About COVID-19

Coronaviruses are a large family of viruses. COVID-19 is a new disease caused by a strain of coronavirus that had not been previously identified in humans.

How it's transmitted

Human coronaviruses cause infections of the nose, throat and lungs. They are most commonly spread from an infected person through:

  • respiratory droplets that are spread when you cough or sneeze
  • close personal contact, such as touching or shaking hands
  • touching something with the virus on it, then touching your mouth, nose or eyes before washing your hands


Those who are infected with COVID-19 may have little to no symptoms. You may not know you have symptoms of COVID-19 because they are similar to a cold or flu.

Symptoms may take up to 10 days to appear after exposure to COVID-19.

Symptoms have included:

  • Fever
  • A new cough, or worsening chronic cough
  • Sore throat
  • Runny nose
  • Headache
  • A new onset of fatigue
  • Diarrhea
  • Loss of sense of taste
  • Loss of sense of smell
  • In children, purple markings on the fingers and toes
  • Difficulty breathing

In severe cases, infection can lead to death.

What to do if you develop COVID-19 symptoms

If you have COVID-19 symptoms, please stay home while you are sick and work from home if possible. You should stay home until;

  • your symptoms improve
  • you have been fever-free for 24 hours
  • you have been diarrhea- and vomit-free for 48 hours.

If respiratory illness symptoms worsen, or if you do not notice improvement after 5 or 6 days, call your primary care provider or Telecare 811.


If your symptoms have started within the last 5 days, and you are at higher risk for severe outcomes, you may be eligible for treatment and should consider getting a COVID-19 test. 

Register to pick up at-home rapid test kits

If you are having difficulty breathing or are experiencing other severe symptoms, call 911 immediately.

COVID-19 variants

Genetic variations of viruses, such as the one that causes COVID-19, are common and expected.

SARS-CoV-2, the virus that causes COVID-19, will naturally develop mutations, which are changes to the genetic material in the virus over time.

When there have been several significant mutations to the virus then it’s called a variant. A variant is of concern when it affects:

  • disease spread
  • disease severity
  • tests used to detect the virus
  • vaccines and treatments

Monitoring the variants

The Public Health Agency of Canada works with the provinces and territories, and other partners to monitor and identify variants of concern in Canada. We’re following the first identified variants in the United Kingdom, Brazil and South Africa. Monitoring for genetic changes in the virus allows us to understand better the potential impact of the mutations.

The National Microbiology Laboratory (NML) have established some high priority criteria for sequencing.  Any specimens collected from persons who have travel-associated infection to impacted areas, cases suggestive of COVID-19 re-infection, infections occurring post COVID-19 vaccine, and investigation of super-spreader events, are forwarded to the NML for variant sequencing.

About the new variants

The new variants of concern include mutations that seem to make the virus more infectious, allowing it to spread more easily. 

Currently, there’s no conclusive evidence that these variants impact the effectiveness of authorized drugs and vaccines.

The variants don’t currently affect diagnosis through authorized laboratory tests.

Given the limited data on the new variants, more research is needed to confirm these early findings. The Canadian and global medical, public health and research communities are actively evaluating these variants and other significant mutations.