Scientists have long said ‘herd immunity’ is needed to control the COVID-19 pandemic.

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

Infections are rising in countries with high vaccination rates, such as Israel and the U.S.

Herd immunity is far from being achievable in the developing world.

So will governments need new strategies?

Presenter: Kim Vinnell

Guests:

Wafaa El-Sadr – Professor of Epidemiology and Medicine, Columbia University.

John Nicholls – Clinical Professor in Pathology, University of Hong Kong.

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

– Follow us on Twitter: https://twitter.com/AJEnglish/

– Find us on Facebook: https://www.facebook.com/aljazeera/

– Check our website: https://www.aljazeera.com/