Investigation on the effects of booster immunization of human diploid cell rabies vaccine after eight years of primary vaccination

Abstract

Objective To disclose the effects of booster immunization of human diploid cell rabies vaccine (HDCV) after eight years of primary vaccination. Methods Sixty subjects who had participated the phase Ⅲ clinical trial of freeze-dried HDCV were selected and gaven booster immunization after eight years of primary vaccination. The side effects of booster immunization were observed. The serum before and after 14 days of booster immunization were collected and detected the rabies virus neutralizing antibody (RVNA) by rapid fluorescent focus inhibition test (RFFIT). The positive rate and geometric mean titer (GMT) of RVNA before and after booster immunization were made statistical analysis. Results Total 54 subjects finished the follow-up and RVNA detection. No sever side-effects were observed in 30 min or 15 days of follow-up after booster immunization. The positive rate of RVNA before and after booster immunization were 51.85% (28/54) and 96.30% (52/54). The GMT of RVNA before and after booster immunization were 1.42 IU/ml and 30.61 IU/ml. Conclusions The freeze-dried HDCV has good immune effects with one-dose of booster immunization after eight years of primary vaccination. Key words: Rabies; Human diploid cell rabies vaccine (HDCV); Rapid fluorescent focus inhibition test (RFFIT); Neutralizing antibody