Victoria has again forced large parts of Melbourne into lockdown, in an attempt to try and halt the spread of coronavirus.

Listing postcodes in so-called "hot zones" where restrictions will apply, Victoria's Premier Daniel Andrews says the "extraordinary steps" were necessary to contain a surge in infections.

The orders effectively place some suburbs back under the same restrictions from the start of the pandemic.

So will it help stop the spread?

On today's show:

* Why are people in Melbourne being forced back into lockdown?

* As cases rise in Victoria, why aren't we seeing more people in hospital like what happened the first time?

* There hasn't been a treatment or vaccine for SARS and MERS, why do we think there will be one for coronavirus?

* There are antiviral drugs for HIV, could we see a similar approach for coronavirus?