Varicella (chickenpox) is a common, highly contagious disease caused by primary infection with varicella zoster virus (VZV), which can result in bacterial superinfection, central nervous system complications, and hospitalization. Stage 2 of this Phase 3 open-label study (ClinicalTrials.gov identifier: NCT03843632) enrolled 100 healthy infants, children, and adolescents (12 months–6 years, n = 37; 7–12 years, n = 33; 13–17 years, n = 30) without a clinical history of varicella. Participants aged 12 months–12 years were administered 1 dose of VARIVAX™ 0.5 mL (Varicella Virus Vaccine Live [Oka/Merck]) and adolescents aged 13–17 years were administered 2 doses 6 weeks apart. For participants seronegative at baseline (VZV antibody titer <1.25 glycoprotein enzyme-linked immunosorbent assay [gpELISA] units/mL), immunogenicity was assessed by seroconversion (VZV antibody titer ≥5 gpELISA units/mL) and VZV antibody geometric mean titers 6 weeks after the final dose. For participants who were VZV seropositive at baseline (VZV antibody titer ≥1.25 gpELISA units/mL), immunogenicity was assessed by antibody titer geometric mean fold rise and percentage of participants with ≥4-fold rise in antibody titer 6 weeks after the final dose. A Vaccine Report Card was used to report solicited and unsolicited adverse events through 42 days post-vaccination. After series completion among seronegative participants across age groups (n = 74), 98.6% demonstrated seroconversion 6 weeks post-vaccination; among seropositive participants (n = 26), 65.4% had ≥4-fold rise in antibody titer 6 weeks post-vaccination. No new safety signals were observed. Administering VARIVAX to infants, children, and adolescents resulted in an acceptable immune response with a safety profile consistent with the licensed product.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.