Ontario has announced changes to the proof of vaccination system after a "sudden escalation" of Omicron cases and data suggesting it will be the dominant strain by January.

Effective Jan. 4, Ontario will require people to use their QR code and the Verify Ontario app in settings where proof of vaccination is required, the government announced Friday.

The QR code can be used digitally or by printing a paper copy. 

Effective Dec. 20, proof of vaccination will now be required for youth aged 12 to 17 participating in organized sports at recreational facilities. 

Ontarians are also being "strongly advised" to limit their social gatherings and the number of gatherings they attend over the holiday season. The current gathering limits in most health units is 25 people indoors.

Expanded booster dose eligibility to all Ontarians 18 years of age and older will occur on Jan. 4, 2022, with appointments to be booked approximately six months after receiving a second dose.

Chief Medical Officer of Health Dr. Kieran Moore said Friday that Ontario is now reviewing the definition of fully vaccinated and whether that should mean three doses of the vaccine.

'SUDDEN ESCALATION' OF OMICRON CASES 

Moore said that Ontario is seeing a sharp rise in cases of the Omicron COVID-19 variant, and this strain now represents 10 per cent of all new infections in the province.

"It's truly proving itself to be a highly transmissible strain and more transmissible than Delta," Moore said. "I do think this is absolutely recent activity."

He said projections from Public Health Ontario show that this trend will continue at a rapid pace.

Moore said there could be a "complete strain replacement" in Ontario as early as the beginning of January.

Meanwhile, the Ontario government says it will also launch a holiday COVID-19 testing blitz next week, offering a voluntary rapid test to asymptomatic individual’s free of charge.

"Two million rapid tests will be provided at pop-up testing sites in high-traffic settings such as malls, retail settings, holiday markets and transit hubs," the government said.

Ontario reported 1,453 new cases of COVID-19 on Friday, the highest number in a single day since May.