TORONTO -- With children going back to school across the country, some infectious disease experts say it's time to rethink our social bubbles in order to protect our most vulnerable populations from contracting COVID-19.

That could mean veering back to virtual visits for grandma and grandpa, or at the very least, reintroducing distancing and mask-wearing when seeing them.

Dr. Barry Pakes, a public health physician and professor at the University of Toronto, says there is plenty to consider in deciding whether to kick grandparents out of your bubble, including how old your kids are, how big their classes are, and whether their schools are implementing remote or in-person learning.

"It's going to be hard for parents to factor in all those elements and make a decision, but I think the simplest thing is just rethinking how our bubbles are looking and potentially reintroducing more masking and distancing around people who are vulnerable," Pakes said.

"Certainly distancing completely from grandparents is going to be the safest option, but that isn't going to be in the best interest of everybody's mental health."

Most provinces cap social circles or bubbles at 10 people, though some, including Alberta, allow 15. Bubbles are safe in theory if everyone in one bubble agrees to only interact with people in that same circle.

But with children going back to school and interacting with teachers and other students every day, our bubbles are suddenly expanding "almost infinitely," Pakes said.

And while he doesn't think we need to throw bubbles out the window completely, we do need to reassess them.

Dr. Ilan Schwartz, an infectious disease expert at the University of Alberta, agrees, saying the "idea of a bubble still has validity.

"But as that bubble expands, it becomes weaker and weaker. The more individuals in that bubble, the more likely there's going to be a breach. ... And soon the bubble becomes so porous that it really has no protective value at all."

Schwartz says it's a "delicate balance" determining when a bubble has become too expansive, but limiting class size in schools can help it from getting out of control.

"The smaller that bubble, the more hope there is for it to retain its integrity," he said.

Individual families will have to determine the level of risk they're comfortable with when debating excluding grandparents from their social circles, Schwartz said.

The more people students interact with on a daily basis, the higher the risk of being exposed to the novel coronavirus. And while most young people won't experience bad COVID outcomes, older people are at a greater risk for severe illness.

The Centers for Disease Control and Prevention website says risk increases with age, so people in their 60s or 70s are more likely to experience severe outcomes than those in their 40s or 50s. The greatest risk for severe illness from COVID-19 is among those aged 85 or older.

Schwartz says waiting until the pandemic is over before grandparents can see their grandchildren again isn't practical.

"The virus isn't going away any time soon," he said. "But as long as people are educated about the activities that put them at risk and the ways to mitigate that, I think we can make informed decisions."

For instance, it's best to avoid hugging or touching, especially without a mask, Schwartz said, and outdoor meet-ups are still preferred to indoor events.

As the weather gets cooler and social activities are forced indoors, however, Schwartz says well-ventilated areas -- while distance is maintained or masks are being worn -- can still be safe.

Pakes says social bubbles offer just one layer or protection, and things like hand-washing, mask-wearing and physical distancing shouldn't be ignored, especially when it comes to interacting with more vulnerable segments of population.

He says now is a good time to gradually reintroduce those measures for grandparents already in our bubbles, rather than shutting them off completely as soon as children return to class.

"You don't want kids to link going to school with not being able to see their grandparents," he said. "But if families can (shift) these interactions, consider doing things outside while it's still somewhat warm out, we can mimic normal as much as possible."

Dr. Zahid Butt, an assistant professor and infectious disease specialist at the University of Waterloo, says now is a critical time to take extra precautions when it comes to older populations, however.

COVID-19 cases are on the rise in parts of Canada, with 3,955 people testing positive last week -- a significant jump from the 3,044 positive tests in the week prior.

And since we may not know the potential transmission impact of reopening school for at least a month, Butt says it's best to avoid interacting with grandparents altogether until then.

Bringing back socializing methods used early in the pandemic, like Facetiming or conversing from the front yard while grandma stays on the porch, could be temporary solutions.

"That would be a better approach at this time because we're not really sure what will happen when all of the children return to school," he said. "So at least for the initial weeks or maybe months, I think it's better to hold off the (in-person) interactions."

This report by The Canadian Press was first published Sept. 10, 2020.