Effectiveness of the TYPHIBEV® (Vi-CRM197 conjugate) vaccine introduction in Nepal: a test-negative, case-control study
Rattachement africain : np, us, ca, th. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
ABSTRACT Introduction Typhoid fever, caused by Salmonella Typhi, remains a major cause of global morbidity and mortality. TYPHIBEV®, a Vi-CRM197 typhoid conjugate vaccine (TCV), received WHO prequalification based on immunogenicity data, but there have been no published data on clinical efficacy or effectiveness. We aimed to evaluate the effectiveness of TYPHIBEV®, which was introduced through a catch-up campaign and routine immunization in Nepal, in preventing blood culture-confirmed typhoid fever among children. Methods We conducted a test-negative, case-control study where typhoid test-positive cases were defined as vaccine-eligible pediatric patients who tested positive for Salmonella Typhi by blood culture at participating health facilities and test-negative controls were vaccine-eligible patients who tested negative for S . Typhi on blood cultures. We matched by age, location, date of blood culture, and surveillance site. We used conditional logistic regression to calculate odds ratios (OR), and vaccine effectiveness was calculated as 1-OR. Results Between October 1, 2022 and December 31, 2024, 40 typhoid cases and 113 matched, test-negative controls were enrolled. Both cases and controls were similar in sociodemographic characteristics and water, sanitation and hygiene-related living conditions. Among 39 cases and 108 controls with known vaccine status, 20 cases (51%) and 91 controls (84%) had received TCV. Vaccine effectiveness was 89% (95% CI: 65-97%) and was lower among children <5 years (72%, 95% CI: -203-97%) compared with those 5-15 years (98%, 95% CI: 80-100%). Vaccine effectiveness estimates did not significantly differ when restricted to participants with documented vaccination status. Conclusion The findings indicate that TYPHIBEV® was highly effective in preventing typhoid fever up to 30 months following a national introduction, with effectiveness estimates comparable to those observed for Typbar-TCV®.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Effectiveness of the TYPHIBEV® (Vi-CRM197 conjugate) vaccine introduction in Nepal: a test-negative, case-control study
- Date Crossref
- 20/11/2025
- Éditeur
- openRxiv
- Type
- posted-content
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Dhulikhel Hospital pays non établi dans la noticeÉtablissement de santé
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Kathmandu University . Department of Microbiology pays non établi dans la noticeUniversité ou école supérieure
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Stanford University pays non établi dans la noticeUniversité ou école supérieure
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Kathmandu Medical College Teaching Hospital pays non établi dans la noticeInstitution
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Bir Hospital pays non établi dans la noticeÉtablissement de santé
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Hanby Environmental (United States) pays non établi dans la noticeEntreprise
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Kanti Children's Hospital pays non établi dans la noticeÉtablissement de santé
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Civil Service Hospital pays non établi dans la noticeÉtablissement de santé
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Sabin Vaccine Institute pays non établi dans la noticeOrganisation à but non lucratif
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Toronto General Hospital pays non établi dans la noticeÉtablissement de santé
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Mahidol Oxford Tropical Medicine Research Unit pays non établi dans la noticeStructure de recherche
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Kathmandu Model Hospital pays non établi dans la noticeÉtablissement de santé
Dhulikhel Hospital, . Department of Microbiology — Kathmandu University et Stanford University, avec 9 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.