Medicins Sans Frontières (MSF) has concluded its three-year emergency response to the diphtheria outbreak in Kano State after supporting the vaccination of more than 835,000 children against the disease.

The mass vaccination campaign, conducted in collaboration with the Kano State Ministry of Health, marks the end of MSF’s emergency intervention in one of Nigeria’s largest recorded diphtheria outbreaks.

Diphtheria is a vaccine-preventable bacterial infection that spreads primarily through respiratory droplets or contact with infected wounds. Symptoms include sore throat, fever, swollen lymph nodes and a thick grey membrane in the throat that can obstruct breathing. In severe cases, the disease can damage the heart, nerves and kidneys, while untreated infections are fatal in about 30 per cent of cases, particularly among young children.

The outbreak largely affected children between the ages of five and 14, many of whom were unvaccinated or only partially immunised. Persistent gaps in routine immunisation, overcrowded living conditions, delayed healthcare-seeking and limited access to quality healthcare contributed to the continued spread of the disease.

MSF said its response, which began in early 2023, enabled more than 14,707 children to receive treatment through MSF-run and supported treatment centres using both facility-based and home-based care. Beyond treatment, the organisation strengthened referral systems, disease surveillance, data management, community engagement and vaccination activities to contain the outbreak.

According to the organisation, two rounds of vaccination carried out with the Kano State Ministry of Health resulted in 835,028 children receiving diphtheria vaccines. The first round, which ended on April 27, vaccinated 348,080 children, while the second round, conducted between June 20 and 24, 2026, reached an additional 486,948 children across 20 wards.

MSF Project Coordinator in Kano, Abdoul-Aziz Djibrilla, said although the outbreak had eased significantly, diphtheria remained a serious public health threat.

“Kano experienced a critical diphtheria outbreak that placed enormous pressure on families, healthcare workers and health facilities. Although the number of cases has declined in recent months, mainly due to mass vaccination campaigns, the disease remains a serious health threat to children in Kano, driven by low immunisation coverage, overcrowding, delayed healthcare-seeking and malnutrition,” he said.

Kano was one of the states worst affected by Nigeria’s ongoing diphtheria outbreak. According to the Kano State Ministry of Health, the state recorded more than 31,900 suspected cases and over 1,260 deaths, mostly among children between March 2022 and March 22, 2026.

The figures account for a significant proportion of the 65,759 suspected cases and 2,229 deaths reported nationwide by the Nigeria Centre for Disease Control (NCDC) during the same period.

At the height of the outbreak between late 2025 and early 2026, MSF said health facilities admitted more than 100 children daily for diphtheria treatment, with bed occupancy exceeding available capacity and healthcare workers overwhelmed by demand.

Despite the sharp decline in infections following the vaccination campaigns, the organisation warned that immunity gaps persist, leaving thousands of children vulnerable to future outbreaks.

Djibrilla called for sustained investment in routine immunisation, disease surveillance and timely access to quality treatment. “Continued commitment from health authorities and partners to sustain high immunisation coverage, strengthen surveillance and ensure timely access to quality treatment will be critical to preventing future outbreaks and protecting the lives of children in Kano,” he said.

MSF, which has operated continuously in Nigeria since 1996, currently provides free healthcare services across 10 states and said it remains committed to supporting vulnerable communities through emergency medical interventions whenever needed.