Safety and immunogenicity of shorter interval schedules of the novel oral poliovirus vaccine type 2 in infants

The World Health Organization has granted emergency use authorization for the novel oral poliovirus vaccine type 2 (nOPV2) to combat outbreaks of vaccine-derived poliovirus type 2. A study involving 905 infants assessed the safety and immunogenicity of nOPV2 with 1-week, 2-week, and 4-week dosing intervals. Results indicate non-inferiority in immunogenicity between 2-week and 4-week schedules. Immunization with nOPV2 at 1-week intervals showed marked responses, suggesting flexibility in vaccination campaigns to enhance coverage during outbreaks. The vaccine was well-tolerated with no severe adverse events, supporting its use to protect vulnerable populations.