Early in the pandemic, the term ‘herd immunity’ hit the headlines, along with a polarised discussion on how to achieve it.

Some groups were attached to the now-discredited notion of letting a dangerous virus rip through the population to reach the critical level of population immunity needed to reduce transmission.

But a more serious conversation focused on the prospect of attaining herd immunity by vaccination.

This is the idea that vaccines — when available and taken up at sufficient levels — could squash virus transmission. This would lead to the possible elimination or eradication of SARS-CoV-2, the virus that causes COVID.