Persistence of immunity from 1 year of age after one or two doses of hepatitis A vaccine given to children in Argentina
Open Access
- 1 August 2012
- journal article
- Published by Informa UK Limited in Hepatic Medicine: Evidence and Research
- Vol. 4, 53-60
- https://doi.org/10.2147/hmer.s33847
Abstract
Background: This study was done to determine the immunogenicity of a single dose of hepatitis A vaccine in children, providing needed clinical data on the flexibility of booster administration. Methods: Participants had received one dose of inactivated hepatitis A vaccine (Avaxim™ 80 U Pediatric) at 12–23 months of age or two doses of the same vaccine at 12 and 18 months of age prior to enrolment. Anti-hepatitis A antibody concentrations were measured at the first, second, and third year after vaccination. Suspected cases of hepatitis A in participant families were assessed and family socioeconomic data were collected. Results: A series of 546 participants were enrolled. Of 467 (85.5%) participants completing 3 years of follow-up, 365 had received a single vaccine dose and 94 had received two vaccine doses. Seropositivity (anti-HAV ≥ 10 mIU/mL) at 3 years was 99.7% after one dose and 100% after two doses. At one year, geometric mean concentrations were higher after two doses (1433.9 mIU/mL, 95% confidence interval [CI] 1108–1855) than one (209.7 mIU/mL, 95% CI 190.6–230.6). Geometric mean concentrations decreased in both groups during the study, but remained well above 10 mIU/mL through the third year. The geometric mean of 3-year to one-year anti-hepatitis A concentration ratios was 0.74 (95% CI 0.70–0.79) following one dose and 0.57 (95% CI 0.47–0.70) following two doses. The greatest decrease in geometric mean concentrations occurred during the third year, ie, 21.2% in the one-dose group and 40.8% in the two-dose group. Six participants became seronegative during follow-up and responded strongly to a booster dose. Anti-hepatitis A concentrations increased in 135 children (34.9%) in the second year and 50 (13.7%) in the third year; none lived in a family with a case of hepatitis A. Three confirmed cases of hepatitis A occurred in family members. Participants belonged to a middle-income, urban/suburban population with good sanitation facilities and water supplies. Conclusion: A single dose of hepatitis A vaccine at 12–23 months of age resulted in hepatitis A seropositivity in all but one vaccinee after 3 years. Increased anti-hepatitis A serum concentrations suggested exposure to wild-type hepatitis A virus in this middle-class socioeconomic environment. Continuing surveillance is required to confirm the effectiveness of a single-dose hepatitis A vaccination; however, the results of the first three years are encouraging.Keywords
This publication has 29 references indexed in Scilit:
- Antibody persistence and immune memory in adults, 15 years after a three‐dose schedule of a combined hepatitis A and B vaccineJournal of Medical Virology, 2011
- Decline in HAV-associated fulminant hepatic failure and liver transplant in children in Argentina after the introduction of a universal hepatitis A vaccination programHepatic Medicine: Evidence and Research, 2011
- Persistence of Antibody to Hepatitis A Virus 10 Years after Vaccination among Children and AdultsThe Journal of Infectious Diseases, 2008
- The need for an evidence-based decision-making process with regard to control of hepatitis AJournal of Viral Hepatitis, 2008
- Long-term immunity in young adults after a single dose of inactivated Hepatitis A vaccinesVaccine, 2006
- Person-to-Person Transmission of Hepatitis A Virus in an Urban Area of Intermediate Endemicity: Implications for Vaccination StrategiesAmerican Journal of Epidemiology, 2005
- Immunogenicity of an inactivated hepatitis A pediatric vaccine: three-year post-booster follow-upVaccine, 2005
- The effects of socioeconomic development on worldwide hepatitis A virus seroprevalence patternsInternational Journal of Epidemiology, 2005
- Hepatitis A vaccine: Indirect evidence of immune memory 12 years after the primary courseJournal of Medical Virology, 2003
- Serum Neutralizing Antibody Response to Hepatitis A VirusThe Journal of Infectious Diseases, 1983