Developing the Zika virus (ZIKV) vaccine remains a critical global public health need. This study assessed the safety and immunogenicity of gamma-irradiated Thai ZIKV isolate. Inactivation was confirmed by serial passaging and detection of viral replication using RT-PCR, which demonstrated complete loss of infectivity in ZIKV irradiated with 25 and 50 kGy. Western blotting confirmed that irradiation preserved viral envelope protein antigenicity. BALB/c mice were subcutaneously immunized twice with 25 kGy-irradiated ZIKV, either alone or with alum adjuvant, at two-week intervals. No mortality or local reactions were observed in any group of mice. Antigen-specific IgG and neutralizing antibody titers were measured by ELISA and focus reduction neutralization test, respectively. T cell responses were assessed via intracellular IFN-γ and TNF-α staining by flow cytometry. The irradiated vaccine induced ZIKV-specific antibody and cytokine-producing T cell responses; however, neutralizing antibody titers were low. Mice immunized with irradiated ZIKV combined with alum adjuvant had higher ZIKV-specific antibody titers and T cells producing IFN-γ or TNF-α than those without adjuvant, though differences were not statistically significant. Although the viral integrity and antigenicity remained unchanged, these findings demonstrate that gamma-irradiated ZIKV is non-infectious and immunogenic in mice, supporting its safety profile and the potential for further optimization in future dose-ranging and efficacy studies.
{"title":"Safety and immunogenicity of inactivated Zika virus vaccine by gamma irradiation","authors":"Pumin Sintara , Puttawat Suphaprueksapong , Suwimol Jetawattana , Witthawat Wiriyarat , Yada Akkhawattanangkul , Komgrid Charngkaew , Nusara Chomanee , Jantip Saelee , Artit Wongsa , Thongkoon Priengprom , Boonrat Tassaneetrithep","doi":"10.1016/j.jvacx.2025.100706","DOIUrl":"10.1016/j.jvacx.2025.100706","url":null,"abstract":"<div><div>Developing the Zika virus (ZIKV) vaccine remains a critical global public health need. This study assessed the safety and immunogenicity of gamma-irradiated Thai ZIKV isolate. Inactivation was confirmed by serial passaging and detection of viral replication using RT-PCR, which demonstrated complete loss of infectivity in ZIKV irradiated with 25 and 50 kGy. Western blotting confirmed that irradiation preserved viral envelope protein antigenicity. BALB/c mice were subcutaneously immunized twice with 25 kGy-irradiated ZIKV, either alone or with alum adjuvant, at two-week intervals. No mortality or local reactions were observed in any group of mice. Antigen-specific IgG and neutralizing antibody titers were measured by ELISA and focus reduction neutralization test, respectively. T cell responses were assessed via intracellular IFN-γ and TNF-α staining by flow cytometry. The irradiated vaccine induced ZIKV-specific antibody and cytokine-producing T cell responses; however, neutralizing antibody titers were low. Mice immunized with irradiated ZIKV combined with alum adjuvant had higher ZIKV-specific antibody titers and T cells producing IFN-γ or TNF-α than those without adjuvant, though differences were not statistically significant. Although the viral integrity and antigenicity remained unchanged, these findings demonstrate that gamma-irradiated ZIKV is non-infectious and immunogenic in mice, supporting its safety profile and the potential for further optimization in future dose-ranging and efficacy studies.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"26 ","pages":"Article 100706"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863327","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 : 2025-10-01Epub Date: 2025-08-27DOI: 10.1016/j.jvacx.2025.100715
Martin Novák , Jana Zibolenová , Peter Vyšehradský , Romana Ulbrichtová , Eva Malobická , Eliška Štefanová , Ján Mikas , Adriana Mečochová , Henrieta Hudečková , Viera Švihrová
Introduction
The resurgence of vaccine-preventable diseases poses a significant global public health challenge, exacerbated by the rise of anti-vaccination attitudes. The aim of this study was to validate the Slovak version of the Vaccination Attitudes Examination (VAX) questionnaire and to examine the attitudes towards vaccination in Slovakia.
Methods
The VAX scale questionnaire, translated into Slovak and validated, was used for the survey. The VAX scale uses 12 statements assessing anti-vaccination attitudes. Each statement is scored on a 6-point Likert scale, with higher total score indicates more negative attitudes towards vaccinations. Our questionnaire also included demographic questions (age, gender, residence, education level, profession, and economic activity). For validation, the questionnaire was translated into the Slovak using forward and backward translations. The validation survey was conducted on the sample size of 115 participants. Correlation was calculated using Pearson's correlation coefficient, internal consistency was tested. Confirmatory factor analysis (CFA) was performed to assess validity. Subsequently, a pilot study was conducted in March 2023 with a sample size of 473 participants.
Results
The VAX scale demonstrated strong internal consistency (Cronbach's alpha = 0.925) and reliability. The results of the CFA were comparable to findings from other languages versions. The pilot study revealed that parents, non-healthcare professionals, and older individuals exhibited higher anti-vaccination attitudes. In contrast, healthcare professionals had the lowest VAX scores, reflecting more pro-vaccination attitudes.
Conclusion
These findings highlight the need for targeted educational and communication strategies to address vaccine hesitancy. By identifying demographic patterns and potential hotspots of vaccine skepticism, public health initiatives can be better tailored to improve vaccination rates. The validated Slovak VAX scale provides a reliable tool for ongoing assessment and intervention efforts.
{"title":"The validation of the Slovak vaccination attitudes examination (VAX) scale and pilot study","authors":"Martin Novák , Jana Zibolenová , Peter Vyšehradský , Romana Ulbrichtová , Eva Malobická , Eliška Štefanová , Ján Mikas , Adriana Mečochová , Henrieta Hudečková , Viera Švihrová","doi":"10.1016/j.jvacx.2025.100715","DOIUrl":"10.1016/j.jvacx.2025.100715","url":null,"abstract":"<div><h3>Introduction</h3><div>The resurgence of vaccine-preventable diseases poses a significant global public health challenge, exacerbated by the rise of anti-vaccination attitudes. The aim of this study was to validate the Slovak version of the Vaccination Attitudes Examination (VAX) questionnaire and to examine the attitudes towards vaccination in Slovakia.</div></div><div><h3>Methods</h3><div>The VAX scale questionnaire, translated into Slovak and validated, was used for the survey. The VAX scale uses 12 statements assessing anti-vaccination attitudes. Each statement is scored on a 6-point Likert scale, with higher total score indicates more negative attitudes towards vaccinations. Our questionnaire also included demographic questions (age, gender, residence, education level, profession, and economic activity). For validation, the questionnaire was translated into the Slovak using forward and backward translations. The validation survey was conducted on the sample size of 115 participants. Correlation was calculated using Pearson's correlation coefficient, internal consistency was tested. Confirmatory factor analysis (CFA) was performed to assess validity. Subsequently, a pilot study was conducted in March 2023 with a sample size of 473 participants.</div></div><div><h3>Results</h3><div>The VAX scale demonstrated strong internal consistency (Cronbach's alpha = 0.925) and reliability. The results of the CFA were comparable to findings from other languages versions. The pilot study revealed that parents, non-healthcare professionals, and older individuals exhibited higher anti-vaccination attitudes. In contrast, healthcare professionals had the lowest VAX scores, reflecting more pro-vaccination attitudes.</div></div><div><h3>Conclusion</h3><div>These findings highlight the need for targeted educational and communication strategies to address vaccine hesitancy. By identifying demographic patterns and potential hotspots of vaccine skepticism, public health initiatives can be better tailored to improve vaccination rates. The validated Slovak VAX scale provides a reliable tool for ongoing assessment and intervention efforts.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"26 ","pages":"Article 100715"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144911872","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}
This article presents a cross-country analysis of qualitative research reports on the barriers and drivers of HPV vaccination-related behavior among parents and health workers in seven middle-income countries using the COM-B theoretical framework. Four reports are from countries that had already introduced the HPV vaccine — Georgia, Moldova, Turkmenistan, and Uzbekistan, while the other three reports are from Kazakhstan, Kosovo, and Tajikistan which were preparing for HPV vaccine introduction in 2023 and 2024.
Results
The cross-country analysis revealed that health workers (HWs), especially specialists like gynecologists and oncologists, were viewed as trusted sources of vaccination information by both parents and HWs. However, HWs faced gaps in HPV vaccine knowledge and communication skills, and these gaps persisted in some form even after training was conducted in countries that had already introduced the HPV vaccine. In addition, these specialists were not always included when training sessions were conducted with family doctors and nurses in preparation for the vaccine's introduction. Parents also experience knowledge gaps, safety concerns, and lack of trust. Parents across countries shared concerns related to HPV vaccine safety and effectiveness and were often exposed to misconceptions or misinformation through media and social networks. This was compounded by the lack of a strong and confident recommendation from HWs and poor patient-provider communication.
Conclusions
The analyzed reports highlighted the need for tailored, multi-faceted interventions that account for locally specific issues, influencers, and target groups. Two prominent recommendations posited in the reports were: 1) engaging parents and addressing their concerns at the community level, and 2) ensuring HPV vaccine confidence through HW training and engagement, especially for specialists, and providing access to evidence-based information for HWs and others who influence vaccine acceptance.
{"title":"Cross-country analysis on HPV vaccination behaviors among health workers and parents: a qualitative report from seven middle-income countries","authors":"Gulaiim Almatkyzy , Sahil Khan Warsi , Siff Malue Nielsen , Brett J. Craig","doi":"10.1016/j.jvacx.2025.100725","DOIUrl":"10.1016/j.jvacx.2025.100725","url":null,"abstract":"<div><h3>Purpose</h3><div>This article presents a cross-country analysis of qualitative research reports on the barriers and drivers of HPV vaccination-related behavior among parents and health workers in seven middle-income countries using the COM-B theoretical framework. Four reports are from countries that had already introduced the HPV vaccine — Georgia, Moldova, Turkmenistan, and Uzbekistan, while the other three reports are from Kazakhstan, Kosovo, and Tajikistan which were preparing for HPV vaccine introduction in 2023 and 2024.</div></div><div><h3>Results</h3><div>The cross-country analysis revealed that health workers (HWs), especially specialists like gynecologists and oncologists, were viewed as trusted sources of vaccination information by both parents and HWs. However, HWs faced gaps in HPV vaccine knowledge and communication skills, and these gaps persisted in some form even after training was conducted in countries that had already introduced the HPV vaccine. In addition, these specialists were not always included when training sessions were conducted with family doctors and nurses in preparation for the vaccine's introduction. Parents also experience knowledge gaps, safety concerns, and lack of trust. Parents across countries shared concerns related to HPV vaccine safety and effectiveness and were often exposed to misconceptions or misinformation through media and social networks. This was compounded by the lack of a strong and confident recommendation from HWs and poor patient-provider communication.</div></div><div><h3>Conclusions</h3><div>The analyzed reports highlighted the need for tailored, multi-faceted interventions that account for locally specific issues, influencers, and target groups. Two prominent recommendations posited in the reports were: 1) engaging parents and addressing their concerns at the community level, and 2) ensuring HPV vaccine confidence through HW training and engagement, especially for specialists, and providing access to evidence-based information for HWs and others who influence vaccine acceptance.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100725"},"PeriodicalIF":2.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107531","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 : 2025-09-16DOI: 10.1016/j.jvacx.2025.100724
María Eugenia Cecchini , Sofía Arsaute , Ivana Dalila Montironi , Dardo Andrés Roma , José Raviolo , Federico Ruiz Moreno , Belkys Maletto , Nahuel Matías Camacho , Fernando Javier Mañas , Romina Valeria Bellingeri , Laura Noelia Cariddi
Enterotoxigenic Escherichia coli (ETEC) is the leading cause of post-weaning diarrhea in piglets. The development of novel adjuvanted vaccines that can be administered directly to piglets remains a priority for the swine industry. Minthostachys verticillata essential oil (EO) has shown adjuvant effects, but its poor stability and solubility limit its use, that could be solved by emulsification. This study aimed to evaluate the effect of an EO-based nanoadjuvant to enhance the immunogenicity of ETEC in an experimental vaccine using mice as a preliminary model. A nanoemulsion (NEO) was formulated with EO (20 % v/v), Tween 80 (0.75 % v/v), and Span 60 (0.25 % w/v) using a high-energy method. The interaction between NEO and ETEC was analyzed by a scanning electron microscope. Experimental vaccines were prepared with inactivated ETEC strain combined with NEO (0.5, 0.75, and 1 mg/mL of EO) or EO (1 mg/mL) as adjuvants. Controls included Incomplete Freund's Adjuvant (IFA), Tween 80/Span 60 as a vehicle control, saline, and non-adjuvanted formulations. Balb/c mice were subcutaneously injected with the experimental vaccines, with four doses administered every 14 days. Antigen-specific antibody titers (IgG, IgG1, IgG2a), opsonizing capacity, and CD4+/CD69+ and CD8+/CD69+ T cells activation were evaluated. Splenic mononuclear cell proliferation and cytokine production (IFN-γ and IL-10) were also measured. Hepatic enzyme levels and malondialdehyde (MDA) concentrations were assessed to evaluate toxicity. NEO induced anti-ETEC IgG with significant opsonizing potential, increase in the percentage of CD4+/CD69+ and CD8+/CD69+ T cells, and production of IFN-γ. It caused no local reactogenicity, did not alter hepatic enzyme levels, and did not increase MDA concentrations. In conclusion, NEO demonstrated adjuvant potential, activating both humoral and cellular immune responses against ETEC without evidence of toxicity.
{"title":"A natural oil-based nanoadjuvant enhances the immunogenicity of enterotoxigenic Escherichia coli (ETEC) in an experimental vaccine","authors":"María Eugenia Cecchini , Sofía Arsaute , Ivana Dalila Montironi , Dardo Andrés Roma , José Raviolo , Federico Ruiz Moreno , Belkys Maletto , Nahuel Matías Camacho , Fernando Javier Mañas , Romina Valeria Bellingeri , Laura Noelia Cariddi","doi":"10.1016/j.jvacx.2025.100724","DOIUrl":"10.1016/j.jvacx.2025.100724","url":null,"abstract":"<div><div>Enterotoxigenic <em>Escherichia coli</em> (ETEC) is the leading cause of post-weaning diarrhea in piglets. The development of novel adjuvanted vaccines that can be administered directly to piglets remains a priority for the swine industry. <em>Minthostachys verticillata</em> essential oil (EO) has shown adjuvant effects, but its poor stability and solubility limit its use, that could be solved by emulsification. This study aimed to evaluate the effect of an EO-based nanoadjuvant to enhance the immunogenicity of ETEC in an experimental vaccine using mice as a preliminary model. A nanoemulsion (NEO) was formulated with EO (20 % v/v), Tween 80 (0.75 % v/v), and Span 60 (0.25 % w/v) using a high-energy method. The interaction between NEO and ETEC was analyzed by a scanning electron microscope. Experimental vaccines were prepared with inactivated ETEC strain combined with NEO (0.5, 0.75, and 1 mg/mL of EO) or EO (1 mg/mL) as adjuvants. Controls included Incomplete Freund's Adjuvant (IFA), Tween 80/Span 60 as a vehicle control, saline, and non-adjuvanted formulations. Balb/c mice were subcutaneously injected with the experimental vaccines, with four doses administered every 14 days. Antigen-specific antibody titers (IgG, IgG1, IgG2a), opsonizing capacity, and CD4<sup>+</sup>/CD69<sup>+</sup> and CD8<sup>+</sup>/CD69<sup>+</sup> T cells activation were evaluated. Splenic mononuclear cell proliferation and cytokine production (IFN-γ and IL-10) were also measured. Hepatic enzyme levels and malondialdehyde (MDA) concentrations were assessed to evaluate toxicity. NEO induced anti-ETEC IgG with significant opsonizing potential, increase in the percentage of CD4<sup>+</sup>/CD69<sup>+</sup> and CD8<sup>+</sup>/CD69<sup>+</sup> T cells, and production of IFN-γ. It caused no local reactogenicity, did not alter hepatic enzyme levels, and did not increase MDA concentrations. In conclusion, NEO demonstrated adjuvant potential, activating both humoral and cellular immune responses against ETEC without evidence of toxicity.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100724"},"PeriodicalIF":2.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107623","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 : 2025-09-15DOI: 10.1016/j.jvacx.2025.100720
Heidi Sze Lok Fan , Edmond Pui Hang Choi , Elizabeth Keys , Rishma Chooniedass , Stephanie Masina , Alex Halonen , Kalysse Mantai , Marie Tarrant
Introduction
The Vaccine Hesitancy Scale (VHS) was developed by the World Health Organization's Strategic Advisory Group of Experts on Immunization (SAGE) to examine parents' vaccine hesitancy toward childhood vaccines. The VHS has been validated and modified to assess vaccine hesitancy toward specific vaccines, including influenza and human papillomavirus vaccines, but not the COVID-19 vaccine. The objective of this study is to validate a modified VHS for the COVID-19 vaccine among pregnant and breastfeeding persons, and parents of children under 12 years of age.
Methods
A cross-sectional survey was conducted in British Columbia, Canada from October to December 2021. A total of 1510 participants including pregnant and breastfeeding persons, and parents of children <12 years of age were included in the analysis. Participants completed questionnaires tailored to their respective groups based on self-identification. Confirmatory factor analysis was conducted to assess the original VHS structure. The data were then randomly split into training and validation sets for exploratory and confirmatory factor analyses. Factor structure, internal construct validity, internal consistency, and known-group validity were evaluated.
Results
The original VHS model showed a poor fit. Exploratory factor analysis identified a revised one-factor model (VHS-COVID19), which showed satisfactory fit in the validation sample for pregnant participants (comparative fit index [CFI] = 0.999; root mean square error of approximation [RMSEA] = 0.041; standardized root mean squared residual [SRMR] = 0.008; Tucker-Lewis Index [TLI] = 0.997), breastfeeding participants (CFI = 0.995; RMAEA = 0.089; SRMR = 0.006; TLI = 0.990) and parent participants (CFI = 0.995; RMAEA = 0.080; SRMR = 0.004; TLI = 0.992). The revised scale comprised five items for pregnant and breastfeeding participants and six for parent participants. VHS-COVID19 showed high internal construct validity and reliability.
Conclusions
The VHS-COVID19 shows adequate psychometric performance for assessing COVID-19 vaccine hesitancy among pregnant, breastfeeding persons, and parents. It is easy to administer and can be used by healthcare providers to rapidly assess vaccine hesitancy of the targeted population in clinical settings.
{"title":"COVID-19 Vaccine Hesitancy Scale: Psychometric properties and validation among pregnant and breastfeeding persons and parents","authors":"Heidi Sze Lok Fan , Edmond Pui Hang Choi , Elizabeth Keys , Rishma Chooniedass , Stephanie Masina , Alex Halonen , Kalysse Mantai , Marie Tarrant","doi":"10.1016/j.jvacx.2025.100720","DOIUrl":"10.1016/j.jvacx.2025.100720","url":null,"abstract":"<div><h3>Introduction</h3><div>The Vaccine Hesitancy Scale (VHS) was developed by the World Health Organization's Strategic Advisory Group of Experts on Immunization (SAGE) to examine parents' vaccine hesitancy toward childhood vaccines. The VHS has been validated and modified to assess vaccine hesitancy toward specific vaccines, including influenza and human papillomavirus vaccines, but not the COVID-19 vaccine. The objective of this study is to validate a modified VHS for the COVID-19 vaccine among pregnant and breastfeeding persons, and parents of children under 12 years of age.</div></div><div><h3>Methods</h3><div>A cross-sectional survey was conducted in British Columbia, Canada from October to December 2021. A total of 1510 participants including pregnant and breastfeeding persons, and parents of children <12 years of age were included in the analysis. Participants completed questionnaires tailored to their respective groups based on self-identification. Confirmatory factor analysis was conducted to assess the original VHS structure. The data were then randomly split into training and validation sets for exploratory and confirmatory factor analyses. Factor structure, internal construct validity, internal consistency, and known-group validity were evaluated.</div></div><div><h3>Results</h3><div>The original VHS model showed a poor fit. Exploratory factor analysis identified a revised one-factor model (VHS-COVID19), which showed satisfactory fit in the validation sample for pregnant participants (comparative fit index [CFI] = 0.999; root mean square error of approximation [RMSEA] = 0.041; standardized root mean squared residual [SRMR] = 0.008; Tucker-Lewis Index [TLI] = 0.997), breastfeeding participants (CFI = 0.995; RMAEA = 0.089; SRMR = 0.006; TLI = 0.990) and parent participants (CFI = 0.995; RMAEA = 0.080; SRMR = 0.004; TLI = 0.992). The revised scale comprised five items for pregnant and breastfeeding participants and six for parent participants<em>.</em> VHS-COVID19 showed high internal construct validity and reliability.</div></div><div><h3>Conclusions</h3><div>The VHS-COVID19 shows adequate psychometric performance for assessing COVID-19 vaccine hesitancy among pregnant, breastfeeding persons, and parents. It is easy to administer and can be used by healthcare providers to rapidly assess vaccine hesitancy of the targeted population in clinical settings.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100720"},"PeriodicalIF":2.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107626","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}
Cervical cancer is one of the most prevalent cancers affecting women especially in low- and middle income countries and is caused by persistent infection with human papillomavirus (HPV). HPV vaccination can significantly reduce the cervical cancer burden. However, HPV vaccination is not yet included in the Tunisian immunization program. To inform decision-making on HPV vaccine introduction in Tunisia, we conducted a comparative modeling study to project the health impact and cost-effectiveness of four HPV vaccines (Cecolin, Cervarix, Gardasil, 4, and Gardasil-9) targeted to 12-year-old girls in 2025.
Methods:
We used two static cohort models (UNIVAC and Papillomavirus Rapid Interface for Modeling and Economics (PRIME)) to estimate the health and economic impact of HPV vaccination from the health system and societal perspectives. Our data inputs to the model include demography and cervical cancer burden as well as unit costs for treatment, vaccines, and vaccine delivery. We estimated health impact in terms of cases, deaths, and disability-adjusted life years (DALYs) averted by HPV vaccination, and economic impact in terms of vaccination costs, treatment costs saved, net cost, and incremental cost-effectiveness ratios (ICERs).
Results:
We estimated that Cecolin is the most cost-effective HPV vaccine in Tunisia, particularly when cross-protection is considered. Despite Cervarix offering greater health benefits of 70% versus 62% reductions in cervical cancer cases and deaths at 87% coverage, Cecolin has lower net costs and is more favorable across different willingness-to-pay (WTP) thresholds. At a WTP of USD 1169 per DALY averted (30% of Tunisia’s GDP per capita), Cecolin and Cervarix demonstrate similar probabilities of being cost-effective.
Conclusion:
Based on the vaccine impact estimates generated by the UNIVAC and PRIME models, we inferred that the four HPV vaccines (Cecolin, Cervarix Gardasil,4, and Gardasil-9) were cost-effective in the Tunisian context. This evidence is useful to inform HPV vaccine introduction in Tunisia.
{"title":"Potential health impact and cost-effectiveness of human papillomavirus vaccination in Tunisia: A comparative modeling study","authors":"Oumaima Laraj , Beya Benzina , Ahlem Gzara , Amira Kebir , Kaja Abbas , Slimane BenMiled","doi":"10.1016/j.jvacx.2025.100712","DOIUrl":"10.1016/j.jvacx.2025.100712","url":null,"abstract":"<div><h3>Background:</h3><div>Cervical cancer is one of the most prevalent cancers affecting women especially in low- and middle income countries and is caused by persistent infection with human papillomavirus (HPV). HPV vaccination can significantly reduce the cervical cancer burden. However, HPV vaccination is not yet included in the Tunisian immunization program. To inform decision-making on HPV vaccine introduction in Tunisia, we conducted a comparative modeling study to project the health impact and cost-effectiveness of four HPV vaccines (Cecolin, Cervarix, Gardasil, 4, and Gardasil-9) targeted to 12-year-old girls in 2025.</div></div><div><h3>Methods:</h3><div>We used two static cohort models (UNIVAC and Papillomavirus Rapid Interface for Modeling and Economics (PRIME)) to estimate the health and economic impact of HPV vaccination from the health system and societal perspectives. Our data inputs to the model include demography and cervical cancer burden as well as unit costs for treatment, vaccines, and vaccine delivery. We estimated health impact in terms of cases, deaths, and disability-adjusted life years (DALYs) averted by HPV vaccination, and economic impact in terms of vaccination costs, treatment costs saved, net cost, and incremental cost-effectiveness ratios (ICERs).</div></div><div><h3>Results:</h3><div>We estimated that Cecolin is the most cost-effective HPV vaccine in Tunisia, particularly when cross-protection is considered. Despite Cervarix offering greater health benefits of 70% versus 62% reductions in cervical cancer cases and deaths at 87% coverage, Cecolin has lower net costs and is more favorable across different willingness-to-pay (WTP) thresholds. At a WTP of USD 1169 per DALY averted (30% of Tunisia’s GDP per capita), Cecolin and Cervarix demonstrate similar probabilities of being cost-effective.</div></div><div><h3>Conclusion:</h3><div>Based on the vaccine impact estimates generated by the UNIVAC and PRIME models, we inferred that the four HPV vaccines (Cecolin, Cervarix Gardasil,4, and Gardasil-9) were cost-effective in the Tunisian context. This evidence is useful to inform HPV vaccine introduction in Tunisia.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100712"},"PeriodicalIF":2.2,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050302","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 : 2025-09-08DOI: 10.1016/j.jvacx.2025.100718
Lin Yao , Xiao-Lin Jiang , Jun-Xia Cao , Qiang Guo , Meng-Na Wu , Shu-Zhi Wu , Li-Jun Duan , Yuan Shen , Bing-Dong Zhan , Jun-Fen Lin , Ming-Dong Jiang , Hong-Hong Peng , Yu-Wei Zhang , Guo-Jian Yang , Xue-Dong Song , Chao Shi , Ji-Yan Zhang , Wen-Guo Jiang , Mai-Juan Ma
Determining the durability of immunity after SARS-CoV-2 infection or vaccination is critical for understanding immune protection upon reinfection and optimizing vaccine design. We measured SARS-CoV-2-specific antibodies and T-cell responses in COVID-19 convalescent patients up to 14 months after infection and COVID-19 convalescents who received two doses of BBIBP-CorV at 6-month intervals. We observed that most convalescents had durable neutralizing antibody and T-cell responses against the SARS-CoV-2 Wuhan strain at least 14 months after infection. Administering a booster dose to convalescent patients significantly increased neutralizing antibodies against the Wuhan strain, but neutralization activity against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/BA.5 was significantly decreased. Six months after the first dose vaccination, the neutralizing antibody levels significantly declined and were not further enhanced by a second dose. Omicron BA.1-specific T-cell responses were detectable in most convalescent patients and were not significantly affected by vaccination. These analyses provide insights into the durability of the immune response after infection and hybrid immunization and may be relevant for future vaccine strategies.
确定SARS-CoV-2感染或疫苗接种后免疫的持久性对于了解再感染后的免疫保护和优化疫苗设计至关重要。我们测量了感染后14个月的COVID-19恢复期患者和每隔6个月接受两剂BBIBP-CorV的COVID-19恢复期患者的sars - cov -2特异性抗体和t细胞反应。我们观察到，大多数康复者在感染后至少14个月对SARS-CoV-2武汉株有持久的中和抗体和t细胞反应。恢复期患者给予加强剂量后，抗武汉株的中和抗体显著增加，但抗欧米克隆ba1 .1、ba2 .2、ba2.12.1和ba4 /BA的中和活性明显增加。5显著降低。第一剂疫苗接种后6个月，中和抗体水平显著下降，第二剂疫苗接种后未进一步增强。在大多数恢复期患者中可检测到Omicron ba .1特异性t细胞反应，并且接种疫苗不显著影响。这些分析为感染和混合免疫后免疫反应的持久性提供了见解，并可能与未来的疫苗策略相关。
{"title":"Durability of neutralizing antibody and T-cell responses in COVID-19 patients after infection and booster vaccination","authors":"Lin Yao , Xiao-Lin Jiang , Jun-Xia Cao , Qiang Guo , Meng-Na Wu , Shu-Zhi Wu , Li-Jun Duan , Yuan Shen , Bing-Dong Zhan , Jun-Fen Lin , Ming-Dong Jiang , Hong-Hong Peng , Yu-Wei Zhang , Guo-Jian Yang , Xue-Dong Song , Chao Shi , Ji-Yan Zhang , Wen-Guo Jiang , Mai-Juan Ma","doi":"10.1016/j.jvacx.2025.100718","DOIUrl":"10.1016/j.jvacx.2025.100718","url":null,"abstract":"<div><div>Determining the durability of immunity after SARS-CoV-2 infection or vaccination is critical for understanding immune protection upon reinfection and optimizing vaccine design. We measured SARS-CoV-2-specific antibodies and T-cell responses in COVID-19 convalescent patients up to 14 months after infection and COVID-19 convalescents who received two doses of BBIBP-CorV at 6-month intervals. We observed that most convalescents had durable neutralizing antibody and T-cell responses against the SARS-CoV-2 Wuhan strain at least 14 months after infection. Administering a booster dose to convalescent patients significantly increased neutralizing antibodies against the Wuhan strain, but neutralization activity against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/BA.5 was significantly decreased. Six months after the first dose vaccination, the neutralizing antibody levels significantly declined and were not further enhanced by a second dose. Omicron BA.1-specific T-cell responses were detectable in most convalescent patients and were not significantly affected by vaccination. These analyses provide insights into the durability of the immune response after infection and hybrid immunization and may be relevant for future vaccine strategies.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100718"},"PeriodicalIF":2.2,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107624","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 : 2025-09-08DOI: 10.1016/j.jvacx.2025.100719
Grazia Alessio , Drieda Zaçe , Christopher Jones , Andrea Di Lorenzo , Alessandra Imeneo , Vincenzo Malagnino , Elisabetta Teti , Loredana Sarmati , Alessandra Ruggiero , Marco Iannetta , Anna Maria Geretti , EVAN-CoV-Study Group
Introduction
Vaccination against COVID-19 and influenza is recommended for people living with HIV, but real-world uptake data remain incomplete, especially in populations facing socioeconomic barriers. We assessed uptake and associated factors at an HIV outpatient centre serving a socioeconomically disadvantaged area of Rome. Participants were in stable HIV care and were encouraged to receive vaccination at no cost, at a location of choice. COVID-19 vaccination was initially available both on-site and externally; influenza vaccination was only available externally.
Methods
We analysed a random 50 % sample of 750 adults, retrieving data from the vaccination registry and medical records. Full COVID-19 vaccination was defined as primary vaccination plus 1 additional dose. Logistic regression identified factors associated with uptake.
Results
Between December 2020 and July 2024, 331/375 (88.3 %) participants received primary COVID-19 vaccination (typically two mRNA vaccine doses 3–4 weeks apart) and 286/375 (76.3 %) received ≥1 additional dose, with most vaccinations occurring before September 2023. Odds of full vaccination were lower among participants <50 years and heterosexual men and women (vs. men who have sex with men). Other associated factors included migrant background, injecting drug use, history of advanced immunosuppression, HIV viraemia, and CD4 <500 cells/mm3. Influenza vaccination uptake (2022/2023) was low (99/375, 26.4 %), although almost 4-fold higher among those vaccinated against COVID-19.
Conclusions
Disparities in COVID-19 vaccine coverage and suboptimal influenza vaccination uptake persist among adults stably engaged in HIV care. Addressing barriers, particularly in those with additional vulnerabilities, and integrating vaccination into HIV services may improve uptake and reduce preventable illness.
{"title":"COVID-19 and influenza vaccination among adults stably engaged in HIV care","authors":"Grazia Alessio , Drieda Zaçe , Christopher Jones , Andrea Di Lorenzo , Alessandra Imeneo , Vincenzo Malagnino , Elisabetta Teti , Loredana Sarmati , Alessandra Ruggiero , Marco Iannetta , Anna Maria Geretti , EVAN-CoV-Study Group","doi":"10.1016/j.jvacx.2025.100719","DOIUrl":"10.1016/j.jvacx.2025.100719","url":null,"abstract":"<div><h3>Introduction</h3><div>Vaccination against COVID-19 and influenza is recommended for people living with HIV, but real-world uptake data remain incomplete, especially in populations facing socioeconomic barriers. We assessed uptake and associated factors at an HIV outpatient centre serving a socioeconomically disadvantaged area of Rome. Participants were in stable HIV care and were encouraged to receive vaccination at no cost, at a location of choice. COVID-19 vaccination was initially available both on-site and externally; influenza vaccination was only available externally.</div></div><div><h3>Methods</h3><div>We analysed a random 50 % sample of 750 adults, retrieving data from the vaccination registry and medical records. Full COVID-19 vaccination was defined as primary vaccination plus <span><math><mo>≥</mo></math></span>1 additional dose. Logistic regression identified factors associated with uptake.</div></div><div><h3>Results</h3><div>Between December 2020 and July 2024, 331/375 (88.3 %) participants received primary COVID-19 vaccination (typically two mRNA vaccine doses 3–4 weeks apart) and 286/375 (76.3 %) received ≥1 additional dose, with most vaccinations occurring before September 2023. Odds of full vaccination were lower among participants <50 years and heterosexual men and women (vs. men who have sex with men). Other associated factors included migrant background, injecting drug use, history of advanced immunosuppression, HIV viraemia, and CD4 <500 cells/mm<sup>3</sup>. Influenza vaccination uptake (2022/2023) was low (99/375, 26.4 %), although almost 4-fold higher among those vaccinated against COVID-19.</div></div><div><h3>Conclusions</h3><div>Disparities in COVID-19 vaccine coverage and suboptimal influenza vaccination uptake persist among adults stably engaged in HIV care. Addressing barriers, particularly in those with additional vulnerabilities, and integrating vaccination into HIV services may improve uptake and reduce preventable illness.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"27 ","pages":"Article 100719"},"PeriodicalIF":2.2,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050301","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 : 2025-08-07DOI: 10.1016/j.jvacx.2025.100700
Sinead E. Morris , Sarabeth M. Mathis , Jessie R. Chung , Brendan Flannery , Alissa O'Halloran , Charisse N. Cummings , Shikha Garg , Peng-Jun Lu , Tammy A. Santibanez , Carrie Reed , Matthew Biggerstaff , A. Danielle Iuliano
Seasonal influenza causes substantial morbidity and mortality in the United States. The U.S. Centers for Disease Control and Prevention (CDC) uses a compartmental framework to estimate the annual disease burden and burden prevented by vaccination for all influenza types and subtypes combined. However, these estimates do not capture underlying shifts in disease burden caused by different circulating influenza virus types or subtypes. We demonstrate an extension of the current framework to estimate disease burden and burden prevented by vaccination for influenza A virus subtypes A(H1N1) and A(H3N2), and influenza type B viruses. We applied this method to data from the 2016/17 to 2019/20 seasons that included age- and virus-specific hospitalizations and vaccine effectiveness estimates, and age-specific vaccination coverage estimates. We estimated the number of symptomatic illnesses, medically-attended illnesses, hospitalizations, and deaths caused by each virus, and the corresponding number prevented by vaccination. Disease burden and vaccine-prevented disease burden varied substantially by season, age, and virus type or subtype. The greatest disease burden was estimated in 2017/18, whereas 2019/20 had the greatest burden prevented by vaccination. Influenza A viruses contributed most to disease burden in all seasons. Vaccination against influenza B viruses prevented the largest percentage of hospitalizations among children and adults <65 years, whereas vaccination against A(H1N1) prevented the largest percentage of hospitalizations among adults ≥65 years. Overall, our results highlight complex variability in influenza disease burden by season, age, and virus type and subtype. These findings can be used to improve our understanding of the factors impacting influenza disease burden each season and to enhance communications of the value of influenza vaccination.
{"title":"Estimating historical disease burden and the impact of vaccination by influenza type and subtype in the United States, 2016–2020","authors":"Sinead E. Morris , Sarabeth M. Mathis , Jessie R. Chung , Brendan Flannery , Alissa O'Halloran , Charisse N. Cummings , Shikha Garg , Peng-Jun Lu , Tammy A. Santibanez , Carrie Reed , Matthew Biggerstaff , A. Danielle Iuliano","doi":"10.1016/j.jvacx.2025.100700","DOIUrl":"10.1016/j.jvacx.2025.100700","url":null,"abstract":"<div><div>Seasonal influenza causes substantial morbidity and mortality in the United States. The U.S. Centers for Disease Control and Prevention (CDC) uses a compartmental framework to estimate the annual disease burden and burden prevented by vaccination for all influenza types and subtypes combined. However, these estimates do not capture underlying shifts in disease burden caused by different circulating influenza virus types or subtypes. We demonstrate an extension of the current framework to estimate disease burden and burden prevented by vaccination for influenza A virus subtypes A(H1N1) and A(H3N2), and influenza type B viruses. We applied this method to data from the 2016/17 to 2019/20 seasons that included age- and virus-specific hospitalizations and vaccine effectiveness estimates, and age-specific vaccination coverage estimates. We estimated the number of symptomatic illnesses, medically-attended illnesses, hospitalizations, and deaths caused by each virus, and the corresponding number prevented by vaccination. Disease burden and vaccine-prevented disease burden varied substantially by season, age, and virus type or subtype. The greatest disease burden was estimated in 2017/18, whereas 2019/20 had the greatest burden prevented by vaccination. Influenza A viruses contributed most to disease burden in all seasons. Vaccination against influenza B viruses prevented the largest percentage of hospitalizations among children and adults <65 years, whereas vaccination against A(H1N1) prevented the largest percentage of hospitalizations among adults ≥65 years. Overall, our results highlight complex variability in influenza disease burden by season, age, and virus type and subtype. These findings can be used to improve our understanding of the factors impacting influenza disease burden each season and to enhance communications of the value of influenza vaccination.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"26 ","pages":"Article 100700"},"PeriodicalIF":2.2,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829839","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}
We have previously reported reasons for vaccine hesitance among those who did not receive the coronavirus disease 2019 (COVID-19) vaccination. However, the detailed causes of hesitancy related to booster vaccinations remain largely uninvestigated. This study aimed to describe why individuals who received one or two vaccine doses avoided booster shots.
Methods
In March 2023, a cross-sectional Internet survey was conducted to investigate the reasons for vaccine hesitancy and the extent of adverse reactions following vaccination among individuals who had not received a booster dose in Japan. Survey items included social demographics, comorbidities, history of SARS-CoV-2 infection, history of COVID-19 vaccination, adverse reactions to COVID-19 vaccines, and reasons for vaccination decline. The reasons for avoiding vaccination were summarized.
Results
In this study, 545 individuals were included: 262 did not receive vaccination, 21 received one dose, and 263 received two doses by March 2023. The most common reason for avoiding subsequent booster doses among individuals who received one or two doses of the vaccine was concerns about adverse reactions (n[%] = 192 [67.8 %]), followed by concerns about vaccine safety (n[%] = 154 [54.4 %]). The proportion of vaccine safety concerns was lower in the booster vaccination hesitant group than in the non-vaccination group (p < 0.001). The group that avoided booster vaccination due to adverse reactions experienced all types of adverse reactions more severely than those for which adverse reactions were not a reason for vaccine hesitancy.
Conclusions
The most prominent reason for avoiding booster doses after receiving one or two doses of the COVID-19 vaccine was related to concerns regarding associated side effects. To prevent vaccine hesitancy regarding booster doses, including COVID-19, the strategy for reducing discomfort caused by these adverse reactions should involve the first and second doses.
{"title":"Reasons for unvaccinated booster dose of COVID-19, adverse reaction after vaccination, and COVID-19 infection status among those with COVID-19 booster vaccination hesitancy","authors":"Sho Takahashi , Shohei Sakai , Yuichiro Ohki , Kaede Tobe , Yurie Kobashi , Masaharu Tsubokura","doi":"10.1016/j.jvacx.2025.100701","DOIUrl":"10.1016/j.jvacx.2025.100701","url":null,"abstract":"<div><h3>Background</h3><div>We have previously reported reasons for vaccine hesitance among those who did not receive the coronavirus disease 2019 (COVID-19) vaccination. However, the detailed causes of hesitancy related to booster vaccinations remain largely uninvestigated. This study aimed to describe why individuals who received one or two vaccine doses avoided booster shots.</div></div><div><h3>Methods</h3><div>In March 2023, a cross-sectional Internet survey was conducted to investigate the reasons for vaccine hesitancy and the extent of adverse reactions following vaccination among individuals who had not received a booster dose in Japan. Survey items included social demographics, comorbidities, history of SARS-CoV-2 infection, history of COVID-19 vaccination, adverse reactions to COVID-19 vaccines, and reasons for vaccination decline. The reasons for avoiding vaccination were summarized.</div></div><div><h3>Results</h3><div>In this study, 545 individuals were included: 262 did not receive vaccination, 21 received one dose, and 263 received two doses by March 2023. The most common reason for avoiding subsequent booster doses among individuals who received one or two doses of the vaccine was concerns about adverse reactions (n[%] = 192 [67.8 %]), followed by concerns about vaccine safety (n[%] = 154 [54.4 %]). The proportion of vaccine safety concerns was lower in the booster vaccination hesitant group than in the non-vaccination group (<em>p</em> < 0.001). The group that avoided booster vaccination due to adverse reactions experienced all types of adverse reactions more severely than those for which adverse reactions were not a reason for vaccine hesitancy.</div></div><div><h3>Conclusions</h3><div>The most prominent reason for avoiding booster doses after receiving one or two doses of the COVID-19 vaccine was related to concerns regarding associated side effects. To prevent vaccine hesitancy regarding booster doses, including COVID-19, the strategy for reducing discomfort caused by these adverse reactions should involve the first and second doses.</div></div>","PeriodicalId":43021,"journal":{"name":"Vaccine: X","volume":"26 ","pages":"Article 100701"},"PeriodicalIF":2.2,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841615","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}
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