title: Determinants of hepatitis A vaccine immunity in a cohort of human immunodeficiency virus-infected children living in Switzerland.
abstract: Vaccination in HIV-infected children is often less effective than in healthy children. The goal of this study was to assess vaccine responses to hepatitis A virus (HAV) in HIV-infected children. Children of the Swiss Mother and Child HIV Cohort Study (MoCHiV) were enrolled prospectively. Recommendations for initial, catch-up, and additional HAV immunizations were based upon baseline antibody concentrations and vaccine history. HAV IgG was assessed by enzyme-linked immunosorbent assay (ELISA) with a protective cutoff value defined as ≥10 mIU/ml. Eighty-seven patients were included (median age, 11 years; range, 3.4 to 21.2 years). Forty-two patients were seropositive (48.3%) for HAV. Among 45 (51.7%) seronegative patients, 36 had not received any HAV vaccine dose and were considered naïve. Vaccine responses were assessed after the first dose in 29/35 naïve patients and after the second dose in 33/39 children (25 initially naïve patients, 4 seronegative patients, and 4 seropositive patients that had already received 1 dose of vaccine). Seroconversion was 86% after 1 dose and 97% after 2 doses, with a geometric mean concentration of 962 mIU/ml after the second dose. A baseline CD4(+) T cell count below 750 cells/μl significantly reduced the post-2nd-dose response (P = 0.005). Despite a high rate of seroconversion, patients with CD4(+) T cell counts of <750/μl had lower anti-HAV antibody concentrations. This may translate into a shorter protection time. Hence, monitoring humoral immunity may be necessary to provide supplementary doses as needed.
authors.affiliation: Department of Pediatrics, Geneva Medical School and University Hospitals of Geneva, Geneva, Switzerland. Claire-Anne.Siegrist@unige.ch
authors.forename: Pierre Alex
authors.initials: PA
authors.lastname: Crisinel
authors.forename: Klara Maria
authors.initials: KM
authors.lastname: Posfay-Barbe
authors.forename: Christoph
authors.initials: C
authors.lastname: Aebi
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Cheseaux
authors.forename: Christian
authors.initials: C
authors.lastname: Kahlert
authors.forename: Christoph
authors.initials: C
authors.lastname: Rudin
authors.forename: David
authors.initials: D
authors.lastname: Nadal
authors.forename: Claire-Anne
authors.initials: CA
authors.lastname: Siegrist
mesh_terms: D000293:Adolescent; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006506:Hepatitis A / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D011446:Prospective Studies; D013557:Switzerland; D014611:Vaccination / Q000379:methods; D055815:Young Adult
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D007074:Immunoglobulin G