ABSTRACT
To study the immunogenicity and reactogenicity of an inactivated hepatitis A vaccine, 204 healthy individuals were randomized into three equal groups, each to receive a different vaccine lot. Each subject received a total of three doses, each of 720 ELISA units of hepatitis A vaccine HM175, according to a 0 and 1 month primary vaccination schedule, with a booster dose given at month 6. Side effects were low and were < 30% after the second injection. All subjects but one had antibodies to hepatitis A virus two months after the first dose of vaccine. At month 6 all vaccinees had seroconverted. There were no differences between the three vaccine lots with respect to side effects, seroconversion rates and geometric mean titre of antibodies. We conclude that the three lots of inactivated hepatitis A vaccine are safe, well tolerated and equally immunogenic.
Subject(s)
Hepatitis Antibodies/biosynthesis , Hepatovirus/immunology , Viral Hepatitis Vaccines/immunology , Adult , Enzyme-Linked Immunosorbent Assay , Female , Germany , Hepatitis A/prevention & control , Hepatitis A Antibodies , Hepatitis A Vaccines , Hepatitis Antibodies/blood , Humans , Immunization Schedule , Immunization, Secondary , Male , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/adverse effects , Vaccines, Inactivated/immunology , Viral Hepatitis Vaccines/administration & dosage , Viral Hepatitis Vaccines/adverse effectsABSTRACT
We investigated immunogenicity, reactogenicity and consistency of three consecutive lots of an inactivated hepatitis A vaccine in 204 seronegative volunteers. Each volunteer received a total of three doses of vaccine (720 EIU) according to a 0, 1 month primary vaccination schedule with a booster dose given at month 6. Mild, moderate and mostly local side effects were reported in 49.7% after the first and in less than 30% after the third injection. Seroconversion rate after one vaccine dose was as high as 91%. All subjects but one had already seroconverted by 1 month after the second injection, corresponding to a seroconversion rate of 99%. The geometric mean titres (GMT) increased with each dose of vaccine administered. Our results show that this inactivated hepatitis A vaccine is highly immunogenic, safe and well tolerated. Furthermore, there were no significant differences between the three vaccine lots in respect to seroconversion rate, size of antibody titre or reactogenicity.
