Cases of a Covid-19 strain that has plunged the UK into chaos have been detected in small numbers in Australia, but the federal health minister, Greg Hunt, has said there are no plans to follow other countries in halting flights from the UK.
On Sunday the UK prime minister, Boris Johnson, said there was “no evidence” the strain caused more severe illness or higher mortality, but “it does appear to be passed on significantly more easily”. It prompted some European countries, including Ireland, Italy, France, Germany, Belgium and the Netherlands, to ban flights from the UK.
Hunt told reporters on Monday that Australia’s hotel quarantine system, under which international arrivals enter mandatory 14-day monitored quarantine at dedicated hotels, meant Australia would not be doing the same.
“One of the things in Europe is that they have not adopted a similar [hotel quarantine] system,” Hunt said.
Australia’s chief medical officer, Prof Paul Kelly, said the UK strain, known as the N501Y mutation, needed to be put in context.
“There has been thousands of mutations of this particular novel coronavirus,” Kelly said. “There is no definite evidence that this is a significant change. There has been more transmission in recent times in the south-east of the UK and that may be associated with the virus.
“The infectious agent has changed a little, but a lot of people have been moving around in south-east England and have been until the recent lockdown. It is also winter.
“In terms of what that means for people coming from the UK, everyone coming from the UK is going to 14 days of hotel quarantine.”
Assoc Prof Linda Selvey, a public health physician and an infectious diseases epidemiologist at the University of Queensland, said while the quarantine system had not proved 100% fail-safe in stopping transmission, “it is still largely protecting the community”.
“In addition, it is quite likely that the variant has already spread further than the UK, particularly as other countries are not doing the same amount of genomic sequencing as in the UK,” she said.
The New South Wales chief health officer, Dr Kerry Chant, confirmed on Monday that “a couple of UK returned travellers” were found to have the N501Y strain. But she said the current outbreak of concern in NSW, affecting the northern beaches and known as the Avalon cluster, was a different strain to the one wreaking havoc in the UK.
An associate professor at the Kirby Institute at UNSW, Dr Stuart Turville, said Westmead and Prince of Wales hospitals in NSW had sequenced the northern beaches cluster, and found that it was “nothing like the UK variant”.
“The northern beaches one has been observed in US and European samples, but the frequency is low,” Turville said. “Australia is somewhat unique in the pandemic. When the virus does breach our quarantine it is only one seeding event. This was seen in Melbourne. One virus gets out and then expands.”
Victoria’s deputy chief health officer, Prof Allen Cheng, said it was not clear whether the UK variant was truly more infectious. It could appear to be spreading faster for multiple reasons, he said.
“For example, it could be simply the strain that was involved in a super-spreading event, or spreading in a part of the country where restrictions are less strict or less adhered to,” Cheng said. “Higher viral loads could reflect detection earlier in the illness.”
He said that Australian health authorities were “keeping a close eye on things”. Cheng said it was also unclear whether the N501Y mutation would have any impact on vaccine efficacy. The vaccines all target the spike protein of the virus, and Cheng said the mutation did affect the binding site of the spike protein.
“But further studies are required to see if it affects how the immune system recognises the virus after immunisation,” he said. “One thing to look out for is if people who had previously been infected get re-infected with this strain. I haven’t seen any reports of this yet.”
Selvey agreed that while there is some evidence that suggests that the UK variant is more infectious than other strains, “the evidence is still fairly limited”.
“It is worthwhile noting that in the UK, and London in particular, there had been very few restrictions on peoples’ movements in spite of having a high incidence of Covid-19,” she said. “Therefore it is difficult to know whether the virus is more infectious or whether it relates to individuals’ behaviours.”
Given that the UK has already commenced vaccinating healthcare workers with the Pfizer vaccine, and given the high incidence of cases in that country, it may be possible to know within a few months whether or not the vaccine is effective against the variant, Selvey said.
“No doubt public health officials will be watching this very closely. If it turns out that the vaccine is not as effective against the variant as against other strains of the virus, it should be possible to modify the Pfizer vaccine fairly easily, given that it involves the transfer of genetic information known as mRNA.”
The best protection against the variant is the same as against other strains: social distancing, wearing masks in crowded places, and hand hygiene, she said.