Ontario has entered a 7th wave of COVID-19, driven by the more infectious BA.5 subvariant of Omicron.

The declaration came Wednesday from members of the province’s COVID-19 science advisory table.

They site “exponential growth” in case counts in about 80 percent of public health units as well as rising hospitalization numbers and test positivity rates.

The scientists also say 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.

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.