RESUMEN
BACKGROUND: Hepatitis B virus (HBV) infection and its complications are among the most common diseases in Iran. National mass vaccination of neonates against hepatitis B was started in 1991, but was considered a costly venture. AIM: To compare the efficacy of low-dose intradermal HBV recombinant vaccine with standard intramuscular dose in neonates. METHOD: 165 apparently healthy neonates born in Shiraz were randomized to receive either 10 microg [corrected] of recombinant vaccine intramuscularly (IM; n=82) or 2 microg [corrected] vaccine intradermally (ID; n=83) at months 0, 1, 6. Anti-HBs titers were measured at 6 and 18 months after the first dose. RESULTS: 53 and 51 neonates in the IM and ID groups, respectively, completed the study. Protective anti-HBs titers (>10 IU/L) at 18 months after the first dose were achieved in 98.1% and 96.2% of neonates in IM and ID groups, respectively (p=ns). The only side effect in the ID group was local hyperpigmentation, which was seen in 55%; no significant side effect was reported in the IM group. CONCLUSION: Intradermal vaccination with 20% of standard dose is as effective as IM vaccination when evaluated at 18 months after the first dose.