This multicenter trial is the first-in-human assessment of two novel oral polio vaccines for poliovirus type 1 and type 3. It will be an 8-arm, randomized, observer-blind, controlled trial, with Sabin monovalent vaccines serving as the control for each type. One hundred and fifty to 230 healthy, adult participants will be recruited, 70-80 participants with an exclusive inactivated poliovirus vaccine (IPV) prior vaccination history and 120-150 participants with an oral poliomyelitis vaccine (OPV)-containing prior vaccination history.
The purpose of this study is to assess the safety (primary objective) and immunogenicity (secondary objective) and fecal shedding of vaccine viruses (secondary objective) of two novel oral polio vaccines, nOPV1 and nOPV3, as compared to Sabin monovalent vaccine controls, in 150-230 healthy adults.