Persistence of immunity from 1 year of age after one or two doses of hepatitis A vaccine given to children in Argentina
Authors Espul C, Benedetti L, Cuello H, Houillon G, Rasuli A
Received 13 May 2012
Accepted for publication 25 June 2012
Published 28 August 2012 Volume 2012:4 Pages 53—60
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 3
Carlos Espul,1 Laura Benedetti,2 Héctor Cuello,3 Guy Houillon,4 Anvar Rasuli4
1Programa de Lucha Contra las Hepatitis Virales, Ministerio de Salud/Hospital Central de Mendoza, 2Programa Provincial de Inmunizaciones, Ministerio de Salud, 3Laboratorio de Virología, Hospital Central de Mendoza, Mendoza, Argentina; 4Sanofi Pasteur, Lyon, France
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: hepatitis A vaccine, single dose, antibody persistence, immunization programs
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]