Hepatitis A vaccine. A new convenient single-dose schedule with booster when long-term immunization is warranted.
A total of 162 anti-HAV-negative healthy adults were immunized with a single high dose (1440 ELISA units = 1 ml) of inactivated hepatitis A vaccine and a booster was given at month 6. Antibodies were measured after modification of a commercial ELISA kit, enabling quantification of titres down to 6 mIU ml-1. After 14 days, 96% of vaccinees had positive anti-HAV titres (> 20 mIU ml-1), and after 30 days all vaccinees had seroconverted. The geometric mean titres were 150 mIU ml-1 and 380 mIU ml-1 respectively. The booster dose at month 6 elicited a dramatic (25-fold) increase in antibody titres from 125 to 3090 mIU ml-1. Thus a single dose may be a convenient alternative to immunoglobulin for inducing rapid seroprotection, with a booster dose at month 6 ensuring long-lasting protection.
Victor
J
J
Department of Infectious Diseases, Rigshospitalet, Copenhagen N, Denmark.
Knudsen
J D
JD
Nielsen
L P
LP
Fomsgaard
A
A
Thybo
S
S
Bygbjerg
I
I
Westh
H
H
D000293:Adolescent; D000328:Adult; D022362:Hepatitis A Vaccines; D017957:Hepatitis A Virus, Human / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000096:biosynthesis; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology
D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies; D014761:Viral Hepatitis Vaccines