New Covid-19 variant will enter NZ – expert
A new, more infectious, variant of the Covid-19 virus identified in the UK is highly likely to make it to New Zealand’s borders, says an expert.
The new variant is being blamed for faster-than-expected spread of Covid-19 in London, the southeast and east of England, which have been placed into tighter restrictions over the Christmas holidays.
Several other countries have halted flights from the UK in a bid to stop it spreading further.
But the Ministry of Health said yesterday the specific new strain identified in the UK had not yet been seen in this country.
Experts in the UK have said there’s no evidence that the new strain is more deadly, nor that it will be harder to vaccinate against.
Epidemiologist Michael Baker said he expected someone travelling from the UK would bring the new variant to New Zealand.
But it would only be a problem if it got through the border and started a community outbreak, Baker told RNZ yesterday.
The Ministry of Health said it was confident New Zealand’s current use of PPE, testing strategy and 14-day managed isolation for all arrivals was appropriate, while continuing to review those tools in light of emerging evidence.
Baker warned that every time an infected person went into managed isolation and quarantine after arriving from overseas, it increased the risk of mistakes that could lead to an outbreak.
He said a simple measure to increase protection for New Zealand would be to add an extra step. Travellers could need a period of managed isolation before leaving the UK, along with a negative Covid-19 test.
Baker said changes to the virus were not surprising, because there was evolutionary pressure on it. It is constantly changing in small ways. ‘‘It’s always got lots of variants floating around and if one is more infectious than others, it will create more viruses in the next generation and so on, so that strain becomes more dominant.’’
University of Auckland infectious diseases researcher Associate Professor Siouxsie Wiles said data indicated the Sars-CoV-2
virus was mutating quite slowly.
The UK was doing an incredible job sequencing the virus genome, and as a result was skewing the global database of strains, Wiles wrote in The Spinoff. So while a strain might be identified in the UK, that didn’t mean it wasn’t infecting people in other countries, just that the other countries where the lineage might be weren’t doing as much sequencing.
The first genomes of the new variant sequenced in the UK were collected on September 20, Wiles said. Data from a Covid-19 testing lab showed the numbers of people infected with the new variant were pretty steady from October until late November, then started to take off.
She said that under the system for Covid-19 restrictions used in the UK, tier 3 – the most restrictive level until the weekend – allowed churches, gyms, shops, schools and universities to stay open, although cinemas were closed.
She said the new fourth tier was more of a ‘‘tweak’’, with churches, schools and universities still open, and people able to meet one other person from another household if they did so outdoors.
It was likely that high levels of community transmission were causing lineages such as the new variant to emerge.
Researchers thought the new variant evolved in someone with a suppressed immune system, who was chronically infected and shed the virus for months.
‘‘And while chronic infections seem to be very rare, the worse the pandemic gets, the more likely it is that someone somewhere will become chronically infected,’’ Wiles said. ‘‘And the more opportunities there will be for new lineages of Sars-CoV-2 to emerge.’’
Researchers thought the new variant evolved in someone with a suppressed immune system, who was chronically infected and shed the virus for months.