COVID-19: Spread, prevention and risks

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How COVID-19 spreads

COVID-19 can spread in different ways. Most of the time, it spreads when people are in close contact with others who are infected with the virus. You can transmit COVID-19 even before showing symptoms or without developing symptoms.

An infected person releases infectious respiratory particles into the air when they:

These particles can land on another person, the ground or onto nearby surfaces. They may also linger in the air, especially in poorly ventilated indoor spaces.

You may become infected if:

Contact with contaminated surfaces or objects

You may become infected if you touch a contaminated surface or object, and then touch your eyes, nose or mouth before you clean your hands.

High-touch surfaces and objects are more likely to be contaminated, including:

Studies show that the virus can stay active on surfaces and objects from a few hours to days, depending on the type of surface and environment.

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Animals

Based on available information to date, animal-to-human transmission is very uncommon.

People with COVID-19 can spread the virus to animals during close contact. To prevent possible infection, anyone with suspected or confirmed COVID-19 should avoid contact with:

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Food

There's currently no evidence to suggest that food is a source of COVID-19. There haven't been any confirmed cases of COVID-19 being spread through food or food packaging.

Follow safe food handling advice to help reduce your risk of foodborne illnesses.

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Preventing COVID-19

Vaccination is one of the most important ways to protect yourself from developing serious complications from COVID-19. It's important to stay up to date with your vaccinations. Evidence shows that the COVID-19 vaccines used in Canada are very effective at preventing severe illness, hospitalization and death from COVID-19.

In addition to vaccination, use personal protective measure to help protect yourself and others.

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Personal protective measures

Personal protective measures are effective actions you can use every day to help reduce the risk of getting or spreading COVID-19. It's best to use multiple personal protective measure at the same time.

Stay informed about COVID-19 disease activity in your area. Think about your risks and make informed decisions on using personal protective measures to keep yourself and others safe.

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Risks of getting COVID-19

COVID-19 will continue to spread at different levels in our communities, and outbreaks will still occur. New variants of concern may also emerge.

There's also uncertainty around how long immunity from vaccination and previous infection lasts.

We know that COVID-19 is most frequently transmitted when people are in close contact with others who are infected with the virus, especially when indoors. The risk is higher if people are also singing, shouting or breathing heavily (like when exercising) in these settings.

Some settings will be higher risk, including those that:

Some high-risk settings may have measures in place to help prevent the spread of illness. Recommendations may vary for different public settings. Always follow the measures that a specific setting has put in place.

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Who is most at risk

You may be at risk of more severe disease or outcomes from COVID-19 if you:

If you're at higher risk, it's even more important that you reduce your risk of getting the virus. This means you should receive recommended vaccines and use personal protective measures in higher-risk settings.

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Recommendations for travellers

Don't travel if you're sick with COVID-19-like symptoms.

In general, it's important to talk to a health care provider or visit a travel health clinic preferably about 6 weeks before your trip to get personalized health advice. Even if your travel date is coming up soon, it's still worthwhile to make an appointment.

Review the travel advice and advisories page for your destination. The 'Health' section has information on the health risks at your destination and the steps you can take to reduce those risks.

Travel advice and advisories by destination

While abroad, protect your health and the health of others by:

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