},"PeriodicalIF":4.5,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146159829","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}
Pub Date : 2026-03-07Epub Date: 2026-01-22DOI: 10.1016/j.vaccine.2026.128265
Florence Anne Barbey , Maria Otth , Sabine Kroiss , Daniel Drozdov , Christoph Berger
Background
Childhood cancer diagnosis and treatment cause significant immunosuppression, increasing vulnerability to vaccine-preventable diseases and disrupting routine vaccination schedules. In Switzerland, vaccination guidelines to support physicians caring for these patients were published in 2022. Adherence to these recommendations among pediatric cancer patients remains unknown.
Methods
We conducted a retrospective chart review of pediatric cancer patients (0–16 years at diagnosis) treated at two Swiss tertiary care centers between June 2022 and November 2024. Vaccine uptake was assessed at diagnosis, during, and after treatment using descriptive analyses. Exploratory analyses evaluated risk factors for under-vaccination, and occurrence of vaccine-preventable diseases was documented.
Results
Among 105 participants (median age at diagnosis 7.6 years [IQR 2.7–12.9]), uptake of vaccines recommended during treatment was low (pneumococcal conjugate vaccine 5%, influenza vaccine 10%, COVID-19 vaccine 19%). Post-treatment vaccine uptake was delayed and insufficient, ranging from 0 to 41% within 0–3 months following recommendation date and from 15 to 76% thereafter, depending on the vaccine. Younger age at diagnosis was associated with complete post-treatment vaccine uptake (p = 0.03). Vaccine-preventable diseases, including COVID-19, influenza, varicella, herpes zoster, and pertussis, occurred in 30/105 participants (29%). Most vaccines during (82%), and all vaccines after treatment (100%), were administered in primary care.
Conclusion
In a setting where post-treatment vaccination relies exclusively on primary care and no structured in-hospital measures are set in place, vaccine uptake among pediatric cancer patients remained insufficient. Targeted strategies are needed to improve guidelines adherence and reduce the burden of vaccine-preventable diseases, particularly among older children.
{"title":"Adherence to national vaccination guidelines among pediatric cancer patients: a retrospective study from two tertiary care centers in Switzerland","authors":"Florence Anne Barbey , Maria Otth , Sabine Kroiss , Daniel Drozdov , Christoph Berger","doi":"10.1016/j.vaccine.2026.128265","DOIUrl":"10.1016/j.vaccine.2026.128265","url":null,"abstract":"<div><h3>Background</h3><div>Childhood cancer diagnosis and treatment cause significant immunosuppression, increasing vulnerability to vaccine-preventable diseases and disrupting routine vaccination schedules. In Switzerland, vaccination guidelines to support physicians caring for these patients were published in 2022. Adherence to these recommendations among pediatric cancer patients remains unknown.</div></div><div><h3>Methods</h3><div>We conducted a retrospective chart review of pediatric cancer patients (0–16 years at diagnosis) treated at two Swiss tertiary care centers between June 2022 and November 2024. Vaccine uptake was assessed at diagnosis, during, and after treatment using descriptive analyses. Exploratory analyses evaluated risk factors for under-vaccination, and occurrence of vaccine-preventable diseases was documented.</div></div><div><h3>Results</h3><div>Among 105 participants (median age at diagnosis 7.6 years [IQR 2.7–12.9]), uptake of vaccines recommended during treatment was low (pneumococcal conjugate vaccine 5%, influenza vaccine 10%, COVID-19 vaccine 19%). Post-treatment vaccine uptake was delayed and insufficient, ranging from 0 to 41% within 0–3 months following recommendation date and from 15 to 76% thereafter, depending on the vaccine. Younger age at diagnosis was associated with complete post-treatment vaccine uptake (<em>p</em> = 0.03). Vaccine-preventable diseases, including COVID-19, influenza, varicella, herpes zoster, and pertussis, occurred in 30/105 participants (29%). Most vaccines during (82%), and all vaccines after treatment (100%), were administered in primary care.</div></div><div><h3>Conclusion</h3><div>In a setting where post-treatment vaccination relies exclusively on primary care and no structured in-hospital measures are set in place, vaccine uptake among pediatric cancer patients remained insufficient. Targeted strategies are needed to improve guidelines adherence and reduce the burden of vaccine-preventable diseases, particularly among older children.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128265"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032253","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}
Pub Date : 2026-03-07Epub Date: 2026-01-20DOI: 10.1016/j.vaccine.2026.128251
Kerstin Kling , Annika Falman , Lisa Branke , Michael Ramharter , Camilla Rothe , Christian Schönfeld , Thomas Grünewald
Background
Infections with the chikungunya virus are increasingly reported due to many reasons including climate change. Two vaccines against chikungunya have recently been approved in Europe, the live-attenuated vaccine (LAV) Ixchiq and the virus like particle (VLP) vaccine Vimkunya. However, no systematic review of phase 3 clinical trial data has been published that summarizes the currently available evidence on the immunogenicity, tolerability, and safety of these vaccines. Therefore, these data were systematically analyzed by a working group of the German Standing Committee on Vaccination (STIKO) and the German Society for Tropical Medicine, Travel Medicine and Global Health (DTG).
Methods
We conducted a systematic review of the immunogenicity, tolerability and safety of Ixchiq and Vimkunya using Embase and PubMed (OVID) according to predefined PICO criteria, including placebo-controlled randomized control trials, cohort, and case-control studies. Risk of bias (RoB) was assessed with the RoB 2-tool. Additionally, post-marketing safety data were studied.
Results
Clinical efficacy data were not available. Instead, seropositivity rates above a predefined threshold served as a surrogate of protection. Both vaccines demonstrated strong immunogenicity with seroprotection rates for Ixchiq of >98% after 4 weeks, and for Vimkunya after 3 weeks of >97% in 12–59-year-olds and > 87% in ≥65-year-olds. In the pivotal studies, both vaccines showed also an acceptable safety profile. Post-marketing safety data showed a higher risk for serious adverse events in elderly patients for Ixchiq.
Conclusion
In addition to mosquito protection and vector control, two vaccines with a good efficacy profile based on the surrogate marker of seroprotection are now available to prevent chikungunya. While both vaccines showed acceptable tolerability, the safety of vaccines must be continuously assessed based on further data from post-marketing surveillance of the respective populations.
{"title":"Vaccination against chikungunya - a systematic review on the immunogenicity, tolerability, and safety of the live-attenuated vaccine (LAV) Ixchiq and the virus like particle (VLP) vaccine Vimkunya","authors":"Kerstin Kling , Annika Falman , Lisa Branke , Michael Ramharter , Camilla Rothe , Christian Schönfeld , Thomas Grünewald","doi":"10.1016/j.vaccine.2026.128251","DOIUrl":"10.1016/j.vaccine.2026.128251","url":null,"abstract":"<div><h3>Background</h3><div>Infections with the chikungunya virus are increasingly reported due to many reasons including climate change. Two vaccines against chikungunya have recently been approved in Europe, the live-attenuated vaccine (LAV) Ixchiq and the virus like particle (VLP) vaccine Vimkunya. However, no systematic review of phase 3 clinical trial data has been published that summarizes the currently available evidence on the immunogenicity, tolerability, and safety of these vaccines. Therefore, these data were systematically analyzed by a working group of the German Standing Committee on Vaccination (STIKO) and the German Society for Tropical Medicine, Travel Medicine and Global Health (DTG).</div></div><div><h3>Methods</h3><div>We conducted a systematic review of the immunogenicity, tolerability and safety of Ixchiq and Vimkunya using Embase and PubMed (OVID) according to predefined PICO criteria, including placebo-controlled randomized control trials, cohort, and case-control studies. Risk of bias (RoB) was assessed with the RoB 2-tool. Additionally, post-marketing safety data were studied.</div></div><div><h3>Results</h3><div>Clinical efficacy data were not available. Instead, seropositivity rates above a predefined threshold served as a surrogate of protection. Both vaccines demonstrated strong immunogenicity with seroprotection rates for Ixchiq of >98% after 4 weeks, and for Vimkunya after 3 weeks of >97% in 12–59-year-olds and > 87% in ≥65-year-olds. In the pivotal studies, both vaccines showed also an acceptable safety profile. Post-marketing safety data showed a higher risk for serious adverse events in elderly patients for Ixchiq.</div></div><div><h3>Conclusion</h3><div>In addition to mosquito protection and vector control, two vaccines with a good efficacy profile based on the surrogate marker of seroprotection are now available to prevent chikungunya. While both vaccines showed acceptable tolerability, the safety of vaccines must be continuously assessed based on further data from post-marketing surveillance of the respective populations.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128251"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146021054","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}
Pub Date : 2026-03-07Epub Date: 2026-01-20DOI: 10.1016/j.vaccine.2026.128249
Darlington David Faijue , Oumnia Bouaddi , Kathryn Mackey , Anna Deal , Erva Nur Cinar , Beatriz Morais , Sainabou Bojang , Isra Al-Sharabi , Holly Seale , Agnes Ssali , Kirsty Le Doare , Sally Hargreaves
<div><h3>Background</h3><div>Catch-up vaccination helps close immunity gaps among migrants, refugees and internally displaced people (IDPs) in low- and middle-income countries (LMICs). Despite immunisation life-course policies and global guidelines promoting catch-up vaccination of arriving migrants, vaccination strategies for adolescent and adult populations are poorly described. We synthesised evidence on catch-up vaccination strategies and interventions, delivery platforms, uptake and coverage, and contextual barriers and enablers in LMICs.</div></div><div><h3>Methods</h3><div>We searched Embase, Medline, PsycINFO, Global Health, Web of Science and grey literature sources (including websites of international and national public health organisations and agencies) for primary studies and reports on catch-up vaccination strategies and interventions, delivery platforms, uptake and coverage, and contextual barriers and enablers targeting adolescents (9–18 years) and, or adults (≥19 years) in migrants (foreign-born, including refugees) and internally displaced people (IDPs; displaced within national borders) across 136 LMICs, (from January 1st 2000 to February 1st 2025; all languages). Study quality was accessed using ROBINS-I, CASP, AACODS and, AGREE II tools.</div></div><div><h3>Results</h3><div>Thirty-seven records met the inclusion criteria (13 peer-reviewed, 24 grey literature), reporting catch-up vaccination activities across 16 LMICs. Most studies were conducted in Uganda (<em>n</em> = 6), Bangladesh (<em>n</em> = 4), Lebanon (<em>n</em> = 3), and Kenya (<em>n</em> = 3). Interventions reached ≥48,000 migrants, refugees, and IDPs (primarily Rohingya refugees in Bangladesh during COVID-19 catch-up campaigns). Populations targeted included mostly refugees (<em>n</em> = 16 studies; 43.2%), general migrants (<em>n</em> = 14; 37.8%), and IDPs (<em>n</em> = 5; 13.5%), with a smaller number involving mixed or other migrant groups (n = 4; 10.8%). The most frequently delivered vaccines were measles-rubella (<em>n</em> = 12; 32.4%), COVID-19 primary-series catch-up (<em>n</em> = 9; 24.3%), HPV (<em>n</em> = 6; 16.2%), polio OPV/IPV (<em>n</em> = 5; 13.5%), and Hepatitis B (n = 3; 8.1%). Catch-up vaccine delivery most commonly occurred through primary care via opportunistic offers (<em>n</em> = 11) and mobile/outreach delivery (n = 11), with additional implementation in fixed posts in camps/settlements (<em>n</em> = 7), supplemental immunisation activities (SIAs) (n = 6), school-linked delivery (n = 5), and hospital/outpatient opportunistic vaccination (<em>n</em> = 4). High uptake (≥85%) was reported where access barriers were minimised (e.g., walk-in availability, extended hours) was paired with community or peer engagement and simple recall systems (SMS or e-booking). Reported barriers included documentation/entitlement checks, language barriers, and fragmented or non-interoperable vaccination records.</div></div><div><h3>Conclusions</h3><div>Migrants
{"title":"Strategies, interventions, and uptake of catch-up vaccination among adolescent and adult migrants, refugees, and internally displaced persons (IDPs) in low- and middle-income countries (LMICs): A systematic review","authors":"Darlington David Faijue , Oumnia Bouaddi , Kathryn Mackey , Anna Deal , Erva Nur Cinar , Beatriz Morais , Sainabou Bojang , Isra Al-Sharabi , Holly Seale , Agnes Ssali , Kirsty Le Doare , Sally Hargreaves","doi":"10.1016/j.vaccine.2026.128249","DOIUrl":"10.1016/j.vaccine.2026.128249","url":null,"abstract":"<div><h3>Background</h3><div>Catch-up vaccination helps close immunity gaps among migrants, refugees and internally displaced people (IDPs) in low- and middle-income countries (LMICs). Despite immunisation life-course policies and global guidelines promoting catch-up vaccination of arriving migrants, vaccination strategies for adolescent and adult populations are poorly described. We synthesised evidence on catch-up vaccination strategies and interventions, delivery platforms, uptake and coverage, and contextual barriers and enablers in LMICs.</div></div><div><h3>Methods</h3><div>We searched Embase, Medline, PsycINFO, Global Health, Web of Science and grey literature sources (including websites of international and national public health organisations and agencies) for primary studies and reports on catch-up vaccination strategies and interventions, delivery platforms, uptake and coverage, and contextual barriers and enablers targeting adolescents (9–18 years) and, or adults (≥19 years) in migrants (foreign-born, including refugees) and internally displaced people (IDPs; displaced within national borders) across 136 LMICs, (from January 1st 2000 to February 1st 2025; all languages). Study quality was accessed using ROBINS-I, CASP, AACODS and, AGREE II tools.</div></div><div><h3>Results</h3><div>Thirty-seven records met the inclusion criteria (13 peer-reviewed, 24 grey literature), reporting catch-up vaccination activities across 16 LMICs. Most studies were conducted in Uganda (<em>n</em> = 6), Bangladesh (<em>n</em> = 4), Lebanon (<em>n</em> = 3), and Kenya (<em>n</em> = 3). Interventions reached ≥48,000 migrants, refugees, and IDPs (primarily Rohingya refugees in Bangladesh during COVID-19 catch-up campaigns). Populations targeted included mostly refugees (<em>n</em> = 16 studies; 43.2%), general migrants (<em>n</em> = 14; 37.8%), and IDPs (<em>n</em> = 5; 13.5%), with a smaller number involving mixed or other migrant groups (n = 4; 10.8%). The most frequently delivered vaccines were measles-rubella (<em>n</em> = 12; 32.4%), COVID-19 primary-series catch-up (<em>n</em> = 9; 24.3%), HPV (<em>n</em> = 6; 16.2%), polio OPV/IPV (<em>n</em> = 5; 13.5%), and Hepatitis B (n = 3; 8.1%). Catch-up vaccine delivery most commonly occurred through primary care via opportunistic offers (<em>n</em> = 11) and mobile/outreach delivery (n = 11), with additional implementation in fixed posts in camps/settlements (<em>n</em> = 7), supplemental immunisation activities (SIAs) (n = 6), school-linked delivery (n = 5), and hospital/outpatient opportunistic vaccination (<em>n</em> = 4). High uptake (≥85%) was reported where access barriers were minimised (e.g., walk-in availability, extended hours) was paired with community or peer engagement and simple recall systems (SMS or e-booking). Reported barriers included documentation/entitlement checks, language barriers, and fragmented or non-interoperable vaccination records.</div></div><div><h3>Conclusions</h3><div>Migrants","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128249"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146021097","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}
Pub Date : 2026-03-07Epub Date: 2026-01-19DOI: 10.1016/j.vaccine.2026.128243
Bo Wu , Tao Cheng , Yanyang Zhang , Kezhong A , Zhiyuan Hou , Xiaohua Ying , Chaowei Fu
Objectives
To assess pertussis vaccination intentions and identify key vaccine attribute preferences among Chinese adolescents, adults and pregnant women to inform future pertussis immunisation strategies.
Methods
We conducted a cross-sectional survey using multistage stratified cluster random sampling across five provinces selected to capture geographic and socioeconomic diversity in China. Participants included adolescents aged 15–17 years, adults, and pregnant women. Prior to the DCE component, all respondents received a brief, standardised description of pertussis and pertussis vaccination to ensure a minimum level of understanding. Correlates of intention were examined using multivariable logistic regression and causal mediation analysis. A discrete choice experiment (DCE) varied efficacy, adverse events following immunisation (AEFI), duration, origin and cost, with willingness-to-pay (WTP) estimated via mixed logit models. Subgroup heterogeneity was assessed by demographic and cognitive characteristics.
Results
Respondents expressed generally high vaccination intention. Among adolescents and adults, larger household size was associated with higher intention; among pregnant women, primiparity was associated with lower intention. Pertussis knowledge partially mediated the education–intention association. In the DCE, all attributes except duration influenced choices, with efficacy the dominant driver; lower AEFI risk, domestically produced vaccines, and lower cost increased preference. Pregnant women showed higher WTP than adults. Preferences varied across demographic and cognitive subgroups.
Conclusions
Respondents showed sizeable intention and consistent preferences for efficacy, safety and affordability, especially for domestically produced vaccines, informing programme design through targeted risk communication, willingness-to-pay–aligned pricing and integration within antenatal services to support real-world uptake.
{"title":"Adult and maternal pertussis vaccination in China: intention, preferences, and pricing implications from a discrete choice experiment","authors":"Bo Wu , Tao Cheng , Yanyang Zhang , Kezhong A , Zhiyuan Hou , Xiaohua Ying , Chaowei Fu","doi":"10.1016/j.vaccine.2026.128243","DOIUrl":"10.1016/j.vaccine.2026.128243","url":null,"abstract":"<div><h3>Objectives</h3><div>To assess pertussis vaccination intentions and identify key vaccine attribute preferences among Chinese adolescents, adults and pregnant women to inform future pertussis immunisation strategies.</div></div><div><h3>Methods</h3><div>We conducted a cross-sectional survey using multistage stratified cluster random sampling across five provinces selected to capture geographic and socioeconomic diversity in China. Participants included adolescents aged 15–17 years, adults, and pregnant women. Prior to the DCE component, all respondents received a brief, standardised description of pertussis and pertussis vaccination to ensure a minimum level of understanding. Correlates of intention were examined using multivariable logistic regression and causal mediation analysis. A discrete choice experiment (DCE) varied efficacy, adverse events following immunisation (AEFI), duration, origin and cost, with willingness-to-pay (WTP) estimated via mixed logit models. Subgroup heterogeneity was assessed by demographic and cognitive characteristics.</div></div><div><h3>Results</h3><div>Respondents expressed generally high vaccination intention. Among adolescents and adults, larger household size was associated with higher intention; among pregnant women, primiparity was associated with lower intention. Pertussis knowledge partially mediated the education–intention association. In the DCE, all attributes except duration influenced choices, with efficacy the dominant driver; lower AEFI risk, domestically produced vaccines, and lower cost increased preference. Pregnant women showed higher WTP than adults. Preferences varied across demographic and cognitive subgroups.</div></div><div><h3>Conclusions</h3><div>Respondents showed sizeable intention and consistent preferences for efficacy, safety and affordability, especially for domestically produced vaccines, informing programme design through targeted risk communication, willingness-to-pay–aligned pricing and integration within antenatal services to support real-world uptake.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128243"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014041","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}
Pub Date : 2026-03-07Epub Date: 2026-01-17DOI: 10.1016/j.vaccine.2026.128228
Tafadzwa Dzinamarira , Oscar Mano , Godfrey Musuka , Roda Madziva , Noah Mataruse , Elliot Mbunge , Sphamandla Josias Nkambule , Enos Moyo
Background
Despite global progress in childhood immunization, Sub-Saharan Africa (SSA) continues to report suboptimal coverage and high under-five mortality. This systematic review and meta-analysis assessed the prevalence and determinants of full immunization among children under five in SSA between 2013 and 2025.
Methods
We systematically searched six electronic databases for studies published between January 2013 and May 2025 that reported the prevalence and/or determinants of full immunization in SSA. Eligible studies were original, peer-reviewed quantitative research. Data were analysed using random-effects meta-analysis, with subgroup and sensitivity analyses conducted to explore heterogeneity. Determinants were synthesised using pooled odds ratios (ORs) where applicable.
Results
Thirty-one studies comprising 299,898 children were included. The pooled prevalence of full immunization was 51% (95% CI: 45%–58%), with substantial heterogeneity (I2 = 100%). Prevalence varied widely across studies from 6% to 96%. Subgroup analyses revealed lower coverage in recent years and in studies with larger sample sizes. Key positive determinants of full immunization included maternal education (OR = 2.70), paternal education (OR = 2.48), antenatal care attendance (OR = 0.23 for non-attendance), institutional delivery (OR = 2.99), and household wealth (OR = 2.45). Children in rural areas (OR = 0.55) and those with mothers of higher parity (OR = 0.67) were less likely to be fully immunised.
Conclusion
Full immunization coverage in SSA remains well below global targets, with wide disparities by country, socioeconomic status, and maternal healthcare utilization. Strengthening maternal health services, improving education, and addressing health system barriers are critical to improving coverage and reducing preventable child deaths in the region.
{"title":"Prevalence and determinants of full immunization among children under five in sub-Saharan Africa: A systematic review and meta-analysis (2013–2025)","authors":"Tafadzwa Dzinamarira , Oscar Mano , Godfrey Musuka , Roda Madziva , Noah Mataruse , Elliot Mbunge , Sphamandla Josias Nkambule , Enos Moyo","doi":"10.1016/j.vaccine.2026.128228","DOIUrl":"10.1016/j.vaccine.2026.128228","url":null,"abstract":"<div><h3>Background</h3><div>Despite global progress in childhood immunization, Sub-Saharan Africa (SSA) continues to report suboptimal coverage and high under-five mortality. This systematic review and meta-analysis assessed the prevalence and determinants of full immunization among children under five in SSA between 2013 and 2025.</div></div><div><h3>Methods</h3><div>We systematically searched six electronic databases for studies published between January 2013 and May 2025 that reported the prevalence and/or determinants of full immunization in SSA. Eligible studies were original, peer-reviewed quantitative research. Data were analysed using random-effects meta-analysis, with subgroup and sensitivity analyses conducted to explore heterogeneity. Determinants were synthesised using pooled odds ratios (ORs) where applicable.</div></div><div><h3>Results</h3><div>Thirty-one studies comprising 299,898 children were included. The pooled prevalence of full immunization was 51% (95% CI: 45%–58%), with substantial heterogeneity (I<sup>2</sup> = 100%). Prevalence varied widely across studies from 6% to 96%. Subgroup analyses revealed lower coverage in recent years and in studies with larger sample sizes. Key positive determinants of full immunization included maternal education (OR = 2.70), paternal education (OR = 2.48), antenatal care attendance (OR = 0.23 for non-attendance), institutional delivery (OR = 2.99), and household wealth (OR = 2.45). Children in rural areas (OR = 0.55) and those with mothers of higher parity (OR = 0.67) were less likely to be fully immunised.</div></div><div><h3>Conclusion</h3><div>Full immunization coverage in SSA remains well below global targets, with wide disparities by country, socioeconomic status, and maternal healthcare utilization. Strengthening maternal health services, improving education, and addressing health system barriers are critical to improving coverage and reducing preventable child deaths in the region.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128228"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981900","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}
Pub Date : 2026-03-07Epub Date: 2026-01-22DOI: 10.1016/j.vaccine.2025.128187
Robyn Stuart , Nicolas Theopold , Naomi Miall , Emily Kobayashi , Sara Vernam , Tanjila Taskin , Peter M. Dull
Background
Over 2023 and 2024, 19 of the countries that were supported by Gavi to purchase HPV vaccines adopted a single-dose HPV vaccination schedule. The goal of this study is to estimate the impact on vaccination access and the number of cervical cancers averted compared to a two-dose schedule.
Methods
We estimated the population that could be targeted in countries supported by Gavi to purchase HPV vaccines. We used UNICEF shipment plans to identify the number of HPV doses shipped to each country in 2023 and 2024, plus information supplied by Gavi on the dose schedule implemented in each country and year, adjusting for vaccine wastage. We computed the number of girls that could have been reached, first assuming complete utilization of all shipped doses under a single-dose schedule, and second assuming a counterfactual scenario where all countries would have used a 2-dose schedule. We then compared this to country-reported data on the number of girls actually vaccinated. For each of the three scenarios we modeled the number of cervical cancers averted using HPVsim, a microsimulation model calibrated to each country.
Findings
We calculate that the introduction of single-dose HPV vaccination in Gavi-supported countries would have allowed these countries to target 23.3M additional girls if all supply was utilized. Reported data on girls vaccinated indicates that in actuality an additional 18.5M girls were reached due to adoption of single-dose. We estimate that the use of single-dose schedule in 2023 and 2024 could have averted up to 370,000 (356,000–376,000) additional future cervical cancers if all supply had been utilized, and 297,000 (222,000–369,000) given actual utilization.
Interpretation
The single-dose HPV vaccination strategy has had a substantial positive impact on cervical cancer elimination in context of supply constraints affecting low and middle-income countries.
{"title":"The role of HPV single-dose vaccination in expanding access in GAVI-supported countries during a period of supply constraints","authors":"Robyn Stuart , Nicolas Theopold , Naomi Miall , Emily Kobayashi , Sara Vernam , Tanjila Taskin , Peter M. Dull","doi":"10.1016/j.vaccine.2025.128187","DOIUrl":"10.1016/j.vaccine.2025.128187","url":null,"abstract":"<div><h3>Background</h3><div>Over 2023 and 2024, 19 of the countries that were supported by Gavi to purchase HPV vaccines adopted a single-dose HPV vaccination schedule. The goal of this study is to estimate the impact on vaccination access and the number of cervical cancers averted compared to a two-dose schedule.</div></div><div><h3>Methods</h3><div>We estimated the population that could be targeted in countries supported by Gavi to purchase HPV vaccines. We used UNICEF shipment plans to identify the number of HPV doses shipped to each country in 2023 and 2024, plus information supplied by Gavi on the dose schedule implemented in each country and year, adjusting for vaccine wastage. We computed the number of girls that could have been reached, first assuming complete utilization of all shipped doses under a single-dose schedule, and second assuming a counterfactual scenario where all countries would have used a 2-dose schedule. We then compared this to country-reported data on the number of girls actually vaccinated. For each of the three scenarios we modeled the number of cervical cancers averted using HPVsim, a microsimulation model calibrated to each country.</div></div><div><h3>Findings</h3><div>We calculate that the introduction of single-dose HPV vaccination in Gavi-supported countries would have allowed these countries to target 23.3M additional girls if all supply was utilized. Reported data on girls vaccinated indicates that in actuality an additional 18.5M girls were reached due to adoption of single-dose. We estimate that the use of single-dose schedule in 2023 and 2024 could have averted up to 370,000 (356,000–376,000) additional future cervical cancers if all supply had been utilized, and 297,000 (222,000–369,000) given actual utilization.</div></div><div><h3>Interpretation</h3><div>The single-dose HPV vaccination strategy has had a substantial positive impact on cervical cancer elimination in context of supply constraints affecting low and middle-income countries.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"75 ","pages":"Article 128187"},"PeriodicalIF":4.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038943","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}
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