title: Safety, tolerability and immunogenicity of a formalin-inactivated hepatitis A vaccine (VAQTA) in rural Kentucky children.
abstract: This study evaluated the immunogenicity and safety/tolerability profile of an investigational formalin-inactivated hepatitis A virus vaccine (VAQTA; Merck Research Laboratories) in 150 seronegative healthy children, 4 to 12 years old. The vaccine was derived from virus grown in infected MRC-5 cells in either roller bottles or Nunc cell factories (Nunc, Denmark). Subjects were vaccinated intramuscularly in a two dose regimen initially and at 24 weeks: Group A (n = 50) with a 12-unit dose from a roller bottle lot; Group B (n = 50) with a 25-unit dose from another roller bottle lot; and Group C (n = 50) with a 25-unit dose from a Nunc cell lot. Sera for anti-hepatitis A virus antibodies were drawn 3 weeks before vaccination and 4, 24 and 28 weeks after the first dose. Seroconversion from < 10 mIU/ml to > or = 10 mIU/ml by modified HAVAB (Abbott Laboratories) was observed in 99% of subjects at week 4 and persisted in 100% of subjects at week 28 (4 weeks after the second dose). The ranges of geometric mean titers of anti-HAV for all subjects at weeks 4, 24 and 28 were 31 to 49, 51 to 79 and 7059 to 29,609 mIU/ml, respectively. The 12- and 25-unit dose levels of roller bottle yielded similar geometric mean titers. The rise in geometric mean titers after the booster dose was > 120-fold and was highest in the recipients of the 25-unit Nunc cell lot (P < 0.05 for Group C vs. B).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Kentucky Pediatric Research, Inc., Bardstown 40004.
authors.forename: S L
authors.initials: SL
authors.lastname: Block
authors.forename: J A
authors.initials: JA
authors.lastname: Hedrick
authors.forename: R D
authors.initials: RD
authors.lastname: Tyler
authors.forename: R A
authors.initials: RA
authors.lastname: Smith
authors.forename: G
authors.initials: G
authors.lastname: Calandra
authors.forename: C
authors.initials: C
authors.lastname: Patterson
authors.forename: J
authors.initials: J
authors.lastname: Lewis
authors.forename: R
authors.initials: R
authors.lastname: Sitrin
authors.forename: W
authors.initials: W
authors.lastname: Miller
authors.forename: S
authors.initials: S
authors.lastname: Schwartz
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies / Q000097:blood; D006507:Hepatovirus / Q000276:immunology*; D006801:Humans; D008297:Male; D012423:Rural Health; D015164:Vaccines, Inactivated / Q000009:adverse effects; D014761:Viral Hepatitis Vaccines / Q000009:adverse effects* / Q000276:immunology
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies; D015164:Vaccines, Inactivated; D014761:Viral Hepatitis Vaccines