The world passed a grim milestone a few days ago: 5 million deaths from COVID-19 and counting.

But the reality is, that the actual deaths from the pandemic are much, much higher.

Estimating how high is hard, but researchers can use data around excess deaths - ie, an increase beyond the normal number of people who die on average year to year - as a guide.

So on today's Coronacast, why reported COVID deaths are probably grossly underestimated.

Also on today's show:

* Australia's vaccination rate starts to slow

* Who are we missing in relation to vaccination?