Immunogenicity and Safety of a Newly Developed Live Attenuated Varicella Vaccine in Healthy Children: A Multi-National, Randomized, Double-Blinded, Active-Controlled, Phase 3 Study

Abstract

Korean manufacturers have developed a new varicella vaccine, NBP608. This phase 3, randomized, double-blind, multicenter study aimed to compare the immunogenicity and safety of NBP608 among healthy children to those of VarivaxTM (control). Children aged 12 months to 12 years were randomized 1:1 to receive either NBP608 or control vaccine. Serum samples were obtained before vaccination and within six to eight weeks after vaccination. A total of 499 participants (NBP608, n = 251; control, n = 248) was enrolled. The seroconversion rate (SCR) measured using FAMA assay was 99.53% in the NBP608 group, and the lower limit of the 95% confidence interval (95% LCL) for SCR difference (NBP608 minus control) was 0.52%. This 95% LCL for the difference was higher than the specified non-inferiority margin of –15%. In assessment by gpELISA, the SCR was 99.53% in the NBP608 group; and the 95% LCL for SCR difference was 6.5%, which was higher than the specified non-inferiority margin of –15%. There were no significant differences between the NBP608 and control group with respect to proportions of participants who demonstrated local and systemic solicited AEs. This study indicated that NBP608 had a clinically acceptable safety profile and was not immunologically inferior to VarivaxTM.