Pub Date : 2025-11-19DOI: 10.1016/j.jvacx.2025.100756
Madeleine Mant , Armughan Islam , Andrew Prine
Introduction
The SARS-CoV-2 pandemic and recent measles outbreaks have brought the topic of vaccine hesitancy to the forefront of the public imagination. This research sought to understand Canadian polio survivors' perceptions of vaccines and vaccine hesitancy.
Material and methods
We interviewed 65 individuals with post-polio syndrome and used NVivo to code the qualitative descriptive analysis.
Results
Participants expressed worry regarding the declining rates of childhood vaccine acceptance. All participants championed the polio vaccine and encouraged its universal uptake. Some vaccines (e.g., MMR, diphtheria) were consistently accepted as beneficial. While most interviewees accepted the COVID-19 vaccine, a minority expressed hesitancy. Participants expressed a willingness to share their polio stories to encourage childhood vaccine uptake.
Conclusions
Polio survivors are an aging population with lived experience regarding vaccine-preventable disease. Future public health campaigns regarding vaccine uptake should endeavour to include structured engagement with post-polio support groups across Canada and internationally as community vaccine champions. Importantly, vaccine acceptance should be considered as a spectrum, and primary care physicians should be encouraged to review vaccine safety for all vaccines even with patients who express general acceptance.
{"title":"Polio survivors' perspectives on vaccine hesitancy: a qualitative interview study","authors":"Madeleine Mant , Armughan Islam , Andrew Prine","doi":"10.1016/j.jvacx.2025.100756","DOIUrl":"10.1016/j.jvacx.2025.100756","url":null,"abstract":"<div><h3>Introduction</h3><div>The SARS-CoV-2 pandemic and recent measles outbreaks have brought the topic of vaccine hesitancy to the forefront of the public imagination. This research sought to understand Canadian polio survivors' perceptions of vaccines and vaccine hesitancy.</div></div><div><h3>Material and methods</h3><div>We interviewed 65 individuals with post-polio syndrome and used NVivo to code the qualitative descriptive analysis.</div></div><div><h3>Results</h3><div>Participants expressed worry regarding the declining rates of childhood vaccine acceptance. All participants championed the polio vaccine and encouraged its universal uptake. Some vaccines (e.g., MMR, diphtheria) were consistently accepted as beneficial. While most interviewees accepted the COVID-19 vaccine, a minority expressed hesitancy. Participants expressed a willingness to share their polio stories to encourage childhood vaccine uptake.</div></div><div><h3>Conclusions</h3><div>Polio survivors are an aging population with lived experience regarding vaccine-preventable disease. Future public health campaigns regarding vaccine uptake should endeavour to include structured engagement with post-polio support groups across Canada and internationally as community vaccine champions. Importantly, vaccine acceptance should be considered as a spectrum, and primary care physicians should be encouraged to review vaccine safety for all vaccines even with patients who express general acceptance.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100756"},"PeriodicalIF":2.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-17DOI: 10.1016/j.jvacx.2025.100752
Brook Tesfaye , Julius E. Chia , Terna Nomhwange , D. Collins Owuor , Ticha Johnson Muluh , Safdar Nosheen , Arthur Yannick Doungmo Wakem , Abdullateef Jimoh , Akif Saatcioglu , Kebba Touray , Abdulahi Walla Hamisu , Modjirom Ndoutabe , Jamal A. Ahmed , Anfumbom Kfutwah
Background
The continued detection of orphan polioviruses, defined by ≥ 1.5 % nucleotide divergence in the VP1-coding region of the virus compared with the VP1 of previous circulating isolates, presents a significant challenge to polio eradication efforts. Orphan polioviruses underscores the existence of undetected transmissions and surveillance blind spots. Understanding the epidemiology and genetic characteristics of these viruses is essential to accelerate eradication efforts.
Methods
A retrospective analysis was conducted on orphan polioviruses detected in the WHO African region from 2022 to 2024, using WHO polio database. Descriptive statistics, spatial analysis, and phylogenetic methods were employed to assess virus transmission, genetic diversity, and surveillance system performance.
Results
A total of 130 orphan polioviruses were detected within the study period in 17 countries, with Nigeria and Chad accounting for 69 % of all reported orphan polioviruses. Circulating Vaccine-derived Poliovirus type 2 (cVDPV2) was the predominant serotype, accounting for 96 % of overall detections. The majority of the orphan polioviruses were among children under-five years, with 66 % having received the recommended 3 doses of Oral Polio Vaccine (OPV). The median time to detection was 54 days (IQR: 41–72), with significant delays observed in Chad and Democratic Republic of Congo (DRC). Phylogenetic analysis revealed independent emergences and prolonged circulation. Nigeria showed high genetic diversity with at least 6 distinct sub-lineages, the predominant emergence being NIE-ZAS-1. Closely related chains of transmission were identified in Nigeria, Chad, Niger, and Cameroon, highlighting sustained cross-border transmission within the Lake Chad Basin region. Also, the detection of orphan poliovirus in Angola genetically traced to Nigeria demonstrates the risk of an even wider geographic spread.
Conclusion
The detection of orphan polioviruses and demonstration of viral genetic linkages highlights persistent surveillance and immunity gaps in the WHO African region. Improving the sensitivity of surveillance systems, expanding regional sequencing capacity, and intensifying cross-border synchronization of surveillance and immunization activities are important in the timely detection of silent transmissions and advancing eradication goals.
{"title":"Epidemiology and genetic characterization of orphan polioviruses in Africa, 2022–2024: Unmasking silent transmission and implications for eradication","authors":"Brook Tesfaye , Julius E. Chia , Terna Nomhwange , D. Collins Owuor , Ticha Johnson Muluh , Safdar Nosheen , Arthur Yannick Doungmo Wakem , Abdullateef Jimoh , Akif Saatcioglu , Kebba Touray , Abdulahi Walla Hamisu , Modjirom Ndoutabe , Jamal A. Ahmed , Anfumbom Kfutwah","doi":"10.1016/j.jvacx.2025.100752","DOIUrl":"10.1016/j.jvacx.2025.100752","url":null,"abstract":"<div><h3>Background</h3><div>The continued detection of orphan polioviruses, defined by ≥ 1.5 % nucleotide divergence in the VP1-coding region of the virus compared with the VP1 of previous circulating isolates, presents a significant challenge to polio eradication efforts. Orphan polioviruses underscores the existence of undetected transmissions and surveillance blind spots. Understanding the epidemiology and genetic characteristics of these viruses is essential to accelerate eradication efforts.</div></div><div><h3>Methods</h3><div>A retrospective analysis was conducted on orphan polioviruses detected in the WHO African region from 2022 to 2024, using WHO polio database. Descriptive statistics, spatial analysis, and phylogenetic methods were employed to assess virus transmission, genetic diversity, and surveillance system performance.</div></div><div><h3>Results</h3><div>A total of 130 orphan polioviruses were detected within the study period in 17 countries, with Nigeria and Chad accounting for 69 % of all reported orphan polioviruses. Circulating Vaccine-derived Poliovirus type 2 (cVDPV2) was the predominant serotype, accounting for 96 % of overall detections. The majority of the orphan polioviruses were among children under-five years, with 66 % having received the recommended 3 doses of Oral Polio Vaccine (OPV). The median time to detection was 54 days (IQR: 41–72), with significant delays observed in Chad and Democratic Republic of Congo (DRC). Phylogenetic analysis revealed independent emergences and prolonged circulation. Nigeria showed high genetic diversity with at least 6 distinct sub-lineages, the predominant emergence being NIE-ZAS-1. Closely related chains of transmission were identified in Nigeria, Chad, Niger, and Cameroon, highlighting sustained cross-border transmission within the Lake Chad Basin region. Also, the detection of orphan poliovirus in Angola genetically traced to Nigeria demonstrates the risk of an even wider geographic spread.</div></div><div><h3>Conclusion</h3><div>The detection of orphan polioviruses and demonstration of viral genetic linkages highlights persistent surveillance and immunity gaps in the WHO African region. Improving the sensitivity of surveillance systems, expanding regional sequencing capacity, and intensifying cross-border synchronization of surveillance and immunization activities are important in the timely detection of silent transmissions and advancing eradication goals.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100752"},"PeriodicalIF":2.2,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-16DOI: 10.1016/j.jvacx.2025.100754
Arun Dahil, David Hardisty, Glenn Simpson, Hajira Dambha-Miller
Background
Vaccination rates vary in the UK population but are vital in maintaining public health. Social care needs (SCN) refer to the promotion of independence and wellbeing, particularly in those who may have a disability, be socially isolated, or endure economic stress. Variations in SCN may impact vaccine uptake, thereby affecting vaccination coverage, but this is poorly understood.
Aim
We aim in our study to collate and interpret existing evidence on the variations in vaccination coverage among individuals with SCN.
Methods
Searches were conducted using Medline, Embase, Cochrane, CINAHL, and Bielefeld Academic Search Engine (BASE) from inception to June 27, 2024. Grey literature was also searched. Two authors independently screened and extracted relevant papers, with disagreements resolved by a third author. The search terms used included: “vaccination AND social need AND immunisation”, and variations of these terms.
Results
We identified 606 articles with 32 meeting the inclusion criteria following full-text screening. Studies originated from various regions, with most conducted in the USA. Key SCN identified as barriers to vaccination included access issues, limited information, social vulnerability, and economic deprivation. Vaccines most affected included influenza, pneumonia, and HPV.
Conclusions
Our review collated evidence on vaccination uptake variations in relation to SCN, finding a limited body of research, primarily from the USA. Most studies indicated lower vaccine uptake among individuals with SCN. Greater understanding of these variations could inform improved vaccination uptake, especially in high-risk groups. Further research is needed to identify effective interventions to address these disparities in vaccination coverage.
英国人口的疫苗接种率各不相同，但对维护公众健康至关重要。社会关怀需求（Social care needs， SCN）是指促进独立和福祉，特别是那些可能有残疾、被社会孤立或承受经济压力的人。SCN的变化可能会影响疫苗的摄取，从而影响疫苗接种的覆盖率，但这一点尚不清楚。在我们的研究中，我们的目的是整理和解释SCN个体中疫苗接种覆盖率变化的现有证据。方法使用Medline、Embase、Cochrane、CINAHL和Bielefeld学术搜索引擎（BASE）进行检索，检索时间自成立至2024年6月27日。灰色文献也被检索。两位作者独立筛选和提取相关论文，分歧由第三位作者解决。使用的搜索词包括：“疫苗接种和社会需求和免疫接种”，以及这些词的变体。结果通过全文筛选，共纳入606篇文献，其中32篇符合纳入标准。研究来自不同地区，其中大多数在美国进行。被确定为疫苗接种障碍的关键SCN包括获取问题、信息有限、社会脆弱性和经济剥夺。受影响最大的疫苗包括流感、肺炎和人乳头瘤病毒。我们的综述整理了疫苗摄取变化与SCN相关的证据，发现主要来自美国的有限研究机构。大多数研究表明，SCN患者的疫苗接种率较低。更好地了解这些变异可以提高疫苗接种率，特别是在高危人群中。需要进一步研究确定有效的干预措施，以解决疫苗接种覆盖率方面的这些差异。
{"title":"Variations in vaccination coverage by social care need: a scoping review","authors":"Arun Dahil, David Hardisty, Glenn Simpson, Hajira Dambha-Miller","doi":"10.1016/j.jvacx.2025.100754","DOIUrl":"10.1016/j.jvacx.2025.100754","url":null,"abstract":"<div><h3>Background</h3><div>Vaccination rates vary in the UK population but are vital in maintaining public health. Social care needs (SCN) refer to the promotion of independence and wellbeing, particularly in those who may have a disability, be socially isolated, or endure economic stress. Variations in SCN may impact vaccine uptake, thereby affecting vaccination coverage, but this is poorly understood.</div></div><div><h3>Aim</h3><div>We aim in our study to collate and interpret existing evidence on the variations in vaccination coverage among individuals with SCN.</div></div><div><h3>Methods</h3><div>Searches were conducted using Medline, Embase, Cochrane, CINAHL, and Bielefeld Academic Search Engine (BASE) from inception to June 27, 2024. Grey literature was also searched. Two authors independently screened and extracted relevant papers, with disagreements resolved by a third author. The search terms used included: “vaccination AND social need AND immunisation”, and variations of these terms.</div></div><div><h3>Results</h3><div>We identified 606 articles with 32 meeting the inclusion criteria following full-text screening. Studies originated from various regions, with most conducted in the USA. Key SCN identified as barriers to vaccination included access issues, limited information, social vulnerability, and economic deprivation. Vaccines most affected included influenza, pneumonia, and HPV.</div></div><div><h3>Conclusions</h3><div>Our review collated evidence on vaccination uptake variations in relation to SCN, finding a limited body of research, primarily from the USA. Most studies indicated lower vaccine uptake among individuals with SCN. Greater understanding of these variations could inform improved vaccination uptake, especially in high-risk groups. Further research is needed to identify effective interventions to address these disparities in vaccination coverage.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100754"},"PeriodicalIF":2.2,"publicationDate":"2025-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1016/j.jvacx.2025.100755
Penda Johm, Mbasan M. Jallow, Ebrima Manneh, Ed Clarke
Introduction/background
Human papillomavirus (HPV) is one of the most common sexually transmitted infections associated with cervical cancer. In The Gambia, it is estimated that 770,927 women aged 15 years and above are at risk of cervical cancer with approximately 286 new cases being diagnosed annually. Despite the effectiveness of the HPV vaccine, uptake has remained low since its introduction in 2019. This qualitative study explored the potential impact of age (adults versus adolescents versus infants) and gender (boys and girls versus girls only) on caregivers' acceptance of the HPV vaccine. Understanding caregivers' reasons for acceptance and refusal can help HPV vaccine programme managers to address issues that may prevent uptake.
Methods
23 qualitative in-depth interviews and 10 focus group discussions with a total of 83 caregivers were conducted in urban and rural settlements located across five regions of the Gambia (West Coast, North Bank, Lower River, Central River and Upper River). Male and female caregivers aged 18 and above were recruited through convenience and snowball sampling. NVivo 14 qualitative data analysis software was used for data management and thematic analysis.
Results
Knowledge of HPV, cervical cancer, and the HPV vaccine was scarce. Participants highlighted the need for greater sensitisation on HPV and the vaccine. Despite this, all participants accepted the HPV vaccine regardless of the age or gender of the individual receiving the vaccine. Motives for vaccine acceptance included ensuring the wellbeing of their children and trust in healthcare workers. Vaccine hesitancy was prompted by a lack of sensitisation and fear of infertility.
Conclusion
HPV vaccine acceptance is high across the different regions although there is a need for widespread sensitisation. Such findings can inform the implementation of future vaccination programmes to improve sensitization messaging, plan for effective vaccination rollout and subsequently increase uptake and coverage of HPV vaccines.
{"title":"Primary caregivers' acceptance of gendered human papillomavirus (HPV) vaccination across The Gambia","authors":"Penda Johm, Mbasan M. Jallow, Ebrima Manneh, Ed Clarke","doi":"10.1016/j.jvacx.2025.100755","DOIUrl":"10.1016/j.jvacx.2025.100755","url":null,"abstract":"<div><h3>Introduction/background</h3><div>Human papillomavirus (HPV) is one of the most common sexually transmitted infections associated with cervical cancer. In The Gambia, it is estimated that 770,927 women aged 15 years and above are at risk of cervical cancer with approximately 286 new cases being diagnosed annually. Despite the effectiveness of the HPV vaccine, uptake has remained low since its introduction in 2019. This qualitative study explored the potential impact of age (adults versus adolescents versus infants) and gender (boys and girls versus girls only) on caregivers' acceptance of the HPV vaccine. Understanding caregivers' reasons for acceptance and refusal can help HPV vaccine programme managers to address issues that may prevent uptake.</div></div><div><h3>Methods</h3><div>23 qualitative in-depth interviews and 10 focus group discussions with a total of 83 caregivers were conducted in urban and rural settlements located across five regions of the Gambia (West Coast, North Bank, Lower River, Central River and Upper River). Male and female caregivers aged 18 and above were recruited through convenience and snowball sampling. NVivo 14 qualitative data analysis software was used for data management and thematic analysis.</div></div><div><h3>Results</h3><div>Knowledge of HPV, cervical cancer, and the HPV vaccine was scarce. Participants highlighted the need for greater sensitisation on HPV and the vaccine. Despite this, all participants accepted the HPV vaccine regardless of the age or gender of the individual receiving the vaccine. Motives for vaccine acceptance included ensuring the wellbeing of their children and trust in healthcare workers. Vaccine hesitancy was prompted by a lack of sensitisation and fear of infertility.</div></div><div><h3>Conclusion</h3><div>HPV vaccine acceptance is high across the different regions although there is a need for widespread sensitisation. Such findings can inform the implementation of future vaccination programmes to improve sensitization messaging, plan for effective vaccination rollout and subsequently increase uptake and coverage of HPV vaccines.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100755"},"PeriodicalIF":2.2,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-11DOI: 10.1016/j.jvacx.2025.100750
Tarsizio Chikaonda , Morrison P. Kamanga , Faith Thole , Bridgette Galafa , Glory Kadzanja , Belson Kutambe , Mavis Menyere , Phillip M. Ashton , Ashleigh Howard , Daniela M. Ferreira , Kondwani Jambo , Stephen B. Gordon
Background
Controlled Human Infection Models (CHIM) are an important tool in biomedical research in which pathogens are inoculated into human volunteers to study pathogenesis and test vaccines or treatments. Production of CHIM inoculum, however, presents specific challenges in safety, reproducibility and replication of the desired dose. The principles of Good Manufacturing Practice (GMP) developed for production of medications can be applied to the preparation of CHIM inocula, but licensed GMP facilities are scarce in low resource settings.
Methods
We applied GMP principles to develop protocols for CHIM inocula production at Liverpool School of Tropical Medicine, UK and subsequently at Malawi-Liverpool Wellcome Programme, Malawi. We used published guidelines to evaluate these protocols and to advise selection, characterisation, manufacture, quality control and storage. We established in-house production of Streptococcus pneumoniae serotypes 3 and 6B for use in Experimental Human Pneumococcal Challenge models.
Results
The manufacturing process underwent regulatory review in both the UK and Malawi. CHIM inocula production in Malawi was approved by the National Health Sciences Research Committee after written and oral submission. We successfully implemented our procedure and manufactured batch lots of Streptococcus pneumoniae serotype 3 (n = 2) and serotype 6B (n = 2). We safely, accurately and successfully inoculated participants in CHIM studies and achieved experimental human pneumococcal carriage with both serotype strains.
Discussion
CHIM inoculum manufacture of pneumococcus was feasible in Malawi. This allowed the Malawi scientific ecosystem to demonstrate scientific and regulatory autonomy as well as having the potential to improve operational efficiency compared to importation of challenge agents.
{"title":"Controlled human infection model (CHIM) inoculum production in Malawi using principles of good manufacturing practice","authors":"Tarsizio Chikaonda , Morrison P. Kamanga , Faith Thole , Bridgette Galafa , Glory Kadzanja , Belson Kutambe , Mavis Menyere , Phillip M. Ashton , Ashleigh Howard , Daniela M. Ferreira , Kondwani Jambo , Stephen B. Gordon","doi":"10.1016/j.jvacx.2025.100750","DOIUrl":"10.1016/j.jvacx.2025.100750","url":null,"abstract":"<div><h3>Background</h3><div>Controlled Human Infection Models (CHIM) are an important tool in biomedical research in which pathogens are inoculated into human volunteers to study pathogenesis and test vaccines or treatments. Production of CHIM inoculum, however, presents specific challenges in safety, reproducibility and replication of the desired dose. The principles of Good Manufacturing Practice (GMP) developed for production of medications can be applied to the preparation of CHIM inocula, but licensed GMP facilities are scarce in low resource settings.</div></div><div><h3>Methods</h3><div>We applied GMP principles to develop protocols for CHIM inocula production at Liverpool School of Tropical Medicine, UK and subsequently at Malawi-Liverpool Wellcome Programme, Malawi. We used published guidelines to evaluate these protocols and to advise selection, characterisation, manufacture, quality control and storage. We established in-house production of <em>Streptococcus pneumoniae</em> serotypes 3 and 6B for use in Experimental Human Pneumococcal Challenge models.</div></div><div><h3>Results</h3><div>The manufacturing process underwent regulatory review in both the UK and Malawi. CHIM inocula production in Malawi was approved by the National Health Sciences Research Committee after written and oral submission. We successfully implemented our procedure and manufactured batch lots of <em>Streptococcus pneumoniae</em> serotype 3 (<em>n</em> = 2) and serotype 6B (n = 2). We safely, accurately and successfully inoculated participants in CHIM studies and achieved experimental human pneumococcal carriage with both serotype strains.</div></div><div><h3>Discussion</h3><div>CHIM inoculum manufacture of pneumococcus was feasible in Malawi. This allowed the Malawi scientific ecosystem to demonstrate scientific and regulatory autonomy as well as having the potential to improve operational efficiency compared to importation of challenge agents.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100750"},"PeriodicalIF":2.2,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dengue vaccine Qdenga® has been available in Argentina since November 2023. This study aimed to evaluate adverse events following immunization (AEFI) in individuals vaccinated with Qdenga® in private centers in the metropolitan area of Buenos Aires.
Methods
A retrospective, observational, multicenter study was conducted through passive surveillance of AEFI in individuals ≥4-years-old who received Qdenga® from 01/Nov/2023 to 01/Nov/2024.
AEFI incidence was calculated per 1000 doses administered, stratified by dose, age group and seriousness. Associations between population characteristics and AEFI were analysed. Hypersensitivity reactions incidence was calculated.
Results
156,676 doses were administered to 112,345 individuals, mean age 36.5 years (median 40; range 4–102).
A total of 303 AEFI were reported, with an incidence rate of 1.9/1000; 2.5/1000 (277/109,281) for first dose and 0.5/1000 (26/47,395) for second dose. No statistical differences by age and higher reports in 18–60-year-old group women were observed.
AEFI classification
1-Non-serious (95.1%): the most frequent were rash (41.8%), myalgia (30.0%), pyrexia (29.2%) and headache (26.0%) after first dose; pyrexia (38.5%) and headache (26.9%) after second dose. 2-Serious (1.3%): anaphylactic reaction, nephrotic syndrome, immune thrombocytopenic purpura, and Hodgkin's lymphoma. 3-Special Situation Reports (2.6%): Five pregnant women vaccinated; one infant born with interventricular communication. Three vaccinated while breastfeeding; one infant had diarrhea. 4-Vaccine administration errors (1.0%): three cases.
Anaphylaxis and hypersensitivity non-anaphylaxis incidence: 0.006/1000 and 0.14/1000 respectively.
Conclusion
AEFI cases were more common after the first dose and mostly non-serious. No age-related association was found. This study identified few signals in passive surveillance after Qdenga® vaccine.
{"title":"Retrospective analysis of one year of passive safety surveillance data following implementation of the dengue vaccine, Qdenga® (TAK-003) at private vaccination centers, in Buenos Aires, Argentina","authors":"Vanesa Edelvais Castellano MD , Sofìa Diana Menéndez , Jimena Ochoa MD , Fernando Burgos MD , Fernando Fernadez MD , Romina Gigliotti MD , Mariano Díaz MD , Pablo Bonvehí MD","doi":"10.1016/j.jvacx.2025.100749","DOIUrl":"10.1016/j.jvacx.2025.100749","url":null,"abstract":"<div><h3>Background</h3><div>Dengue vaccine Qdenga® has been available in Argentina since November 2023. This study aimed to evaluate adverse events following immunization (AEFI) in individuals vaccinated with Qdenga® in private centers in the metropolitan area of Buenos Aires.</div></div><div><h3>Methods</h3><div>A retrospective, observational, multicenter study was conducted through passive surveillance of AEFI in individuals ≥4-years-old who received Qdenga® from 01/Nov/2023 to 01/Nov/2024.</div><div>AEFI incidence was calculated per 1000 doses administered, stratified by dose, age group and seriousness. Associations between population characteristics and AEFI were analysed. Hypersensitivity reactions incidence was calculated.</div></div><div><h3>Results</h3><div>156,676 doses were administered to 112,345 individuals, mean age 36.5 years (median 40; range 4–102).</div><div>A total of 303 AEFI were reported, with an incidence rate of 1.9/1000; 2.5/1000 (277/109,281) for first dose and 0.5/1000 (26/47,395) for second dose. No statistical differences by age and higher reports in 18–60-year-old group women were observed.</div></div><div><h3>AEFI classification</h3><div>1-Non-serious (95.1%): the most frequent were rash (41.8%), myalgia (30.0%), pyrexia (29.2%) and headache (26.0%) after first dose; pyrexia (38.5%) and headache (26.9%) after second dose. 2-Serious (1.3%): anaphylactic reaction, nephrotic syndrome, immune thrombocytopenic purpura, and Hodgkin's lymphoma. 3-Special Situation Reports (2.6%): Five pregnant women vaccinated; one infant born with interventricular communication. Three vaccinated while breastfeeding; one infant had diarrhea. 4-Vaccine administration errors (1.0%): three cases.</div><div>Anaphylaxis and hypersensitivity non-anaphylaxis incidence: 0.006/1000 and 0.14/1000 respectively.</div></div><div><h3>Conclusion</h3><div>AEFI cases were more common after the first dose and mostly non-serious. No age-related association was found. This study identified few signals in passive surveillance after Qdenga® vaccine.</div><div><strong>Clinical trial registration number:</strong> <span><span>NCT06898775</span><svg><path></path></svg></span></div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100749"},"PeriodicalIF":2.2,"publicationDate":"2025-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-07DOI: 10.1016/j.jvacx.2025.100747
Bente Smagge , Susan Hahné , Hester de Melker , Ferishta Bakhshi-Raiez , Susan van den Hof , Brechje de Gier
In the Netherlands, medical risk data and SARS-CoV-2 test results were not available for stratifying vaccine effectiveness (VE) against COVID-19 hospitalisation during the COVID-19 pandemic. Such data became available afterwards, allowing for re-estimating VE and the number needed to vaccinate (NNV) by medical risk group for severe COVID-19. We conducted a nationwide register-based cohort study, estimating VE against first-time COVID-19 hospitalisation from 06 to 01-2021 to 31-12-2021 in persons aged ≥12 years without registered prior SARS-CoV-2 infection. VE of one and two vaccinations, versus unvaccinated, were estimated by age, medical risk, vaccine type and time since vaccination using Cox models with vaccination status as time-varying exposure. Additionally, we computed the NNV to prevent one hospitalisation. Among 14.3 million individuals in this study, 43,405 COVID-19 first-time hospitalisations were recorded. VE of two doses was >80 % in the first quarter post-vaccination across all strata. VE decreased over time, but vaccination remained protective three quarters post-vaccination. Among persons aged ≥60 years without medical risk conditions, VE was 96.1 %, 91.0 % and 84.9 % in the first, second and third quarter since vaccination. VE was lower and waned faster among persons with medical risk conditions: 91.1 %, 80.0 %, 70.8 % and 85.4 %, 73.4 %, 60.6 %, in the first three quarters post-vaccination in the moderate and high medical risk groups, respectively. Nonetheless, the NNV was lower among medical risk groups. These findings suggest that prioritising medical risk populations for booster vaccination was warranted. To adequately respond to future epidemics and optimise vaccination programmes, the data infrastructure should allow near-real-time stratified VE analyses.
{"title":"COVID-19 vaccine effectiveness against hospitalisation in the Netherlands, 2021: Improved stratified estimates","authors":"Bente Smagge , Susan Hahné , Hester de Melker , Ferishta Bakhshi-Raiez , Susan van den Hof , Brechje de Gier","doi":"10.1016/j.jvacx.2025.100747","DOIUrl":"10.1016/j.jvacx.2025.100747","url":null,"abstract":"<div><div>In the Netherlands, medical risk data and SARS-CoV-2 test results were not available for stratifying vaccine effectiveness (VE) against COVID-19 hospitalisation during the COVID-19 pandemic. Such data became available afterwards, allowing for re-estimating VE and the number needed to vaccinate (NNV) by medical risk group for severe COVID-19. We conducted a nationwide register-based cohort study, estimating VE against first-time COVID-19 hospitalisation from 06 to 01-2021 to 31-12-2021 in persons aged ≥12 years without registered prior SARS-CoV-2 infection. VE of one and two vaccinations, versus unvaccinated, were estimated by age, medical risk, vaccine type and time since vaccination using Cox models with vaccination status as time-varying exposure. Additionally, we computed the NNV to prevent one hospitalisation. Among 14.3 million individuals in this study, 43,405 COVID-19 first-time hospitalisations were recorded. VE of two doses was >80 % in the first quarter post-vaccination across all strata. VE decreased over time, but vaccination remained protective three quarters post-vaccination. Among persons aged ≥60 years without medical risk conditions, VE was 96.1 %, 91.0 % and 84.9 % in the first, second and third quarter since vaccination. VE was lower and waned faster among persons with medical risk conditions: 91.1 %, 80.0 %, 70.8 % and 85.4 %, 73.4 %, 60.6 %, in the first three quarters post-vaccination in the moderate and high medical risk groups, respectively. Nonetheless, the NNV was lower among medical risk groups. These findings suggest that prioritising medical risk populations for booster vaccination was warranted. To adequately respond to future epidemics and optimise vaccination programmes, the data infrastructure should allow near-real-time stratified VE analyses.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100747"},"PeriodicalIF":2.2,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seasonal influenza vaccination is a recognized means for promoting healthy ageing. In regions like Liguria (Italy), which has the oldest population in Europe, influenza vaccination becomes even more critical. This study aimed to assess influenza vaccine effectiveness (IVE) for the prevention of hospitalization for laboratory-confirmed influenza among Ligurian adults. We conducted a retrospective test-negative case-control study in an inpatient setting, using routinely collected data. Adults (≥18 years) presenting to emergency department from November 4, 2024 through April 27, 2025, who were prescribed a molecular test for the detection of influenza virus and were subsequently hospitalized, were eligible. IVE was estimated via conditional logistic regression. In all, 173 cases and 1166 influenza-negative inpatient controls were included. Most cases were due to influenza A(H1N1)pdm09 (34 %) and A(H3N2) (59 %). In the overall population ̥≥18 years, IVE against hospitalization for any influenza virus was 47 % [95 % confidence interval (CI): 22 %, 63 %]. IVE in older adults ≥65 years was lower (43 %; 95 % CI: 14 %, 62 %) than in younger adults (76 %; 95 % CI: 5 %, 94 %). In an analysis on the effect of prior vaccination, repeat vaccinees were immunized earlier than non-repeat vaccinees. Compared to adults who were not vaccinated in either the previous or current season, those vaccinated in both seasons and current season only, were protected at 48 % (95 % CI: 19 %, 66 %) and 45 % (95 % CI, −17 %; 75 %), respectively. Influenza vaccines available for Italian adults during the 2024/2025 season provided a moderate protection against influenza-related hospitalization.
{"title":"Influenza vaccine effectiveness among Italian adult inpatients, 2024/2025 season","authors":"Alexander Domnich , Andrea Orsi , Vincenzo Paolozzi , Davide Bonassi , Giada Garzillo , Elvira Massaro , Valentina Ricucci , Matilde Ogliastro , Giancarlo Icardi","doi":"10.1016/j.jvacx.2025.100748","DOIUrl":"10.1016/j.jvacx.2025.100748","url":null,"abstract":"<div><div>Seasonal influenza vaccination is a recognized means for promoting healthy ageing. In regions like Liguria (Italy), which has the oldest population in Europe, influenza vaccination becomes even more critical. This study aimed to assess influenza vaccine effectiveness (IVE) for the prevention of hospitalization for laboratory-confirmed influenza among Ligurian adults. We conducted a retrospective test-negative case-control study in an inpatient setting, using routinely collected data. Adults (≥18 years) presenting to emergency department from November 4, 2024 through April 27, 2025, who were prescribed a molecular test for the detection of influenza virus and were subsequently hospitalized, were eligible. IVE was estimated via conditional logistic regression. In all, 173 cases and 1166 influenza-negative inpatient controls were included. Most cases were due to influenza A(H1N1)pdm09 (34 %) and A(H3N2) (59 %). In the overall population ̥≥18 years, IVE against hospitalization for any influenza virus was 47 % [95 % confidence interval (CI): 22 %, 63 %]. IVE in older adults ≥65 years was lower (43 %; 95 % CI: 14 %, 62 %) than in younger adults (76 %; 95 % CI: 5 %, 94 %). In an analysis on the effect of prior vaccination, repeat vaccinees were immunized earlier than non-repeat vaccinees. Compared to adults who were not vaccinated in either the previous or current season, those vaccinated in both seasons and current season only, were protected at 48 % (95 % CI: 19 %, 66 %) and 45 % (95 % CI, −17 %; 75 %), respectively. Influenza vaccines available for Italian adults during the 2024/2025 season provided a moderate protection against influenza-related hospitalization.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100748"},"PeriodicalIF":2.2,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-02DOI: 10.1016/j.jvacx.2025.100744
Antonio Musolino , Marco Roversi , Mariateresa Romaniello , Vittorio Scoppola , Chiara Di Camillo , Laura Celestini , Alberto Villani , Diletta Valentini
Introduction
Pneumococcal vaccination has significantly decreased the burden of invasive pneumococcal disease in the general population, however studies on effectiveness in Down syndrome (DS) are heterogeneous. In this cross-sectional study we evaluated the prevalence of adequate immune response in children with DS after pneumococcal vaccination and we searched for possible clinical predictors associated with it, in order to provide data to optimize vaccination strategies in this high-risk group.
Methods
Data of children with DS referred to the DS outpatient Clinic of Bambino Gesù Children's Hospital, Rome, Italy, between September 2021 and March 2022 were reviewed. Clinical and laboratory predictors of immunological response to PCV vaccine, defined as an anti-pneumococcal IgG titer threshold above 0.35 μg/mL were compared and evaluated with bivariate analyses and logistic regression.
Results
In this cohort of 406 patients the mean age was 8.4 years and 56.2 % of individuals were male. Most of them had congenital cardiopathy (57.8 %) and recurrent respiratory infections (57.4 %). An anti-pneumococcal Ig titer ≥0.35 μg/mL was found in 50.5 % of patients. Those with Ig < 0.35 μg/mL were significantly younger (p < 0.001) and less likely to have autoimmune disorders or hypothyroidism. Logistic regression showed that a positive history of previous surgery increased the likelihood of Ig ≥ 0.35 μg/mL (OR 2.25, p = 0.001), as well as hypothyroidism (OR 3.14, p = 0.016) and celiac disease (OR 3.70, p = 0.030). Additionally, older age at last PCV13 dose positively correlated with higher Ig levels (p = 0.018).
Conclusion
Our findings confirm a lower prevalence of adequate immune response after anti-pneumococcal vaccination in individuals with DS. Older age at last PCV13 dose was found to be correlated to higher specific IgG titers; we suggest a tailored vaccination schedule or a booster dose in individuals with DS that could improve their immune protection.
肺炎球菌疫苗接种显著降低了普通人群侵袭性肺炎球菌疾病的负担，然而，对唐氏综合征（DS）有效性的研究存在差异。在这项横断面研究中，我们评估了肺炎球菌疫苗接种后DS患儿充分免疫应答的患病率，并寻找与之相关的可能的临床预测因素，以便为优化这一高危人群的疫苗接种策略提供数据。方法回顾2021年9月至2022年3月意大利罗马Bambino Gesù儿童医院DS门诊转介的DS患儿数据。采用双变量分析和logistic回归对PCV疫苗免疫应答的临床和实验室预测因子进行了比较和评估，其定义为抗肺炎球菌IgG滴度阈值高于0.35 μg/mL。结果406例患者的平均年龄为8.4岁，56.2%为男性。以先天性心脏病（57.8%）和反复呼吸道感染（57.4%）居多。50.5%的患者抗肺炎球菌Ig滴度≥0.35 μg/mL。Ig <； 0.35 μg/mL的患者明显更年轻（p < 0.001），发生自身免疫性疾病或甲状腺功能减退的可能性更小。Logistic回归分析显示，既往手术史阳性患者Ig≥0.35 μg/mL （OR 2.25, p = 0.001）、甲状腺功能减退（OR 3.14, p = 0.016）和乳糜泻（OR 3.70, p = 0.030）的可能性增加。最后一次PCV13剂量的年龄与较高的Ig水平呈正相关（p = 0.018）。结论：我们的研究结果证实，DS患者接种抗肺炎球菌疫苗后免疫反应不足的发生率较低。PCV13最后剂量年龄越大，特异性IgG滴度越高；我们建议为退行性椎体滑移患者量身定制疫苗接种计划或加强剂量，以提高他们的免疫保护。
{"title":"Antibody response after pneumococcal vaccination in a large cohort of Italian children and adolescents with Down syndrome","authors":"Antonio Musolino , Marco Roversi , Mariateresa Romaniello , Vittorio Scoppola , Chiara Di Camillo , Laura Celestini , Alberto Villani , Diletta Valentini","doi":"10.1016/j.jvacx.2025.100744","DOIUrl":"10.1016/j.jvacx.2025.100744","url":null,"abstract":"<div><h3>Introduction</h3><div>Pneumococcal vaccination has significantly decreased the burden of invasive pneumococcal disease in the general population, however studies on effectiveness in Down syndrome (DS) are heterogeneous. In this cross-sectional study we evaluated the prevalence of adequate immune response in children with DS after pneumococcal vaccination and we searched for possible clinical predictors associated with it, in order to provide data to optimize vaccination strategies in this high-risk group.</div></div><div><h3>Methods</h3><div>Data of children with DS referred to the DS outpatient Clinic of Bambino Gesù Children's Hospital, Rome, Italy, between September 2021 and March 2022 were reviewed. Clinical and laboratory predictors of immunological response to PCV vaccine, defined as an anti-pneumococcal IgG titer threshold above 0.35 μg/mL were compared and evaluated with bivariate analyses and logistic regression.</div></div><div><h3>Results</h3><div>In this cohort of 406 patients the mean age was 8.4 years and 56.2 % of individuals were male. Most of them had congenital cardiopathy (57.8 %) and recurrent respiratory infections (57.4 %). An anti-pneumococcal Ig titer ≥0.35 μg/mL was found in 50.5 % of patients. Those with Ig < 0.35 μg/mL were significantly younger (<em>p</em> < 0.001) and less likely to have autoimmune disorders or hypothyroidism. Logistic regression showed that a positive history of previous surgery increased the likelihood of Ig ≥ 0.35 μg/mL (OR 2.25, <em>p</em> = 0.001), as well as hypothyroidism (OR 3.14, <em>p</em> = 0.016) and celiac disease (OR 3.70, <em>p</em> = 0.030). Additionally, older age at last PCV13 dose positively correlated with higher Ig levels (<em>p</em> = 0.018).</div></div><div><h3>Conclusion</h3><div>Our findings confirm a lower prevalence of adequate immune response after anti-pneumococcal vaccination in individuals with DS. Older age at last PCV13 dose was found to be correlated to higher specific IgG titers; we suggest a tailored vaccination schedule or a booster dose in individuals with DS that could improve their immune protection.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100744"},"PeriodicalIF":2.2,"publicationDate":"2025-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-28DOI: 10.1016/j.jvacx.2025.100742
Maria Lahuerta , Angel Gil , Cristina Méndez , Francisco Javier Esteban Fernández , Teresa Álvarez de Espejo , Victor Julián Moreno , Pablo del Valle , Juan E. Losa , José Yuste , Julie Catusse , Mohammad Ali , Jo Southern , Elizabeth Begier , Michael Pride , Christian Theilacker , Luis Jodar , Bradford D. Gessner , Mariana Haeberer , on behalf of the CIBELES study team
Background
Few data exist on vaccine effectiveness (VE) of the 13-valent pneumococcal conjugate vaccine (PCV13) against vaccine-type community acquired pneumonia (CAP) among adults, particularly for multiple years post-vaccination. We evaluated PCV13 VE among older adults in Spain right after the emergence of SARS-CoV2.
Methods
Adults aged ≥60 years hospitalized with CAP were enrolled at five hospitals between March 2021–September 2023. VE was assessed using a test-negative design. Cases were participants from whom PCV13 serotypes were identified from culture or urinary antigen detection assays. All others served as controls. Due to changes in healthcare-seeking behavior, hospital admission, vaccination policies, and CAP etiology during the COVID pandemic period, participants enrolled from March 2021–August 2022 were excluded from analyses.
Results
Among 1512 eligible participants, 1241 (82.1 %) were included in the analysis. Median age was 78 years (interquartile range [IQR] 72–85), 34.3 % were immunocompromised and 99.4 % had radiologically-confirmed CAP. Almost half (49.2 %) had received PCV13 of which 33.1 % were vaccinated in 2020 during the COVID-19 pandemic (median time since vaccination: 2.0 years [IQR:2.0–4.2]). Most participants (72.7 %) had previously received the pneumococcal polysaccharide vaccine (PPV23). PCV13 serotypes were identified in 89 (7.2 %) participants, most commonly serotype 3 (56 cases, 62.9 % of PCV13-type CAP). The PCV13 VE against PCV13-type CAP was 26.0 % (−15.21, 52.4 %) overall, 40.9 % (−23.1, 71.6 %) excluding serotype 3 and 51.9 % (−26.0, 81.6 %) among PPV23-naive. Among patients vaccinated <2 years before CAP hospitalization, VE against PCV13-type was 68.9 % (11.9, 89.0 %).
Conclusions
In a setting with high serotype 3 prevalence, PCV13 was highly effective in preventing PCV13-type CAP in older adults for two years after vaccination, with lower effectiveness at later time points. Given challenges associated with the pandemic and low statistical power, additional studies are indicated to evaluate serotype-specific duration of protection to inform the need for adult booster vaccinations.
{"title":"Effectiveness of the 13-valent pneumococcal vaccine against hospitalized community-acquired pneumonia among adults ≥60 years in Madrid-Spain after the COVID-19 pandemic","authors":"Maria Lahuerta , Angel Gil , Cristina Méndez , Francisco Javier Esteban Fernández , Teresa Álvarez de Espejo , Victor Julián Moreno , Pablo del Valle , Juan E. Losa , José Yuste , Julie Catusse , Mohammad Ali , Jo Southern , Elizabeth Begier , Michael Pride , Christian Theilacker , Luis Jodar , Bradford D. Gessner , Mariana Haeberer , on behalf of the CIBELES study team","doi":"10.1016/j.jvacx.2025.100742","DOIUrl":"10.1016/j.jvacx.2025.100742","url":null,"abstract":"<div><h3>Background</h3><div>Few data exist on vaccine effectiveness (VE) of the 13-valent pneumococcal conjugate vaccine (PCV13) against vaccine-type community acquired pneumonia (CAP) among adults, particularly for multiple years post-vaccination. We evaluated PCV13 VE among older adults in Spain right after the emergence of SARS-CoV2.</div></div><div><h3>Methods</h3><div>Adults aged ≥60 years hospitalized with CAP were enrolled at five hospitals between March 2021–September 2023. VE was assessed using a test-negative design. Cases were participants from whom PCV13 serotypes were identified from culture or urinary antigen detection assays. All others served as controls. Due to changes in healthcare-seeking behavior, hospital admission, vaccination policies, and CAP etiology during the COVID pandemic period, participants enrolled from March 2021–August 2022 were excluded from analyses.</div></div><div><h3>Results</h3><div>Among 1512 eligible participants, 1241 (82.1 %) were included in the analysis. Median age was 78 years (interquartile range [IQR] 72–85), 34.3 % were immunocompromised and 99.4 % had radiologically-confirmed CAP. Almost half (49.2 %) had received PCV13 of which 33.1 % were vaccinated in 2020 during the COVID-19 pandemic (median time since vaccination: 2.0 years [IQR:2.0–4.2]). Most participants (72.7 %) had previously received the pneumococcal polysaccharide vaccine (PPV23). PCV13 serotypes were identified in 89 (7.2 %) participants, most commonly serotype 3 (56 cases, 62.9 % of PCV13-type CAP). The PCV13 VE against PCV13-type CAP was 26.0 % (−15.21, 52.4 %) overall, 40.9 % (−23.1, 71.6 %) excluding serotype 3 and 51.9 % (−26.0, 81.6 %) among PPV23-naive. Among patients vaccinated <2 years before CAP hospitalization, VE against PCV13-type was 68.9 % (11.9, 89.0 %).</div></div><div><h3>Conclusions</h3><div>In a setting with high serotype 3 prevalence, PCV13 was highly effective in preventing PCV13-type CAP in older adults for two years after vaccination, with lower effectiveness at later time points. Given challenges associated with the pandemic and low statistical power, additional studies are indicated to evaluate serotype-specific duration of protection to inform the need for adult booster vaccinations.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100742"},"PeriodicalIF":2.2,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145417289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号