Will Infant Hepatitis B Vaccination Protect Into Adulthood?: Extended Canadian Experience After a 2-, 4- And 6-Month Immunization Schedule
M Pinto et al. Pediatr Infect Dis J 36 (6), 609-615. 6 2017. more
Michelle Pinto 1 , Meena Dawar , Mel Krajden , Monika Naus , David W Scheifele
· 1 From the *Vaccine Evaluation Center, Vancouver, British Columbia, Canada; †University of British Columbia, Vancouver, British Columbia, Canada; ‡Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada; and §BC Centre for Disease Control, Vancouver, British Columbia, Canada.
Background: Hepatitis B virus (HBV) vaccination programs generally target infants to prevent chronic HBV infection and/or preadolescents to reduce transmission in adulthood. To assess whether infant HBV immunization can potentially accomplish both objectives, we measured residual immunity 10-16 years after vaccination in Canadian children.
Methods: A prospective, parallel group, single center study enrolled adolescents given HBV vaccine at 2, 4 and 6 months of age. Exclusion criteria included prior HBV infection and additional vaccinations. At follow-up anti-HBs testing, participants were 10-11 or 15-16 years old; those with
Results: A total of 137 tested participants were 10-11 and 213 were 15-16 years old, respectively; none had evidence of prior HBV infection. At baseline, 78% of younger and 64% of older participants had
Conclusions: After HBV vaccination at 2, 4 and 6 months of age, most adolescents had little or no residual antibody but nearly all responded to HBV challenge, confirming immune memory persistence. However, anamnestic responses were weaker in 15- to 16-year olds and lost in some. Booster responses in 10- to 11-year olds were vigorous in comparison. Extended evaluation of protection is warranted.