Wits University Professor of Vaccinology Shabir Madhi is of the opinion that herd immunity
will not be achieved in various countries including South Africa.
Herd immunity is when a large proportion of a population becomes immune to an infectious disease.
This makes the spread of the disease from person to person less likely.
Madhi says the problem with the current generation of COVID-19 vaccines
is that they vary in terms of how well they work in protecting individuals against infection.