Comparative immunogenicity of hepatitis B vaccine administered into the ventrogluteal area and anterolateral thigh in infants.

OBJECTIVE

To compare the immunological response of hepatitis B vaccine given by intramuscular injection into the anterolateral thigh and ventrogluteal site of infants up to 10 months old at initiation of vaccination.

METHODS

An open, randomized study of 200 healthy infants recruited from a single practice in a small regional town in New South Wales was carried out. Infants were vaccinated with hepatitis B vaccine (Engerix-B 10 microg) using a 0 months, 1 month, 6 months regimen, with venous blood being collected from children 4-6 weeks after the last dose of vaccine for quantitative determination of hepatitis B surface antibody (anti-HBs) titre. Infants with anti-HBs titre > or = 100 m IU/mL were considered to be 'good' responders and were unlikely to acquire clinically significant hepatitis B infection. Infants with anti-HBs titre < 100 m IU/mL were considered to be 'poor' responders and were given a booster dose of Engerix-B 20 micro g; serology was repeated for anti-HBs titre 2-3 months after this injection.

RESULTS

Quantitative anti-HBs titre was obtained from 177 infants: 171 4-6 weeks after the last dose of vaccine; 87 at the ventrogluteal site (46 boys, 41 girls); and 84 at the anterolateral thigh site (38 boys, 46 girls). Good antibody response (anti-HBs titre > or = 100 m IU/mL) was not significantly different for the two sites (ventrogluteal 96.6%, anterolateral thigh 93.2%), and antibody geometric mean titres (GMT) for anti-HBs were comparable for the two sites (ventrogluteal 2071.2 +/- 5.8m IU/mL, anterolateral thigh 2073.2 +/- 5.2m IU/mL).

CONCLUSION

The ventrogluteal and anterolateral thigh vaccination sites in infants are immunologically comparable for hepatitis B vaccine. Presumably the variance of this study with studies of adults reflected the uniform injection of vaccine antigen into muscle tissue in infants.