Do vaccines prevent transmission? Should physical distancing be increased? Your COVID-19 questions answered
2 experts answer Checkup callers' questions on vaccines and variants
With the spread of coronavirus variants of concern outpacing vaccination campaigns in parts of the country, many Canadians are wondering what's next.
Nearly 7,000 new COVID-19 cases were reported in Canada on Sunday. And while the total number of cases has declined over the past week, some regions are seeing them rise, according to numbers compiled by CBC.
Nova Scotia, which has consistently reported low daily case counts, broke a provincial record over the weekend with 63 new cases on Sunday.
Meanwhile, a spreading "double-mutant" variant in India has led to the world's worst surge in COVID-19 cases, as hospitals in the country face a shortage of basic medical supplies, including oxygen. That variant has already been identified in several provinces.
"There is a new variant called B1617 which has this unfortunate name of double mutation," said Dr. Prabhat Jha, a global health professor at University of Toronto.
"It basically means there's two mutations on the spike protein, which is what the virus uses to enter a cell. It makes it more infectious, and therefore the case counts [in India] have gone up astronomically."
Jha, along with University of Manitoba virologist Jason Kindrachuk, answered questions from Cross Country Checkup callers on Sunday as part of the show's regular Ask Me Anything series.
Do vaccines stop COVID-19 transmission?
Calling from Grand Falls, N.B., Frank Johnston asked whether vaccines prevent the spread of COVID-19.
Jha said a growing body of evidence suggests they do, and the vaccines are key to developing herd immunity.
"The emerging real-world evidence does suggest that most of the vaccines that we're using in Canada do have an impact on transmission, which is welcome," he said.
Johnston also asked if people who are vaccinated need to continue physical distancing and other protective measures.
In settings where not everyone is vaccinated, Jha said that people should continue with public health guidance, like distancing and wearing masks.
But pointing to recommendations from the U.S. Centers for Disease Control and Prevention (CDC), he said, "We've got to move along."
"The U.S. CDC has moved to what I think is a sensible suggestion," Jha said.
Interim guidance from that health agency says that people who are fully vaccinated can visit the home of others who are fully vaccinated without wearing a mask. The guidance also says fully vaccinated people can also visit one household of unvaccinated people inside a home, without masking up, provided they are not at risk of severe disease.
Canadian health agencies have yet to provide guidance for people who have been fully vaccinated.
Do we need to distance more because of more contagious variants?
James Cohut in Thompson Valley, B.C., asked if more contagious variants of concern mean that physical distancing guidelines need to be updated.
"If variants can be, let's say, 50 per cent more contagious … does this mean our social distancing parameters should change from two metres to three metres, which would be 50 per cent more?" he asked.
Kindrachuk said that it's important to keep in mind that variants have a "better key to fit into the lock to get into our cells."
"What that basically means is that if we put it into a position to infect us, it will," he said.
But physical distancing guidelines were never intended to suggest the virus can't spread beyond two metres, Kindrachuk said. The goal was instead to encourage keeping distance from others.
"The more pertinent question is, 'Are we doing the things properly, as far as not being in close settings for extended periods of time? Are we wearing masks properly? Are we ensuring that we are still using proper hygiene?" he said.
"Viruses, unfortunately, don't always follow the general laws of transmission, as we would like to see them do. They often will change in different situations, and I think we certainly need to be cognizant of that."
Written by Jason Vermes. Ask Me Anything with Dr. Prabhat Jha and Jason Kindrachuk produced by Steve Howard.