The sub-variant of Omicron, known at the moment as BA2, is being blamed for a rise in cases in NSW and likely in other states and territories.

And overseas, Hong Kong is struggling with a wave which is killing more and more people due to low levels of vaccination in high risk age groups.

So what could the sub-variant mean for Australia as the weather slowly cools down and we enter darker, cooler times?

Also on today's show:

* China goes into lockdown in several big cities

* Australian researchers have uncovered resistance mutations to Sotrovimab