Immunogenicity, safety and tolerability of varying doses and regimens of inactivated hepatitis A virus vaccine in Navajo children

Wendy Newcomer, Beth Rivin, Raymond Reid, Lawrence H. Moulton, Mark Wolff, Janne Croll, Carol Johnson, Leora Brown, David Nalin, Mathuram Santosham

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


The Navajo are known to be at high risk for hepatitis A virus (HAV) infection. This study investigated the safety and immunogenicity of an investigational, alum-adjuvanted, formalin-inactivated HAV vaccine (VAQTA) developed by Merck Research Laboratories in Navajo children. One hundred two of 212 children, ages 4 to 12 years, were HAV-seronegative (≤10 mIU/ml by an enhanced sensitivity modification of the HAVAB®; Abbott). Ninety of these children received the HAV vaccine. Study participants were given vaccines containing various viral protein concentrations: Group A (n = 18), 6 units; Group B (n = 36), 13 units; and Group C (n= 36), 25 units HAV protein (1 unit ± 1 ng viral protein antigen). Three-dose (0, 8, 24 weeks) and two-dose (0, 24 weeks) regimens were compared in subgroups within B and C. The vaccine was well-tolerated and there were no serious adverse reactions; no vaccinee developed hepatitis A. After 1 dose 82 to 100% of children seroconverted (≥10 mIU/ml, modified HAVAB®; Abbott) and 100% seroconverted after 2 doses. After 1 dose the geometric mean titer for antibody was: Group A, 22 mIU/ml; Group B, 18 mIU/ml; and Group C, 38 mIU/ml. After 3 doses geometric mean titers increased to 10 106 mIU/ml in Group A, 7258 mIU/ml in Group B and 11 856 mIU/ml in Group C. Further field studies are indicated to evaluate its use in high risk populations, such as the Navajo.

Original languageEnglish (US)
Pages (from-to)640-642
Number of pages3
JournalPediatric Infectious Disease Journal
Issue number7
StatePublished - Jul 1994


  • American indians
  • Hepatitis A
  • Inactivated vaccine

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Microbiology (medical)
  • Infectious Diseases


Dive into the research topics of 'Immunogenicity, safety and tolerability of varying doses and regimens of inactivated hepatitis A virus vaccine in Navajo children'. Together they form a unique fingerprint.

Cite this