Combined intramuscular-intradermal protocol of universal neonate HB vaccination irrespective of mother's status of HBsAg.

To evaluate a protocol of combined intramuscular-intradermal (i.m.-i.d.) universal hepatitis B (HB) vaccination of neonates regardless of the mothers' HB surface antigen HBsAg status, 160 full-term newborn babies were sequentially divided into groups A and B (test and control groups). The group A babies were immunized by giving 30 micrograms HB vaccine i.m. within 24 h after birth and 2 micrograms i.d. twice at 1 and 6 months of age. Group B babies were immunized by giving one initial dose of 30 micrograms i.m. and two booster doses of 10 micrograms i.m. after same 0, 1, 6-month schedule. Blood samples were collected at birth before the first dose of the HB vaccine, at 6 months of age before the third dose and at 12 months. The blood samples were tested for HBsAg and anti-HBs by using Abbott RIA reagents. All of the 160 newborns received three doses of vaccine, but in only 96 of them was the blood examination completed. The positive rate of anti-HBs > 10 IU l-1 was 76.27 and 83.08% in groups A and B, respectively at 6 months, and 83.72 and 92.45%, respectively at 12 months. The geometric mean titres (GMT) of anti-HBs was 42.25 and 60.25 IU l-1 in groups A and B, respectively at 6 months, and 74.45 and 87.1 IU l-1, respectively at 12 months. HBsAg was negative in the two groups 6 and 12 months after birth. The chi 2 and t-tests showed there were no significant differences in these data between the two groups. Thus was it demonstrated that the combined i.m.-i.d. protocol using 34 micrograms of HB vaccine can produce a protection similar to that of the conventional 50 micrograms i.m. regimen, while ca on-third of the vaccine can be saved. The new protocol is theoretically rational and may be ideal according to the cost-effectiveness principle.