title: Immunogenicity and safety in adults of hepatitis A virus vaccine administered as a single dose with a booster 6 months later.
abstract: An inactivated vaccine against hepatitis A was administered as a single 1,440 enzyme-linked immunosorbent assay (ELISA) units dose at month 0 with a booster at month 6 to 200 subjects divided into two age groups: group 1, 20-39 years (n = 134) and group II, 40-62 years (n = 66). At day 15, the seropositivity rates were 90% and 77% in groups I and II, respectively. At month 1 the seropositivity rate was 97% in both groups. At month 6 the seropositivity rates were 94% and 88% in groups I and II, respectively. One month after the booster, at month 7, 100% in both groups had become seropositive. The vaccine was well tolerated and did not cause any severe reactions. The results indicate that a single high vaccine dose offers protection against hepatitis A virus (HAV) for at least 6 months in the majority of cases where rapid vaccination is required even in travellers of older age. A booster dose will ensure long-term protection.
authors.affiliation: Department of Infectious Diseases, Reykjavik City Hospital, Iceland.
authors.forename: H
authors.initials: H
authors.lastname: Briem
authors.forename: A
authors.initials: A
authors.lastname: Safary
mesh_terms: D000328:Adult; D000367:Age Factors; D003257:Consumer Product Safety; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006506:Hepatitis A / Q000276:immunology / Q000517:prevention & control*; D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D017957:Hepatitis A Virus, Human / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000009:adverse effects / Q000276:immunology; 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