Vaccinations for up to 12 million children to prevent the spread of polio in Africa will be delayed, in a major redeployment of polio eradication resources to fight the spread of the Covid-19 pandemic.

Polio prevention campaigns, which are vital to avert outbreaks, will be suspended until at least the second half of 2020, said Dr Pascal Mkanda, the head of polio for World Health Organization Africa. The decision will inevitably lead to a rise in polio cases.

“We took the difficult decision to suspend these plans and considered it would have a significant impact on preventing the spread of new outbreaks,” he said. “New outbreaks of polio will appear because we will not be able to administer the vaccines in time.”

The move is the “right decision”, Mkanda said, “because we need to tackle Covid-19 and because the process of administering vaccinations can actually increase the spread of the virus”.

The effect of the lack of vaccinations has already begun to emerge. On Saturday, Niger reported two new polio cases, affecting children in the capital, Niamey, and the Tillabéri region, according to the WHO. The cases are the first in the west African country since an outbreak which lasted two years was eradicated last December.

“Niger stopped the previous polio outbreaks by mounting high-quality mass vaccination campaigns,” Mkanda said.

The country is one of 15 in Africa experiencing “vaccine-derived poliovirus outbreaks”, with cases spreading among parts of the populations yet to receive a vaccination.

Polio, a highly infectious disease that spreads through contaminated water or food, often affects children under five, with about one in 200 infections leading to paralysis. Of those paralysed, up to 10% die because of crippled breathing muscles.

More than 95% of populations need to be immunised for polio to fully be eradicated.

The increase and success of preventive vaccination campaigns around the world – particularly in Africa and Asia, where the disease has been a scourge – had given international health authorities hope that polio could be eradicated. Yet the Covid-19 pandemic has significantly set back efforts.

Administering the oral polio vaccines would put patients at risk of contaminating Covid-19, the WHO said.

Profile What is the World Health Organization? Show The World Health Organization (WHO) was founded on the 7 April 1948, a date celebrated annually as World Health Day. As an agency of the United Nations, the organisation has developed into an international establishment which involves 150 countries and employs 7,000 people. WHO is responsible for the World Health Report and the World Health Survey. Since its establishment it has played a fundamental role in the eradication of smallpox, and currently prioritises diseases including HIV/AIDs, Ebola, Malaria and Tuberculosis. WHO takes a global responsibility for the co-ordinated management and handling of outbreaks of new and dangerous health threats - like the Covid-19 coronavirus. The current WHO director general is Dr Tedros Adhamon Ghebreyesus, elected for a five year term in 2017. Prior to his election, Dr Tedros served as Ethiopia’s minister for foreign affairs. He also served as minister of Health for Ethiopia from 2005-2012 where he led extensive reform to the country’s health system. WHO's handling of the global pandemic has been criticised by US president Donald Trump, who announced in April that the US will no longer contribute to funding the agency. Grace Mainwaring and Martin Belam

WHO teams focused on testing, contact tracing and social awareness to prevent polio have been entirely redeployed to help with coronavirus.

“What we are doing now on polio is to work very hard on preparedness and planning to be able to do more effective campaigns and really jump in as soon as the Covid-19 response activities have been stopped,” Mkanda added.

The total number of Covid-19 infections in Africa is rapidly increasing – more than doubling in the last two weeks to 32,000 – with a similar increase in the number of deaths, to 1,400.

Concerns that an outbreak could pose profound challenges to their health systems led many African governments to adopt early and aggressive measures to contain it.

WHO officials on polio as well as other related health campaigns have been pooled to support health agencies across Africa.

• This article was amended on 1 May 2020. The standfirst of an earlier version said “jabs” were delayed; this has been changed to reflect the oral administration of the vaccines.