The humanitarian medical organisation Médecins Sans Frontières in collaboration with the Borno State Ministry of Health, has completed a large-scale vaccination campaign against diphtheria targeting children under 14 years in Maiduguri Metropolitan Council, as Nigeria battles one of its worst outbreaks of the disease in recent history.
In a statement issued on Thursday, the MSF noted that the vaccination campaign reached hundreds of thousands of vulnerable children in the state capital, a major epicentre of the outbreak.
According to the organisation, the first round of the campaign, held from February 9 to 15, exceeded expectations by vaccinating about 490,000 children, surpassing the initial target of 387,000.
“A follow-up round carried out from April 9 to 15 focused on strengthening immunity among 360,000 of those previously reached.”
Despite the scale of the intervention, MSF noted that limited vaccine availability constrained the full scope of the response.
“This vaccination will help to significantly boost the immunity levels of children below 14 years old in Maiduguri, the area responsible for most of the diphtheria cases we saw in our treatment centre.
“This proactive step is essential to controlling and preventing the disease,” MSF said in the statement, quoting its emergency coordinator, Nao Muramoto.
Nigeria has been grappling with a prolonged diphtheria crisis, with the Nigeria Centre for Disease Control and Prevention reporting 65,759 suspected cases and 2,229 deaths as of March 22, 2026, since the outbreak began in May 2022 and was officially declared in 2023.
Borno State remains among the hardest-hit areas, driven by gaps in routine immunisation, population displacement, and limited healthcare access due to years of insecurity.
MSF disclosed that it has treated more than 7,400 suspected diphtheria cases in the state since 2023, including 4,200 cases in the past year alone.
Diphtheria, an acute bacterial infection, spreads through respiratory droplets or contact with infected wounds. It typically presents with symptoms such as sore throat, fever, swollen lymph nodes, and a thick, grey membrane in the throat that can obstruct breathing.
In severe cases, the toxin produced by the bacteria can damage vital organs, including the heart and kidneys, and may lead to paralysis. Health experts warn that the disease can be fatal in up to 30 per cent of untreated cases, particularly among unvaccinated children.
MSF said it provided extensive logistical support for the campaign, including vaccine storage, transportation, supervision of vaccination teams, and community sensitisation efforts, while the Borno State Ministry of Health supplied the vaccines.
The organisation added that the vaccination drive also led to increased case detection, with a surge in patients presenting at the diphtheria treatment unit in Maiduguri Teaching and Training Hospital, reflecting improved awareness and referrals by community health workers.
Beyond Borno, MSF is currently supporting diphtheria response efforts in Bauchi, Kano, and Sokoto states, where thousands of suspected and confirmed cases are being managed in partnership with state authorities.
“Sustained routine immunisation against diphtheria, improved access in volatile areas and tackling vaccine hesitancy remain essential to prevent future surges of vaccine-preventable diseases like diphtheria,” the organisation said.
“Access to more vaccines is needed, as efforts to reach the children of Borno State should remain a priority to avoid further contaminations, to cut transmission and save lives,” MSF added.
Public health experts say Nigeria’s diphtheria outbreak underscores longstanding weaknesses in immunisation coverage, particularly in conflict-affected northern regions, where disrupted health systems and misinformation have continued to hinder vaccine uptake.
They warn that without sustained investment in routine immunisation and emergency response capacity, the country risks recurring outbreaks of preventable diseases.