Antivirals could be a pandemic game-changer — and they could be in Canada soon

As a pandemic-weary country confronts another wave of COVID-19 cases with a strained health care system, Health Canada is looking at new products that could offer some relief: antivirals.

Two such drugs are making their way through the labyrinthine Health Canada approvals process: Pfizer's Paxlovid and Merck's molnupiravir.

These antiviral treatments, which are prescribed by a doctor and administered in pill form, are designed to help the body fight off the SARS-CoV-2 virus, reduce symptoms from an infection and shorten the period of illness.

While Merck has grappled with questions about the efficacy of its product — molnupiravir is said to reduce hospitalization or death by 30 per cent — Paxlovid earned especially high marks in testing.

After a months-long study, Pfizer reported in November that Paxlovid reduced the risk of hospitalization or death by an impressive 89 per cent compared to a placebo in non-hospitalized high-risk adults with COVID-19.

Health care professionals here are now scrambling to get their hands on this product to help ease the pressure on hospitals and save lives.

While Canada has some of the highest vaccination rates in the world — a development that has dramatically reduced cases of severe illness — infections among the unvaccinated and breakthrough cases in those with two doses are still testing a health care system that is on the ropes after two years of the pandemic.

An effective pill that's easy to self-administer at home could relieve some of that pressure and change the trajectory of the pandemic.

Dr. Zain Chagla is an associate professor at McMaster University and an infectious diseases physician who is leading a pilot program offering monoclonal antibodies at St. Joseph's Healthcare in Hamilton, Ont.

Chagla said therapeutics — especially those like Paxlovid that can be administered outside of a hospital setting — are "absolutely" a "game-changer."

"We know that vaccines have an incredible role to play but we need a backup option," Chagla told CBC News. "Therapeutics give the highest-risk people the chance to stay out of hospital and have a benign recovery like everybody else."

Deployed properly in the most vulnerable populations infected with COVID-19 — the unvaccinated, the immunocompromised, the elderly and people with comorbidities — therapeutics could reduce hospitalizations by as much as 80 per cent, Chagla said.

Fewer hospital admissions would leave more capacity in the health care system — which could put an end to lockdowns, he said.

"A large number of the true COVID hospitalizations are groups you could pick out on paper and say, 'If this person gets COVID, they're going to be at highest risk,'" he said.