Safety of the novel oral poliovirus vaccine type 2 (nOPV2) in infants and young children aged 1 to <5 years and lot-to-lot consistency of the immune response to nOPV2 in infants in The Gambia: a phase 3, double-blind, randomised controlled trial

Novel Oral Polio Vaccine Type 2 Use for Polio Outbreak Response: A Global Effort for a Global Health Emergency

“…Data from field use and clinical trials support the hypothesis that nOPV2 would have similar immunogenicity and effectiveness to OPV2. Although findings of reduced immunogenicity of nOPV2 in young children when co-administered with bOPV indicated that nOPV2 may be less robust to competition with other enteroviruses in the gut [ 23 ], a study in the Gambia demonstrated excellent seroconversion in infants and young children (63% post-dose 1 in infants seronegative at baseline [n = 499], 65% in children [n = 66]), at levels comparable to those observed in an mOPV2 trial in a similar setting in Mozambique (68% in children seronegative at baseline [n = 75]) [ 10 , 24 ]. In addition, two in-depth studies comparing mOPV2 and nOPV2 effectiveness in Nigeria, which experienced a large cVDPV2 outbreak in 2021 and used the most nOPV2 of any country, found no significant difference between the two vaccines used in outbreak response campaigns [ 19 , 20 ].…”

“…An independent Data and Safety Monitoring Board (DSMB), with representation from global experts from different fields, monitored the safety findings of the EUL-informing studies. PATH sponsored the phase III clinical trial, partnering with Medical Research Council (MRC) Unit—The Gambia, and assisted with regulatory interactions, dossier preparation and coordination of the integrated product development efforts [ 10 ].…”