West Africa grapples with a wave of diphtheria as vaccine coverage slips
West Africa is battling what is thought to be its worst diphtheria outbreak ever recorded – a result of low child vaccination rates which have allowed the deadly infection to tear through the region.
Historically low vaccine coverage in some of Africa’s poorest countries has been made worse still by the disruption of the Covid-19 pandemic and left millions vulnerable.
Nigeria alone has reported more than 12,000 confirmed cases, along with 570 deaths. However, these figures are thought to be a dramatic undercount of the true scale of the flare-up. Outbreaks have also hit Niger, Mauritania and Guinea.
Diphtheria is a highly contagious and potentially fatal bacterial infection affecting the nose and throat.
It should be blocked by routine childhood vaccination, but many parts of Africa, including those hit by the current outbreaks, have for years struggled to deliver jabs to enough of their populations.
Dr Dagemlidet Tesfaye Worku, emergency medical programme manager for the aid charity Doctors Without Borders (MSF) in Ivory Coast, said: “Diphtheria should have been a disease that is confined to the annals of history, we should just be dusting the reports about it for academic interest and personal curiosity.
“But the reality we are facing is sustained, continuous and not properly addressed low vaccination coverage rates.”
Diphtheria is usually immunised against as part of a combined vaccine that also protects against whooping cough and tetanus.
Health experts say at least 80 to 85 per cent of children in a population should receive this jab and its boosters to prevent the occurrence of outbreaks. Latest figures collected by the United Nations children’s body, Unicef, show the level in Africa overall is 84 per cent.
Before the Covid pandemic sucked up health resources and derailed many vaccination programmes on the continent, this figure was 86 per cent.
However, in Nigeria, the continent’s most populous nation with around 225 million people, the rate has long been much lower and is currently only 62 per cent.
More than 2 million Nigerian children have never had a dose of the vaccine, leaving them vulnerable to an infection that can kill as many as half of those infected if proper treatment is not delivered.
Across Africa there is a pool of some 10 million children who have never had the vaccination.
Public health officials say, globally, this group of unvaccinated children has grown over the last three years because the Covid-19 pandemic and ensuing lockdowns diverted resources away from programmes delivering routine jabs, or prevented their rollout.
As a result, more than 60 million children worldwide are estimated to have been left without a single dose of standard childhood vaccines. Another 85 million did not receive their full quota of jabs as a result of the pandemic and are therefore only partially protected.
Dr Claude Ngabu, a West and Central Africa regional health specialist for Unicef, said Covid-19 was “a contributing factor, but not the only one” to the diphtheria outbreak in West Africa.
“Covid-19 had a quite serious impact on the health outcomes for those countries where the immunisation coverage even before Covid-19 were not sufficient.”
Calls for a ‘vaccine blitz’
The number of older children and even adults falling sick in the current diphtheria outbreak has shown the problem of low vaccination rates did not just arise in the past three years, officials say.
Another perhaps bigger factor has been poor health service delivery. Nigeria’s outbreak has hit hardest in some of its poorest states, like Kano, which are starved of health resources.
The fate of the affected countries is worsened by global shortages of the diphtheria vaccine as demand has increased to respond to outbreaks, MSF said.
The charity also said treatment was being held back due to the global shortage of a specific anti-toxin drug, called DAT, needed to reduce the risk of death in diphtheria patients.
Health officials are now calling for a vaccine blitz to reach unprotected children.
“What is needed is a truly massive scale-up of vaccination, as soon as possible,” said Dr Worku.
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