“With any infectious disease, particularly respiratory ones such as coronaviruses, a primary public health goal is herd immunity,” says Dr Silva.

But Dr Silva says a vaccine, which could be 18 months away, is one of the best and safest ways to do that.

“One thing is to introduce a vaccine to build up community resistance with an eye toward herd immunity. The other is to let a gnarly virus happily spread about,” he says.

“With a vaccine, there isn’t the element of sacrificing a segment of your people.”

via What is herd immunity and could it slow the spread of coronavirus COVID-19 around the world? – ABC News (Australian Broadcasting Corporation)