The federal government has reported an active diphtheria outbreak in 25 Local Government Areas (LGAs) in four states, including Bauchi, Katsina, Yobe, and Kaduna. The Federal Ministry of Health is working with the National Primary Healthcare Development Agency (NPHCDA), the Nigeria Centre for Disease Control (NCDC), states, and partners to effectively check the outbreak. A comprehensive response plan has been activated to ensure early detection, containment of cases, and preventing further transmission through a multi-phased response strategy. The 171 LGAs in 14 states are at high risk of further spread. The partnership aims to achieve intensified mass vaccination of identified populations at risk to curb the ongoing diphtheria outbreak. The immediate phase one response 5-days reactive catch-up campaign is planned for the affected 25 LGAs in four states from August 7th, targeting children under 14 years old. The full three rounds of the catch-up campaign are being prioritized in 14 states. The risk of death is higher in partially vaccinated or unvaccinated children.