Ontario has likely entered a new wave of the pandemic driven by the more infectious BA.5 subvariant, the province’s science advisory table says.

The table made the declaration in a series of messages posted to Twitter on Wednesday afternoon, citing “exponential growth” in case counts in about 80 per cent of public health units as well as rising hospitalization numbers and test positivity rates.

The scientists also said that the wastewater signal in most regions is now rising, pointing to higher levels of viral activity overall.

“Current evidence does not suggest BA.5 is more severe or that it will lead to a rise in hospitalizations as large as previous waves. However, any surge comes at a time when hospitals are already dealing with staff shortages and record wait times – this impacts all of us,” the table said. “And if BA.5 spreads widely, we may see a rise in deaths among higher risk groups such as the elderly as was observed during the previous waves.”

The warning from the science table comes as a number of countries experience a rapid rise in transmission due to the BA.5 subvariant.

In Ontario, where the subvariant is now dominant, most public health indicators are also starting to head in the wrong direction after months of gradual improvement.

The most recent data released by the Ministry of Health on June 30 showed a week-over-week increase in COVID-19 hospitalizations for the first time since May.

The positivity rate on PCR tests was also up, with the seven-day average going from 7.64 on June 23 to 9.82 on June 30.

Meanwhile, the public health measures that existed during previous waves of the pandemic are now all gone, including a mask mandate for high-risk settings that was terminated last month.

Science Table Head Dr. Fahad Razak told CP24 that he doesn’t believe a “mask mandate by itself would have prevented the rise that we're seeing” now but he did say that he sees masks as a “very low-burden way of reducing viral spread and allowing us to do a lot of the other things we value.”

“Masks to me are part of the solution and this is clearly a time where there's an enhanced value in using that mask in an indoor setting,” he said.

 

NO EVIDENCE TO SUGGEST BA.5 IS MORE SEVERE

The science table said that there is “no evidence to suggest BA.5 is more severe or that it will lead to a rise in hospitalizations as large as previous waves.”

But it did say that “we may see a rise in deaths among higher risk groups such as the elderly as was observed during the previous waves.”

“This is a global phenomenon. All countries in the western hemisphere are experiencing this,” Ontario’s Chief Medical Officer of Health Dr. Kieran Moore told CP24 on Wednesday. “As our borders are opening, as travel returns it is natural that this virus will circulate globally. But Ontario to date is doing very well at minimizing its impact on the health-care system.”

The science table says that Ontarians should take a number of precautions as a result of the rise in transmission, including “going back to wearing a mask again in crowded indoor public spaces” and ventilating indoor spaces as much as possible by opening windows and doors.

Moore also said that Ontarians should be making sure they are up to date with their vaccinations.

“I would like to just point out that there are 5 million Ontarians who still haven't taken advantage of our first booster dose and one million of them are over 50 and in our opinion at risk for severe outcomes from COVID-19,” he said. “So please stay up to date with your vaccinations. I appeal to those 5 million Ontarians that haven't taken advantage of the first booster to please come forward.”