Ontario continues to see a spike in new COVID-19 cases with more than 1,400 infections confirmed over the past 24 hours as the province’s top doctor says the Omicron COVID-19 variant may become dominant "soon."

Provincial health officials logged 1,453 new cases today, up from 1,290 on Thursday and 1,031 one week ago. It is the highest single-day total since May 23.

The seven-day rolling average of new infections has jumped to 1,115, up from 866 last Friday.

At a news conference Friday afternoon, Dr. Kieran Moore, Ontario's chief medical officer of health, said as of Thursday, 10 per cent of the samples sequenced by Public Health Ontario tested positive for the Omicron variant.

"I am concerned about the rise in Omicron across Ontario," Moore said.

"It's anticipated that we'll have a significant rise in the coming weeks and in the next month. And that it may become a dominant strain very soon."

Moore added that Omicron could replace Delta as the dominant variant by January. That's why he is urging Ontarians to be cautious during the holiday season.

"We need to really reflect on how we can best protect each other over the winter holidays. I know many already had plans for social gatherings. We're asking to be prudent to be cautious, to be moderate," Moore said

"We do not want this holiday season to become a super spreading event."

Of the new cases confirmed today, 613 involve those who are unvaccinated, 26 involve individuals who are partially immunized, 718 are in people who have received at least two doses of a COVID-19 vaccine, and 96 involve those with unknown vaccination status.

Nearly 81 per cent of all Ontario residents, including those under five who are not yet eligible to receive a COVID-19 vaccine, have been given at least one dose and 76 per cent have received two doses. Unvaccinated individuals currently represent about 19 per cent of Ontario's population but account for about 42 per cent of all new cases today. Of those who are eligible to receive a COVID-19 vaccine, 85.5 per cent have received at least one dose and 80 per cent have received at least two shots.

With 39,941 tests processed yesterday, officials are reporting a provincewide positivity rate of 4.4 per cent, the highest that number has been in more than six months.

The number of COVID-19 patients in intensive care is now 151, up slightly from 146 last week. According to the Ministry of Health, only 29 of those patients are fully vaccinated.

The province says 11 more virus-related deaths were added to Ontario's COVID-19 death toll today, which now stands at 10,065.

The public health units with the highest number of new cases today include Toronto (195), Ottawa (109), Kingston, Frontenac and Lennox, & Addington (95), York Region (91), Peel Region (89), Windsor (89), Durham Region (76), Simcoe Muskoka (73), Halton Region (68), Hamilton (54), and London-Middlesex (52).

The number of known, active COVID-19 cases in Ontario is now 9,193, up from 7,217 seven days ago.

With rising infections, there have been calls for the province to quickly roll out third doses to as many adults in the province as possible.

Starting next week, all Ontario residents over the age of 50 will be eligible to receive their third shot, provided it has been six months since they were given their second.

On Friday afternoon, the province announced that it is expanding booster eligibility for Ontarians aged 18 and up starting on Jan. 4.

So far, just under one million third doses have been administered in Ontario.

Dr. Andrew Boozary, the executive director of social medicine and population health at the University Health Network, tweeted Friday that Ontario should no longer consider two doses as fully vaccinated. Dr. Issac Bogoch, an infectious diseases specialist with Toronto General Hospital, said third doses are now "even more important" with the arrival of the Omicron variant in Canada.

"I think it is fair to say that we are seeing a real rise in cases and it is also fair to say that Omicron is here and Omicron is spreading... We know that the vaccines, while extraordinarily helpful and are expected to continue to help with Omicron, won't be as helpful as they are against Delta so we might see even more spread," he told CP24 on Friday morning, adding that vaccines still help prevent severe illness.

"I think you have to take steps to really ensure that you keep this virus under control at the level of the province."