Seven-year follow-up of the immune response after one or 2 doses of inactivated hepatitis A vaccine given at 1 year of age in the Mendoza Province of Argentina. Issue 11 (2nd November 2017)

• Record Type: Journal Article
• Authors: Espul, Carlos; Benedetti, Laura; Linares, Mariela; Cuello, Hector; Lo Castro, Ivana; Thollot, Yaël; Rasuli, Anvar
• Is Part Of: Human vaccines & immunotherapeutics. Volume 13:Issue 11(2017)
• Page Start: 2707
• Page End: 2712
• Publication Date: 2017-11-02
• Subjects: antibody persistence -- Argentina -- hepatitis A vaccine -- single dose -- follow-up -- Argentina; Vaccines -- Periodicals; 615.372
• DOI: 10.1080/21645515.2017.1358326
• Languages: English
• ISSNs: 2164-5515

Abstract

ABSTRACT: This monocenter, descriptive, prospective, non-interventional study evaluated the long-term immune responses following routine vaccination with one or 2 doses of a licensed inactivated hepatitis A (HA) vaccine ( Avaxim® 80U Pediatric ) at age 11–23 months in a cohort of children from Mendoza, Argentina. Antibodies to hepatitis A virus (anti-HAV) were quantified annually up to Y5, and at Y7. Children whose titer decreased to below the seroprotection threshold (defined as an anti-HAV antibody concentration of ≥ 10 mIU/mL in a microparticle enzyme immunoassay up to Y5, or ≥ 3 mIU/mL in an electrochemiluminescence immunoassay at Y7) received a routine booster dose of the same HA vaccine. This report summarizes the data at 7 year after the first vaccination. Of 546 participants initially included, 264 participants remained at Y7 and provided blood samples. Of these, 204 having received one HA primary dose as a toddler were still seroprotected at Y7; titers for a further 7 also having received one HA dose as a toddler fell to below the seroprotection threshold and they therefore received a booster; all 53 having received 2 HA doses as a toddler and still present at Y7 remained seroprotected at Y7. One or 2 primary doses of this HA vaccine in toddlers result in very good persistence of anti-HAV up to 7 year post-first vaccination.