COVID-19: Government makes strongest hint yet at fourth vaccine dose

Four COVID-19 vaccine doses could be on the cards for New Zealanders as Omicron subvariants continue to spread.

Two more cases of the Omicron BA.5 subvariant were found in New Zealand on Monday, taking the total to three. All have recently arrived in the country having travelled from South Africa.

With our borders open to travellers, it means there is more of a threat new variants will arrive.

Epidemiologist Professor Michael Baker said we should be tracking reinfections and he's called for a fourth Pfizer shot for those at most risk.

"I think we should be really looking at rolling out a fourth dose to the most vulnerable now, because they will have, in many cases, had their full vaccination quite early on so their level of protection will be declining," he said.

And COVID-19 Response Minister Chris Hipkins said the Government will soon make an announcement about this.

"It is likely that we will have more to say about that in the next week or two," he said.

Prof Baker said that even if you've had Omicron, you can get it again.

"It appears you can get reinfected very easily with Omicron and it's partly because the different variants or subvariants of this virus, of this variant actually, are succeeding by evading the immunity you already have."

If you've had COVID-19 and someone else in your house gets it, you don't have to isolate for another three months, suggesting you're immune.

"But it's an arbitrary figure, and it's very clear that some people overseas are getting reinfected within a few weeks," Prof Baker said.

BA.4 and BA.5 have caused a spike in cases in South Africa and they could do the same in New Zealand this winter.

COVID-19 modeller Professor Michael Plank said while it's difficult to put a timescale on a spike in cases, it is "quite possible" it could drive a second wave in the coming months.

He also said why it's important for people to stay up to date with their vaccines.

"Because otherwise, even if you've had COVID before, you're risking getting seriously ill the next time around and it is likely that most people will become reinfected for a second and even a third time," Prof Plank said.

Meanwhile, 6407 new COVID-19 cases were reported on Monday - a drop of over 1000 from last Monday.

Two people have died with the virus, both males aged in their 80s. It brings our total death toll to 862.

A total of 368 people are in hospital with the virus, with 18 in the ICU or a high dependency unit.