A majority of Quebecers have hybrid immunity to COVID-19, but new variants this fall could cause a surge in cases and hospitalizations, according to the province's public health institute (INSPQ).

The institute said variants could have a greater impact than Omicron if they mutate beyond what hybrid immunity can mitigate.

Hypothetical scenarios for Greater Montreal were examined by experts from the INSPQ and Laval University.

They say a COVID surge between now and winter 2023 could be "limited' if a new variant is nevertheless countered by hybrid immunity.

However, if a variant that escapes this immunity -- "with a similar level of escape as Omicron compared to Delta" -- it could cause a surge surpassing that of the Omicron wave, the INSPQ said Thursday in a statement.

According to the institute, "a significant number of hospitalizations could result, even if the variant is not more severe than Omicron and the protection offered by hybrid immunity is high against hospitalizations."

This report was first published in French by The Canadian Press on Aug. 11, 2022.