Pfizer's new antiviral COVID-19 pill has been approved by Health Canada, but its rollout in Ontario will start slowly.

Health Minister Christine Elliott's office said Ontario expects about 10,000 treatment courses from the federal government this month, though exact shipment times haven't been confirmed.

Due to the small supply, spokesperson Alexandra Hilkene said just 15 hospitals across Ontario will have access to the antivirals as soon as they arrive. She did not say which 15 hospitals will get the drug.

Those with the highest risk of severe illness will be prioritized for the drugs, like immunocompromised people, she said.

The antivirals "could help keep thousands of people out of our hospitals," she said. "The arrival of these pills gives us increased confidence as we continue to review key indicators and data to determine when we can begin safely and gradually lifting public health measures, and we look forward to providing additional details in the near future."

The federal government has an agreement with Pfizer for one million doses, though it's not clear when exactly those will be distributed.

Federal Chief Public Health Officer Dr. Theresa Tam said Ottawa is working on a delivery schedule with Pfizer to get doses into Canada as fast as possible.

On Monday, Health Canada approved the prescription-only oral pill, called Paxlovid, for adults aged 18 and up. Pfizer also applied for authorization for the pill's use for kids 12 and up.

The pill can be used to treat mild-to-moderate COVID-19 in adults "who are at high risk for progression to severe COVID-19, including hospitalization or death," per Health Canada.

Health Canada’s Chief Medical Adviser Dr. Supriya Sharma said the treatment could help reduce the number of patients in hospital, but that it is no substitute for vaccination.

The drug lowers the chance of hospitalization by 89 per cent in people displaying positive COVID-19 symptoms compared to those who got the placebo, Pfizer said in its phase 2/3 results in November.

Paxlovid is two pills, packaged together — 150mg of Nirmatrelvir 100mg of Ritonavir. It works by blocking a critical enzyme of the SARS-CoV-2 virus, stopping it from replicating itself within the body.

Side effects can include a loss or altered sense of taste, diarrhea, increased blood pressure, liver problems and muscle aches, according to the U.S. Food and Drug Administration. Paxlovid can also interact with other medications. And it could make drugs that treat HIV less effective in the future, for patients with undiagnosed HIV.

Pfizer antiviral COVID pill will be available at 15 Ontario hospitals to start

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