title: Long term follow-up study to evaluate immunogenicity and safety of a single dose of live attenuated hepatitis a vaccine in children.
abstract: Worldwide, viral hepatitis continues to be a cause of considerable morbidity and mortality. Mass immunization with a single dose of live attenuated HAV has been shown to significantly reduce disease burden in the community. This was a phase IV, 5-year follow up study carried out at 4 centers (Kolkata, Delhi, Mumbai and Chennai) across India. The subjects with antibody titer <20 mIU/mL at baseline were evaluated for long term immunogenicity. Of the 503 subjects enrolled, 349 subjects were baseline seronegative with an anti-HAV antibody titer <20 mIU/mL. Overall, 343 subjects could be followed up at some point of time during this 5 y post vaccination period. In the last year (60 months) of follow-up, 108 subjects (97.3%) of 111 subjects (who came for follow-up at the end of 5 y) had a protective antibody titer (anti-HAV antibody titer >20 mIU/mL). The seroconversion rates considering seroprotection levels of anti-HAV antibody titer >20 mIU/mL, following vaccination starting from 6 weeks, 6 months, 12 months, 24 months, 36 months, 48 months and 60 months were 95.1%, 97.9%, 98.3%, 96.2%, 97.8%, 92.6% and 97.3%, respectively. The geometric mean concentration (GMC) over the years increased from 64.9 mIU/mL at 6 weeks to 38.1 mIU/mL and 135.2 mIU/mL at 6 months and 12 months, respectively and was maintained at 127.1 mIU/mL at 60 months. In conclusion, the result of this 5-year follow up study showed that the single dose of live attenuated vaccine is well tolerated and provides long-term immunogenicity in healthy Indian children.
authors.affiliation: a Institute of Child Health ; Kolkata , India.
authors.forename: Monjori
authors.initials: M
authors.lastname: Mitra
authors.forename: Nitin
authors.initials: N
authors.lastname: Shah
authors.forename: Mma
authors.initials: M
authors.lastname: Faridi
authors.forename: Apurba
authors.initials: A
authors.lastname: Ghosh
authors.forename: V S
authors.initials: VS
authors.lastname: Sankaranarayanan
authors.forename: Anju
authors.initials: A
authors.lastname: Aggarwal
authors.forename: Suparna
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Nisha
authors.initials: N
authors.lastname: Bhattacharyya
authors.forename: Ganesh
authors.initials: G
authors.lastname: Kadhe
authors.forename: Gaurav
authors.initials: G
authors.lastname: Vishnoi
authors.forename: Amey
authors.initials: A
authors.lastname: Mane
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006506:Hepatitis A / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood*; D022362:Hepatitis A Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D006801:Humans; D007194:India; D007223:Infant; D008297:Male
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines
keywords: Aes, Adverse events; CDC, Center for Disease Control and Prevention; CIs, Confidence intervals; GMC, Geometric mean concentration; WHO, World Health Organization; antibody; children; hepatitis A; immunization; live attenuated vaccine