COVID-19 Treatment

Health care providers can find information on the use of select drug therapies for the management of adult patients with confirmed COVID-19 across all disease severities (mild, moderate, severe and critically ill).

These documents are endorsed by Ontario Health’s Infectious Diseases Advisory Committee.

Mild to Moderate COVID-19

Clinical Guidance

The following documents are intended to provide guidance on the appropriate prescribing of antiviral therapy (nirmatrelvir/ritonavir and remdesivir) for adults with mild to moderate COVID-19.

In April 2024, this guidance was updated to take into account recently circulating strains of SARS-CoV-2 as well as pre-existing immunity from prior infection and/or vaccination in Ontario. Highlights include updates to the COVID-19 severity classification and risk factors associated with more severe COVID-19 outcomes, along with an overview of the real-world evidence for antiviral therapies.

Antiviral therapy for COVID-19 such as Paxlovid (nirmatrelvir/ritonavir) and Veklury (remdesivir) can prevent serious illness in certain high-risk individuals if taken within the first few days after symptoms start. Individuals should have mild or moderate symptoms and a positive test for SARS-CoV-2 before receiving antiviral therapy.

Antiviral therapy is recommended for individuals who are:

  • 65 years of age or older (regardless of vaccine status and any other risk factors)
  • 18 years of age or older and immunocompromised (regardless of vaccine status or prior COVID-19 infections)

A health care provider may also consider prescribing antiviral therapy to adults who are at an increased risk of severe COVID-19 outcomes because they have risk factors such as certain medical conditions or are unvaccinated.

A patient’s risk of progressing to severe COVID-19 exists on a continuum and is influenced by many factors such as age, vaccination status, and immunocompromised status, together with the number, type, and degree of control of medical conditions. The list of risk factors included in the guidance document is intended to assist prescribers in making individualized treatment decisions based on their assessment of patient risk.


Severe to Critical COVID-19

Clinical Guidance

Additional guidance on the treatment of severe to critical COVID-19 will be added in the future.

Last Updated: May 17, 2024