Single and booster dose responses to an inactivated hepatitis A virus vaccine: comparison with immune serum globulin prophylaxis.
Pre- and postexposure prophylaxis against hepatitis A virus (HAV) infection with immune serum 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 a single and booster dose of an inactivated hepatitis A virus vaccine (iHAV) in adults. Healthy volunteers (18-50 years) received a single Ig i.m. injection (n = 30), or iHAV i.m. (n = 15) at 0 and 24 weeks, or placebo (n = 4) at the same intervals. Anti-HAV seroconversion was measured by radioimmunoassay (RIA) and neutralizing antibodies by an antigen reduction assay. After Ig injection (0.06 ml/kg), 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 ng dose, RIA seropositivity in iHAV vaccinees was 80% by week 2, reaching 100% by week 5 and persisted up to week 24, at which time anti-HAV geometric mean titres (GMT) were two fold higher than those seen at week 1 after Ig. Postbooster anti-HAV titres in iHAV recipients rose within 4 weeks to 73-fold greater than the peak GMT seen one week after Ig, and 400-fold higher than GMT at 12 weeks after Ig. Neutralizing antibody titres after iHAV followed a similar pattern, as observed for anti-HAV. iHAV was well tolerated; placebo and vaccine tolerability were indistinguishable, with no serious adverse experiences observed. In conclusion, active vaccination with a single iHAV dose may eventually replace Ig for pre-exposure prophylaxis.(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
Armstrong
M E
ME
Davide
J P
JP
McGuire
B
B
Kuter
B
B
Brown
L
L
Miller
W
W
D000293:Adolescent; D000328:Adult; D005260:Female; D006506:Hepatitis A / Q000517:prevention & control*; D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies / Q000097:blood; D006507:Hepatovirus / Q000276:immunology; D006801:Humans; D007117:Immunization, Secondary; D007136:Immunoglobulins / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D012449:Safety; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage* / Q000009:adverse effects
D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies; D007136:Immunoglobulins; D015164:Vaccines, Inactivated; D014761:Viral Hepatitis Vaccines