The emergence of a more contagious variant of the virus that causes COVID-19 does not require individuals to take new precautions, but it is now more important than ever that they follow existing public-health guidelines, doctors and scientists say.
While new variants of the virus SARS-CoV-2 have recently been detected in South Africa, Nigeria and Britain, the latter country’s version, called B117, has caused particular concern, as scientists estimate it is more transmissible than other mutations of the virus. This new variant has also been identified in people in Ontario, British Columbia, Alberta and Quebec, and the Canadian government has suspended flights from Britain until Jan. 6. Meanwhile in Britain, there are growing calls to impose another national lockdown and shut down schools and universities.
In a study, yet to be peer-reviewed, British scientists estimated B117 is 56 per cent more transmissible than pre-existing variants of the virus. Although they found no clear evidence that it affects the severity of illness, they warned that the increased transmissibility would likely lead to a surge in hospital admissions and deaths. They suggested strict lockdown measures may not be sufficient, unless primary schools, secondary schools and universities are closed.
“I would say that the current social distancing guidelines are more important than ever given this new variant,” lead author Nicholas Davies of the London School of Hygiene and Tropical Medicine said in an e-mail. “People should be cautious, follow the guidelines, and self-isolate if they suspect they may have been infected.”
But the estimated increased transmissibility of the new variant does not mean existing public-health advice for personal protection – such as wearing masks when you may come in close contact with others, keeping two metres away from people outside your household and maintaining hand hygiene – will be less effective, experts say.
Rather than changing the current guidelines, Leighanne Parkes, an infectious-disease specialist and microbiologist at the Jewish General Hospital in Montreal, said she would be happy to see people actually follow them.
“People take little shortcuts from time to time and give themselves little cheat days. And I think that’s where the danger lies, when we let down our guard and we fail to remain vigilant,” she said.
Dr. Parkes said family members have contacted her over the holidays, expressing worry that this new variant adds another twist to an already calamitous year. But, she explained, there have been numerous variants since the very emergence of SARS-CoV-2. And some, such as a variant called D614G, have become predominant worldwide.
Dr. Parkes said it is important to note that large task forces and working groups at the global level are trying to determine the significance of the changes to the virus in the new variant.
Technically, she said, it involves a mutation within a part of the binding loop, which is part of the virus that sticks to our ACE-2 receptors, the part of the cell to which the virus binds to gain entry. The concern is that since this mutation affects an important part of the virus and how it attaches to cells, it raises questions such as whether it has increased tissue-specificity – that is, it binds to cells in the nose and upper respiratory tract where it can be spread through droplets with greater ease, whether smaller quantities of the virus can lead to infection, and whether it changes the way people respond to it.
While there are experts working to rapidly answer these questions, “I think as of now, we just don’t know. These are all kind of black holes in our knowledge,” she said.
In an e-mailed statement, Health Canada said the government is closely monitoring the variant and is working with international groups, including the World Health Organization.
“While early data suggest that the United Kingdom variant may be more transmissible, to date there is no evidence that the mutations have any impact on symptom severity, antibody response or vaccine efficacy,” it said, but noted evidence is limited at this time.
But no matter the variant, SARS-CoV-2 is a virus that transmits very easily, and it is well known that people can spread it when they are minimally symptomatic or asymptomatic, Dr. Parkes said.
“As always, given the high potential for asymptomatic transmission of SARS-CoV-2, the most prudent course of action for individuals is to act as though they might have the virus,” Dr. Davies at the London school added in his e-mail.
While the mutations of the new variant may change how efficiently people contract the virus, they do not change the mechanism by which it spreads, said Emanuel Goldman, a virologist and professor of microbiology, biochemistry and molecular genetics at Rutgers New Jersey Medical School.
The main route of transmission is still through what we breathe, so wearing a mask in public places, particularly indoors, is still the first line of defence, Dr. Goldman said. There is no need to go back to wiping down groceries as many did at the beginning of the pandemic, since transmission of the virus from surfaces is almost non-existent, he said.
“The virus may be more transmissible, but it’s not less fragile,” he said, explaining it degrades rapidly when exposed to the environment.
When it comes to behaviours that stop the virus, “everything should stay the same. What works for the parent will work for the variants,” Dr. Goldman said.
Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.