A clinical trial of lyophilized BCG vaccines for intradermal injection

Abstract

Objective To investigate safety and immune effect of lyophilized BCG vaccines produced by 2 working seed lots in a clinical trial.Methods One hundred healthy subjects aged 3 months to 50 years old with negative purified protein derivative (PPD) skin test and 205 neonates were immunized with the 2 test vaccines and a control vaccine.Local and systemic reactions were investigated and BCG scar size was measured.PPD skin test was performed in the neonatal infants.x2 and t tests were adopted for comparison of BCG scar sizes and PPD test results among 3 neonatal groups.Results No local or systemic adverse reactionswere observed in all subjects.In the neonates,the average diameters of BCG scar and PPD induration were ≥4.6 mm and ≥6.8 mm,respectively.Both the positive rates of BCG scar and PPD test were ＞90％.No statistically significant differences in the positive rates of BCG scar and PPD test were found among 3 neonatal groups (x2 =0.001 ～ 1.713,P =0.191 ～ 1.000).The average diameters of BCG scar and PPD induration were no significantly different between 2 test vaccine groups (t =0.773,P =0.441 ; t =0.226,P =0.822),but the statistical differences were observed between the control group and 2 test groups (t =2.645 ～ 3.361,P=0.001～0.010).Conclusion The lyophilized BCG vaccines prepared by two working seed lots are proved to be safe and immunologically effective for human immunization. Key words: BCG vaccine; Working seed lot; Safety; Vaccination