Is COVID herd immunity becoming a myth?

Scientists have long said herd immunity is needed to slow down the spread of COVID-19.

That is when 70 percent or more of the population is protected from the virus, either by becoming infected or being vaccinated.

But some experts now doubt it can be achieved because of the contagious Delta variant.

Countries with high vaccination rates, including Israel and the United States, are reimposing restrictions as infections rise.

And herd immunity is far from being achievable in the developing world, where only 1.2 percent of people have received at least one dose of the vaccine.

So will governments need new strategies to control the pandemic?

Presenter: Kim Vinnell

Guests:

Wafaa El-Sadr – Professor of epidemiology and medicine at Columbia University

John Nicholls – Clinical professor in pathology at the University of Hong Kong

Helen Rees – Member of South Africa’s Ministerial Advisory Committee for COVID-19 and vaccines