Aim: To determine whether or not a low dose of HB vaccine can be effectively used in the rapid vaccination.
Methods: Rapid vaccination (0, 1, 2 months) with low dose (5 microg) or routine dose (10 microg) HB vaccine was studied in 250 subjects (130 school children and 120 university students). Serum from all the participants was tested for HBsAg, anti-HBs and anti-HBc at 1, 3 and 7 months after the first dose of vaccination and all subjects were serum HBV marks negative before the vaccination. Non-responders to a complete initial vaccination from university students were given an additional vaccination with 10 microg of HB vaccine and their serum anti-HBs was tested again one month later.
Results: One month after the third dose of vaccination (third month) sero-conversion rates and geometric mean titer (GMTs) were significantly (P<0.01) higher in the routine dose (resp. 89% and 106.8) than in the low dose group (resp. 72% and 59.5). Sero-conversion rates and GMTs were maintained stable for another 4 months in both groups. After an additional vaccination to non-responders with 10 microg HB vaccine, 17/23 subjects (13/15 from those vaccinated with 5 microg vaccine and 4/8 from those vaccinated with 10 microg vaccine) became anti-HBs positive, yielding similar sero-conversion rates for both dose groups.
Conclusion: Higher sero-conversion rates and GMTs were reached in those vaccinated with 10 microg HB vaccine than in those vaccinated with 5 microg HB vaccine after a complete vaccination with a 0, 1, 2 month scheme. But the subjects vaccinated with 5 microg vaccine can also reach the similar sero-conversion rate after an additional vaccination.