TORONTO -- Ontarians are being warned that their behaviour over the next few weeks is critical in determining the quality of their summer as COVID-19 cases start to increase and variants pose a significant risk, according to new modelling data.

Experts with the province released new modelling data on Thursday, revealing that COVID-19 variants are continuing to spread. They warned that Ontario's ability to control the spread would determine the fate of another COVID-19 wave.

“Our behavior over the next few weeks is critical in determining the quality of our summer,” Dr. Adalsteinn Brown, the co-chair of Ontario’s COVID-19 science advisory table, said during the modelling update. “Our ability to control the rate of spread will determine whether we return to normal, or we face a third wave.”

“We’ve learned over this year that preventing the rise of cases is easier than flattening the curve.”

The provincial data released on Thursday showed that cases of COVID-19 are increasing in most public health units and experts say the increase is connected to the more-contagious variants.

“You can see that at the same time as the early variants decline, the new variants are increasing substantially,” Brown told reporters.

“[There are now] two pandemics playing out, one with the early variants under control and one with new variants not under control.”

In a worst-case scenario, the modelling found that by April, the province would see variant case numbers hitting the 8,000 mark. In the best-case scenario, the province could expect fewer than 2,000 cases of the variant per day by April.

The scenario between the worst and best would see daily variant case numbers just below the 6,000 mark. Brown said the situation would “heavily” depend on the province’s approach to dealing with the spread of the variants and vaccination efforts.

“If you see strong public health measures in place, you'd expect to see models trend towards best cases,” Brown said. “If you see weak public health measures in place, you’d expect to see situations trend towards a worst case.”

Hospital and ICU admissions no longer decreasing

The modelling also showed that the number of hospital and admissions to intensive case units for COVID-19 are no longer decreasing and are now levelling off.

Brown said that while ICU admission have decreased dramatically, the occupancy rate remains a challenge. He said that it’s because some of the patients in the unit are very sick and need to stay in hospital for lengthy times.

He said the increasing spread of the COVID-19 variants could make matters worse inside hospitals and ICUs across the province.

In a worst-case situation, the province could see more than 600 people in ICUs. In the best-case scenario, just under 400 people could be in ICUs.

Among the challenges hospitals face is a significant surgery backlog, which has now grown to over 227,000 cases and could get worse as more pressure is placed on the healthcare system.

“We are working hard across hospitals in Ontario to make sure that the most severely ill people get the care that they need,” Brown said. “These are not what we might consider unnecessary or frivolous surgeries, these are surgeries for care that people need

Vaccination in long-term care has ‘paid off,’ experts say

Brown said he is happy to report that staff and resident cases in long-term care homes are continuing to decrease and deaths are flattening. He said no new deaths have been reported in Ontario over the last five days.

“We've had clear success with vaccination in long-term care homes. Deaths and cases are at a very low level now in these homes,” he said. “There’s emerging evidence that vaccinations not only reduces the risk of death and hospitalization, it also reduces the risk of catching and passing on the disease.”

Brown said that new variants are reacting to public health measures in the way as the earlier strain. He said following public health measures and increasing vaccinations across the province are key to preventing a third wave of the pandemic.

“We will really make sure that we control this pandemic and bring us towards the promise that everyone wants of a much better summer, much better even perhaps than last year,” he said.