Abstract
The safety and immunogenicity of a new formulation of the inactivated hepatitis A vaccine, Avaxim(TM), was evaluated in 189 children, aged 18 months to 15 years in a monocentric, open trial. Two vaccinations were given six months apart. Enrollment was balanced within three age groups: 18 months to 3 years, 4-8 years and 9-15 years. Antibody titers were measured blindly by an independent laboratory using a modified radioimmunoassay. Two weeks after the first dose, seroconversion was achieved by 94.6, 94.3 and 96.4% of initially HAV-seronegative subjects (antibody titre < 20 mIU/ml) in each age group (youngest to oldest, respectively), with corresponding geometric mean titre concentrations (GMC) of 72.2, 54.3 and 47.1 mIU/ml. Just before the booster dose, the seroconversion rate was 100% in all groups, and the corresponding GMC values were 163, 169 and 111 mIU/ml. All groups included, a 22.6-fold rise in GMC from prebooster levels was observed four weeks after the booster dose. An explanatory analysis suggested a tendency for higher antibody levels in younger children at all vaccination time points. Local reactions were noted in 18.2% of the vaccinees after the first dose and in 8.5% after the booster dose. The rates of systemic reactions were 23.8% after the first dose and 11.4% after the booster dose. Overall, this trial demonstrated the good safety and immunogenicity profile of this vaccine in children aged 18 months to 15 years of age.
Original language | English |
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Pages (from-to) | 1919-1925 |
Number of pages | 7 |
Journal | Vaccine |
Volume | 17 |
Issue number | 15-16 |
DOIs | |
State | Published - 9 Apr 1999 |
Keywords
- Children
- Hepatitis A vaccine
- Immunogenicity
- Safety
ASJC Scopus subject areas
- Molecular Medicine
- General Immunology and Microbiology
- General Veterinary
- Public Health, Environmental and Occupational Health
- Infectious Diseases