Herd immunity approach ‘would see 800m infected’


Rhoda Odhiambo BBC Africa Health, Nairobi

The Africa Centres for Disease Control (CDC) has warned that more than 800 million Africans could be infected with coronavirus, if the virus is allowed to spread deliberately with the aim of achieving herd immunity.

The projection is a worst case scenario.

This could put the lives of 8.4 million Africans at risk if immunity was to be achieved naturally, Africa CDC added.

Herd immunity is a situation in which a sufficient proportion of a population is immune to an infectious disease through vaccination and/or prior illness to make its spread from person to person unlikely.

Wessam Mankoula, the incident manager for Covid-19 at the Africa CDC, told the BBC that the risk of deliberately giving the virus an avenue to spread will come at a high human cost.

β€œIn a continent of more than 1.2 billion people, this will mean that we will let the infection get to between 720 – 840 million people to reach this herd immunity,” Dr Mankoula said.

“If we have a vaccine, we will be able to control infections. Without it, this will make our healthcare system vulnerable with a huge number of cases. Our hospitals will also be overwhelmed,” he added.

More than 1.5 million people have been exposed to coronavirus in Africa.

World Health Organization (WHO) chief Tedros Adhanom told journalists on Monday that relying on obtaining herd immunity naturally would be scientifically and ethically problematic.

“Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” he said.

“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic.”

The WHO says for immunity to be achieved, at least between 60% to 70% of the population would need to be immune to the virus.

Both the Africa CDC and the WHO say the continent has done well in dealing with the pandemic. They attribute this to the strict lockdowns that were imposed at the early stages of the pandemic.