Ontarians 18 or older will be eligible for vaccine booster shots as of Jan. 4

The Ontario government is introducing stronger proof-of-vaccination measureswhile urging people to keep their holiday gatherings small, safe and fully vaccinated.

"We do not want this holiday season to become a superspreading event," said Dr. Kieran Moore, Ontario's chief medical officer of health, during a Friday afternoon press conference.

Minister of Health Christine Elliott warnedat the same conference that the months ahead would be "very challenging"hours after the province reported 1,453 new daily cases of COVID-19.

As the omicron variant looks to become "a dominant strain very soon," Moore said the province is opening up booster shots to Ontarians age 18 or older starting Jan. 4, 2022.

It is also dropping its tentative plan to end the provincial vaccine-passport program in mid-January and will require all proof-of-vaccination certificates to include QR codes as of Jan. 4, 2022.

The QR codes, rolled out a month after an initial PDF version of the certificate, are said to be much harder to fake. The province has come under fire in recent weeks for continuing to accept the easily Photoshopped PDFs.

QR code also needed for medical exemptions

The province is also moving ahead with a plan to have medical exemptions for COVID-19 shots require a certificate with a QR code. A doctor's note will no longer be acceptable proof for exemptions for businesses operating under the provincial system as of Jan. 10, 2022.

Similarly, the government says any children between the age of 12 and 17 participating in sports or other recreation activities will be required to show proof of vaccination as of Dec. 20.

Cases up 41% over last week

Friday's case count marks a 41 per cent increase over last Friday and is the most new infections loggedon a single day since May 23as the third wave of the pandemic was slowly waning.

The seven-day average of daily cases has risen to 1,115, and is currently on pace to double roughly every three weeks.

Public Health Ontario today reported a 4.4 per cent positivity rate on 39,941 tests, by far the highest level of the fourth wave and also the highest one-day rate since May 26.

Still, the burden of COVID-19 on intensive care units has stayed relatively stable. As of Thursday, there were 151 COVID patients in critical care, down from 155 the day before and 17 fewer than the fourth-wave peak of 168 reachedearlier this week.

School outbreaks at their highest

The province reported another pandemic high for school-related outbreaks, with 286, including 257 in elementary schools.

A senior government source told CBC News there are no plansto shut down the province's schools before the winter holidays one week from tomorrow.

During the third wave of the pandemic in the spring, school-linked outbreaks peaked at 264 on April 14, two days after the province announced it would close schools in a bid to contain transmission of the virus.

In recent weeks, schools have been the setting for the bulk of COVID-19outbreaks in Ontario. In this context, an outbreak is defined as two or more lab-confirmed cases in students, staff or visitors where at least one of the infections has an epidemiological link, meaning the case was transmitted within the school, not in the wider community.

As of Thursday, about 26.4 per cent of five to 11-year-olds in the province had a first dose of vaccine.

Meanwhile, the provincial Ministry of Health also reported the deaths of 11 morepeople with the illness on Friday, bringing the official toll to 10,065.