Safety and Immunogenicity of Live Oral Cholera Vaccine CVD 103-HgR in Children Aged 2–5 Years in the United States

In a phase 4, randomized, placebo-controlled, double-blind, multicenter study, to assess the safety and immunogenicity of live, attenuated cholera vaccine PXVX0200 in children aged 2–5 years in the United States, 172 volunteers were randomized 6:1 to receive a single dose of 1 × 10(9) colony forming units (CFU) of PXVX0200 or placebo. Immunogenicity endpoints included serum vibriocidal antibody (SVA) levels on days 1, 11, and 29. Safety was assessed by comparing solicited signs and symptoms on days 1–8, unsolicited adverse events through day 29, and serious adverse events (SAEs) through day 181. The SVA seroconversion rates 10 days after immunization were 98.1% and 0% in vaccine and placebo recipients, respectively, and the vaccine seroconversion rate was non-inferior to the 93.5% rate seen in the bridging population of adults aged 18–45 years from a lot consistency study. Most reactogenicity was mild to moderate, and there were no study-related SAEs. PXVX0200 appears safe and immunogenic in children aged 2–5 years.