There's been a lot of talk over the last several weeks about how the coronavirus variants in Melbourne and Sydney is transmitting in more "fleeting" contact than we've previously seen.

The outbreak in Sydney is the Delta variant and Melbourne's main outbreak was Kappa - and in both cities politicians or health officials say they're seeing people infected in very short periods of time.

So is the virus actually more fleeting - or infectious? Or is it just better contact tracing?

That's on today's Coronacast.

Also on today's show:

* Victoria announces mRNA funding

* It's not looking so good for the next mRNA vaccine candidate

* But it's not all bad - an outbreak in German aged care facility shows us why