OTTAWA -- The federal government has signed deals with Pfizer and Merck to purchase their antiviral medications, pending Health Canada approval of the products.

Public Services and Procurement Minister Filomena Tassi said Ottawa has placed an initial order for one million of Pfizer’s antiviral pills, and 500,000 of Merck’s pills, with an option for 500,000 more.

Tassi made the announcement during a press conference on Friday.

“As soon as these drugs are authorized for use, the government will work on getting them to provinces and territories as quickly as possible so that health-care providers can help Canadians who need it most,” said Tassi.

“I will keep working to ensure that we have the supplies Canada needs to finish the fight against COVID-19.”

On Wednesday, Pfizer initiated a rolling submission to Health Canada of its drug PAXLOVID, intended for use in mild to moderate COVID-19 cases in adults at increased risk of hospitalization or death.

Its trial enrolled non-hospitalized adults aged 18 years and older.

The drug maker said in a press release that the pill is designed to block the activity of an enzyme in SARS-CoV-2 that is essential for the virus to replicate itself, and also help to slow the breakdown of the pill’s ingredients in order to help combat the virus for longer. Part of the pill uses ritonavir, an existing drug that has been used in combination with other antiviral medications before.

Merck submitted its request for approval of its twice-daily drug molnupiravir in August. The antiviral agent is intended for use in those 18 years old and above and is to be taken five days after the onset of COVID-19 symptoms.

Minister Tassi on procuring antiviral drugs

Merck’s study tracked 775 adults with mild-to-moderate COVID-19 who were considered to be at higher risk for severe disease because of health problems such as obesity, diabetes or heart disease. Among patients taking molnupiravir, 7.3 per cent were either hospitalized or died at the end of 30 days, compared with 14.1 per cent of those who received the placebo.

Health Canada has already approved four COVID-19 treatments. They include: remdesivir, bamlanivimab, casirivimab and imdevimab combination, and sotrovimab.

Tassi said antivirals should be viewed as a “complement” to vaccines.

“It’s another tool that we have available in order to fight this fight against COVID-19. It in no way takes away from the importance to ensure that we get the vaccinations but it’s an important tool because it prevents, for those that do get infected by COVID-19, from having effects and impacts,” said the minister.

Duclos further specified that therapeutics are the government’s fourth tool in the toolbox, after personal protective equipment, testing, and vaccines.

He said that the these treatments aren’t just beneficial at the patient level, but also to prevent overwhelmed hospitals.

Health Canada's chief medical adviser Dr. Supriya Sharma has said an approval will only be granted when all evidence has been reviewed.

With a file from Brooklyn Neustaeter, Avis Favaro, and Elizabeth St.Philip