New Zealand's first new community case of Covid-19 since November has been confirmed as the highly-transmissible South African variant.
The 56-year-old Northland woman almost certainly contracted the virus from another person in managed isolation at Auckland's Pullman Hotel. Investigations are under way into how the virus was transmitted.
The Ministry of Health is due to release an update soon about whether it has spread in the community.
Besides the South African variant, others have been identified in Britain and Brazil.
Here's what we know so far about the coronavirus strain involved in the Northland case.
What is the South African variant?
The South African strain is one of the many mutations of the virus that causes Covid-19.
All viruses mutate, with tiny genetic changes happening as the virus makes new copies of itself to spread and thrive.
Most are inconsequential, and a few can even be harmful to the virus's survival, but some can make it more infectious or threatening to the host - humans.
There are now many thousands of different versions, or variants, of the pandemic virus circulating. But experts' concerns focus on a small number of these.
In December, national authorities in South Africa announced the detection of a variant that was rapidly spreading in three provinces, which they named 501Y.V2.
Also known as B.1.351, it is the dominant virus strain in the Eastern and Western Cape provinces of South Africa, and at least 20 other countries have found cases.
On 21 January, before the Northland community case, New Zealand had recorded 7 cases of the of the South African variant in managed isolation, the Ministry of Health said. The ministry's preliminary concern is that the mutation affects the body's immune response to it and its transmissibility.
Is it more dangerous?
The South African variant appears to be more contagious.
University of Otago virologist Jemma Geoghegan said research suggested the South African variant could be up to 50 percent more transmissible.
There is no clear evidence that variant causes much more serious illness for the vast majority of people who become infected.
But because it is more transmissible, more people could be infected, meaning "proportionally there could be more people in hospital, unfortunately, who die", Geoghegan said.
She said it was not clear if the vaccines would be as effective on the new variants because they were created on genetic sequence from about a year ago.
"Early evidence suggests that some of the viruses that have this mutation might be better at reinfecting people that have recovered or even vaccinated."
What do we know so far about vaccines' effectiveness?
Early laboratory tests in Moderna's Covid-19 vaccine suggest it can recognise and trigger antibodies to both the South African and UK variants of the coronavirus, the company has said.
And scientists have tested the Pfizer vaccine against one of the mutations found in the South African variant, called N501Y, using blood samples from 20 people. In that preliminary study, vaccination appeared to work against the mutated virus.
More studies are needed though, because N501Y is not the only change the South African variant has undergone.
The World Health Organisation says most scientists believe vaccines already approved or in development provide protection against coronavirus variants because they elicit a fairly broad immune response, a host of antibodies and cell-mediated immune responses.
However the WHO, too, is cautious, pointing out that studies are still going on in labs around the world to confirm this.
Watch WHO chief scientist Dr Soumya Swaminathan on vaccines and the coronavirus variants:
What action is NZ taking?
Voluntary Covid-19 saliva testing is being offered to border workers in quarantine facilities, in addition to the regular weekly testing, in response both to the appearance of the more contagious variants and higher infection rates overseas.
The government introduced day 0/1 test and pre-departure testing for all passengers, with the exception of those from Australia, Antarctica and most Pacific Islands, on 15 January.
That is in addition to day 3 and day 12 tests in managed isolation facilities.
Ministry of Health advice on the Northland community case involving the South African variant:
- There are now over 30 locations of interest listed on the Ministry of Health website.
- If you were at the locations of interest at the times stated, you need to; isolate away from others, call Healthline 0800 358 5453 for advice on when and where to get tested, and remain isolated until you have a negative test result.
- If you were not at a location of interest at the stated times and you have no symptoms you do not need to be tested.
- If you were not at any of the locations of interest at the stated times, but you have symptoms, call Healthline for advice on 0800 358 5453
- If you recently arrived in New Zealand and stayed in managed isolation at the Pullman Hotel between 9 January and 24 January, please Isolate away from others, call Healthline 0800 358 5453 for advice on when and where to get tested, and remain isolated until you have a negative test result.
- If you are going to get tested, remember you may have to queue. Please take food and water and continue to be kind to each other and our public health team.
- Remember our hospitals are extremely safe. People who need urgent healthcare (including non-COVID) please continue to call 111 or go to the Emergency Department
- Everyone should continue to scan QR codes using the COVID Tracer app and turn Bluetooth on to help stop the spread of Covid-19.
- BBC / RNZ / Reuters / WHO / Ministry of Health
