Safety, tolerability, and immunogenicity of an inactivated hepatitis A vaccine: effects of single and booster injections, and comparison to administration of immune globulin.
Hepatitis A virus (HAV) infection in adults is often symptomatic and disabling. The present article summarizes our experience with phase 2 studies of an inactivated hepatitis A virus vaccine. Pre- and post-exposure prophylaxis with immune globulin (IG) is only effective for 4-6 months. We compared the safety, tolerability, and immunogenicity of a single i.m. injection of IG with single and booster doses of an inactivated hepatitis A virus vaccine (iHAV) in adults. A total of 75 healthy volunteers (aged 18-50 years) were evaluated in two separate studies. The first included 15 volunteers who received 25 units iHAV i.m. at 0 and 24 weeks. The second, a randomly controlled study, consisted of three groups receiving 25 units iHAV i.m. at 0, 1, and 6 months, or at 0, 2, and 6 months, or 0.06 ml/kg IG i.m. given once. Anti-HAV seroconversion was measured by radioimmunoassay (RIA). After IG injection, anti-HAV seroconversion occurred in 100% of recipients at week 1, declining to 10% at week 12, and 0% by week 20. In contrast, after a single 25-unit dose, RIA seropositivity in iHAV vaccines was 73% by week 2, reaching 100% by week 5, and persisted in all up to week 24, at which time anti-HAV geometric mean titers (GMT) were 2-fold higher than those seen at week 1 after IG. Administration of a booster dose given 1 or 2 months after primary immunization did not significantly improve the quantitative anti-HAV response at 6 months as compared to the effect of the primary dose.(ABSTRACT TRUNCATED AT 250 WORDS)
Shouval
D
D
Liver Unit, Hadassah University Hospital, Jerusalem, Israel.
Ashur
Y
Y
Adler
R
R
Lewis
J A
JA
Miller
W
W
Kuter
B
B
Brown
L
L
Nalin
D R
DR
D000293:Adolescent; D000328:Adult; D005260:Female; D022362:Hepatitis A Vaccines; D006507:Hepatovirus / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007136:Immunoglobulins / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage*; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology
D022362:Hepatitis A Vaccines; D007136:Immunoglobulins; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines