Wastewater data shows early signs of 'resurgence' of COVID-19 viral load in Ontario, expert says

Wastewater surveillance data suggests that there are "early signs of a resurgence" of COVID-19 viral load across Ontario, says a member of the province's COVID-19 science advisory table. 

Dr. Peter Juni, scientific director of the science advisory table, says that means it's vital for residents to get third doses of a COVID-19 vaccine. Juni is also a professor of medicine and epidemiology at the University of Toronto. 

He said wastewater analysis shows that Ontario has reached the bottom of the trough, or valley, in terms of COVID-19 infections but there is a slight upward trend in the concentration of viral prevalence in wastewater across the province.

"What we are seeing basically is the early signs of a resurgence," Juni told CBC Toronto on Saturday.

"For quite some time, this happened outside of the GTA already for a little while. But now we're also seeing that the sleeping giant has woken up and that we start to see a bit of an upward trend also in the GTA," he said.

Juni said the upward trend is expected because of gradual reopening and the data is no reason for alarm but it is important for people to get their third doses. He said experts do not know by how much viral load will rise and he said the increase is not a function of waning immunity to the virus.

The risk of ending up in an hospital or an intensive care unit is reduced fivefold by a third dose, he noted. 

He said, however, there has been a "tremendous slowdown" in the rollout of third doses.

"Right now, for all of those out there who have had only two doses of a vaccine or less, please get vaccinated because you will contribute to the wall of immunity that we are building up through either vaccination or infection. And we need that if we continue to do the reopening," he said.

Ontario has had about three to four million COVID-19 infections due to the Omicron variant since the beginning of December, while roughly seven million people have received their first dose of a COVID-19 vaccine, he said.

"This will very unlikely result in the same challenges that we have had before," Juni said.

"The point really is we're opening relatively swiftly now and there's something we can do to continue to balance the situation out. And this is really just to get vaccinated. That's the part which I'm a bit worried about. There's a little bit of complacency out there now. People don't push for their third dose, and that's a mistake." 

His comments come as the City of Toronto, with its community partners, runs 19 COVID-19 vaccination clinics in shopping and community centres this weekend as part of its ongoing "Shop and Vax" campaign.

Its efforts are part of what it calls a "hyper-local, equity-focused strategy" to improve vaccination rates in select neighbourhoods and communities.