There are two pathways to herd immunity: natural infection or vaccination, explains Reuters.

Natural infection refers to when a large number of people have had a disease and recovered. However, the extent of protection via natural infection is unknown with the new coronavirus. Moreover, more people would die while waiting for herd immunity than if a vaccine was produced.

“The risk is not acceptable,” said Catherine Bennett, epidemiology chair in the Faculty of Health at Melbourne’s Deakin University. “We can’t afford to have people infected to reach herd immunity when we know so little about the longer-term effects.”

Vaccination can provide widespread immunity faster and more reliably.