Diphtheria is back in Nigeria’s headlines. But the more important story is not that another outbreak has occurred. It is what recurring diphtheria transmission tells us about the capacity of our health system to prevent, detect and respond to diseases we already know how to control.
In early September 2026, Plateau State authorities reported more than 140 suspected diphtheria cases and 23 deaths across several Local Government Areas (LGAs), prompting the temporary closure of primary and secondary schools as part of the containment response. This is not an isolated event. Nigeria has been managing a protracted diphtheria outbreak since 2022. In November 2025, the World Health Organization (WHO) reported 8,587 confirmed cases and 884 deaths nationally in 2025 alone, spread across 240 LGAs in 30 states. WHO attributed the scale of the response challenge to low vaccination coverage, delayed laboratory confirmation, gaps in infection prevention and control, and vaccine shortages.
Diphtheria is vaccine preventable, which changes the question we should be asking.
WHO identifies community-wide vaccination, delivered through routine immunisation at the primary healthcare level, as the most effective way to prevent it. That makes every new cluster of cases more than an epidemiological event; It is a signal that somewhere along the prevention pathway, children and communities are being missed. The question is not only how do we stop the current outbreak, but what allowed so many people to remain vulnerable in the first place.
Routine immunisation is the first line of defence
Outbreak response campaigns matter. They close immunity gaps quickly and protect high-risk communities. But they cannot substitute for a routine immunisation system that works consistently. The real test of an immunisation programme is not what happens during an emergency. It is what happens every ordinary day at the primary healthcare level. Is the vaccine available when a caregiver arrives? Is the health worker present? Does the caregiver know when the next dose is due? Does a child who misses an appointment get followed up? Can health teams identify settlements where children have never received a routine vaccine?
These questions matter because protection against diphtheria requires more than one contact with the health system. WHO notes that multiple doses and booster doses are required to build and sustain immunity. Yet Nigeria’s estimated 2024 coverage was 71% for the first dose of diphtheria-tetanus-pertussis vaccine (DTP1) and 67% for the third dose (DTP3). That four-point gap is not a rounding error: at Nigeria’s birth cohort of roughly 7 million children a year, it represents hundreds of thousands of children who start the immunization series but never complete it.
The zero-dose burden is larger still. In April 2026, UNICEF estimated that approximately 2.2 million children in Nigeria were entirely unvaccinated, the highest number in Africa and among one of the highest globally. Earlier data from the 2021 Multiple Indicator Cluster Survey/National Immunization Coverage Survey (MICS/NICS) found that 18% of children aged 12–23 months had received no routine immunisation, while only 36% had received all recommended vaccines. These figures should make us rethink immunisation as more than a vertical programme. Routine immunisation is a core measure of whether primary healthcare is reaching people consistently and equitably.
Find the children the averages hide
National and state coverage figures can conceal substantial gaps. A state may show moderate average coverage while particular wards, informal settlements, remote communities, mobile populations, or conflict-affected areas remain substantially under-immunised. When these pockets accumulate enough susceptible people, vaccine-preventable diseases spreads. This is precisely the pattern Plateau State’s LGA-level case distribution suggests: outbreaks cluster where coverage gaps cluster, not evenly across a state average.
Health teams need reliable data showing where zero-dose and under-immunised children live, why they are being missed, and what mix of fixed-site services, outreach, community mobilisation and follow-up can reach them. Nigeria is already using approaches like the Periodic Intensification of Routine Immunisation (PIRI) and the Big Catch-Up to locate and vaccinate missed children. who have been missing. The challenge is ensuring these efforts strengthen routine systems rather than temporarily compensate for their absence. The goal should not simply be more doses delivered; it should be a system capable of knowing who has been missing, where they are, and how quickly that gap can be closed.
Surveillance must detect outbreaks before headlines do
Immunisation is one side of prevention. Surveillance is the other. Diphtheria can progress rapidly, and WHO stresses the importance of prompt diagnosis and early treatment. A resilient system depends on frontline workers who can recognise a suspected case, isolate appropriately, notify surveillance teams, collect specimens, initiate referral and support contact management without dangerous delays.
This requires functioning surveillance structures from community to facility, LGA, state and national levels, supported by laboratory capacity, sample transportation, clear reporting channels and data systems capable of turning signals into decisions. WHO has previously highlighted delayed laboratory confirmation and gaps in infection prevention and control as challenges in Nigeria’s diphtheria response. Surveillance should therefore not be seen as an emergency activity switched on after cases increase. It is part of the everyday infrastructure of primary healthcare and health security.
From emergency response to resilient primary healthcare
Nigeria needs rapid outbreak investigation, case management, targeted vaccination, laboratory support, contract tracing and risk communication. But if the response stops there, we will have treated the emergency without addressing what made it possible: reliable vaccine forecasting and distribution, stronger routine immunization, active identification of zero-dose children, supported frontline workers, functional surveillance and laboratories, and consistent infection-prevention practices, all integrated at the primary healthcare level.
Preparedness should not be measured only by how fast we mobilize once an outbreak is declared. It is the missed dose that gets detected and followed up. It is the facility that does not run out of vaccine. It is the community health worker who identifies an unvaccinated household, and the clinician who recognizes a suspected case early. These actions rarely make headlines. But they are what prevent them, and they are the real story behind every diphtheria case Nigeria reports.
Prevention is cheaper than response. More importantly, in the case of diphtheria, prevention is possible.
