OTTAWA — Health Canada on Monday approved Pfizer’s antiviral treatment for COVID-19, which could help ease pressure on the healthcare system by preventing high-risk patients from ending up in the hospital.
Due to limited Paxlovid supplies, Canada’s Health Agency is asking provinces and territories to prioritize treating people at greatest risk of serious illness, including severely immunocompromised patients and some unvaccinated people over 60.
“Canadians should be very pleased today to hear that oral antiviral drugs are becoming available in Canada,” said Dr. Chief Public Health Officer Theresa Tam at a virtual briefing Monday.
Health Canada’s approval means Paxlovid can be prescribed to adults who test positive for COVID-19 on a molecular or rapid test, who have mild or moderate symptoms and are at high risk of developing serious illness.
Clinical trials showed that treatment, which helps prevent the SARS-CoV-2 virus from multiplying in an infected patient, was nearly 90 percent effective in reducing hospitalizations and deaths in high-risk patients when given within three days after infection, and 85 percent cents if given within five days.
The drug requires three pills at a time, twice a day, for five days. It’s the first oral COVID-19 treatment that can be taken at home to be approved in Canada, but Tam admitted there might be some logistical challenges getting the drug to the right people quickly enough.
“It’s challenging, there’s no doubt about that,” Tam said. “First, you need to identify that you may have symptoms and then seek medical attention quickly.”
dr Zain Chagla, an infectious disease specialist at McMaster University, said the supply shortages mean Paxlovid’s effects may be slow, but overall it should help reduce the number of people who get seriously ill.
“There’s certainly a lot of hope here,” he said.
Canada has contracted one million treatments this year, but supply issues are limiting its use wherever it has been approved.
Procurement Minister Filomena Tassi said more than 30,000 treatments are already in Canada and will be distributed to provinces on a per capita basis this week.
She said another 120,000 courses of the treatment will be shipped before the end of March. She didn’t say when the rest of the one million doses Canada bought will come, nor did she want to disclose the cost, citing contract confidentiality.
Neither does Pfizer Canada, although Pfizer said in the fall that the United States pays about $530 per treatment cycle.
Chagla said it was difficult to know how many cycles would be enough, but he said everyone helps, especially when there are enough available for immunocompromised people where vaccines don’t work very well.
Tam said that due to supply shortages, the Public Health Agency of Canada is asking provincial and territorial governments to prioritize patients at highest risk for the drugs.
Severely immunocompromised patients, such as transplant recipients, are high on the list of priorities. They are followed by unvaccinated people over 80 and then unvaccinated people over 60 living in long-term care, remote or rural areas, or First Nations.
Tam said prioritizing unvaccinated people is scientific and rational as they are at higher risk of serious consequences.
“I think that as a healthcare provider, you don’t choose which patients come into the hospital to be treated,” she said.
Chagla said that from a health resource perspective, keeping unvaccinated patients out of the hospital is a huge help for everyone, and for most patients, getting vaccinated means they are not at high risk of developing serious diseases.
“Getting two or three doses of vaccine is probably like having Paxlovid in your system all the time (regarding) to prevent people from getting seriously ill,” he said.
The U.S. Food and Drug Administration has approved Paxlovid for patients as young as 12, but Health Canada said the company hasn’t presented safety or efficacy data in this age group, so it’s not currently approved for people under 18 can .
Health Canada also says the treatment must not be used in patients already hospitalized with severe or critical COVID-19, or as a preventive treatment before or after anyone has been exposed to the virus. It must also not be given to a patient for more than five days.
It warns that there are some potentially serious drug interactions between Paxlovid and other drugs prescribed for conditions such as prostate cancer and heart problems and narcotics including fentanyl.
This report from The Canadian Press was first published on January 17, 2022.
Mia Rabson, The Canadian Press
Note to readers: This is a corrected story. An earlier version said that two tablets were taken twice a day for five days.