NZ’s Covid-19 reinfections will be driven by BA.5 variant - virologist

Source: 1News

Covid-19 reinfections in New Zealand are going to be driven by the more contagious, immunity-evading Omicron subvariant BA.5, a virologist says.

University of Otago virologist Dr Jemma Geoghegan told Breakfast experts and health authorities expect to see a rise in Covid cases in the coming weeks due to reinfections.

She said the Omicron subvariants of BA.4, BA.5 and others have "clearly" established themselves in the community, with cases of them every week for the last month or so.

Covid-19 Response Minister Ayesha Verrall said last week BA.5 is predicted to become the dominant strain in the country in the coming weeks.

READ MORE: Immunity-evading Covid variant will trigger second wave - experts

At the same time she said the country is remaining at the Orange level of the traffic light system due to Covid-19 case numbers starting to "creep up". Hospitals being under pressure from the flu is also a factor.

The rules around reinfection have also changed. People experiencing Covid-19 symptoms 29 days or more after their initial infection will have to take another test. If it's positive they will need to isolate for seven days.

"This is a change from earlier advice which was that people would not need to re-test if they had tested positive for Covid-19 within the past 90 days and is based on the latest international evidence and the need to isolate quickly people with reinfections," Verrall said.

Household contacts who've had the virus within 90 days still won't need to re-isolate, unless they are symptomatic.

The BA.4 and BA.5 subvariants were first detected in New Zealand in early June.

Geoghegan explained the subvariants were dominating others around the world and New Zealand "is no different". They contain genetic mutations which allow them to overcome the protection of past infection or vaccination, she said.

Reinfections are already being seen in other countries around the world, Geoghegan said, particularly in Portugal and South Africa.

In Britain, new data released on Saturday revealed the number of new Covid cases surged by more than 30% in the last week due to BA.4 and BA.5, despite widespread immunisation.

Geoghegan said with other respiratory illnesses such as flu and RSV circulating it is important people keep up with mask wearing.

On Sunday, 4924 community cases were announced.