Coronavirus disease (COVID-19): Prevention and risks

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How COVID-19 spreads

COVID-19 spreads from an infected person to others through respiratory droplets and aerosols (smaller droplets) created when an infected person:

COVID-19 can also spread by touching something that has the virus on it, then touching your mouth, nose or eyes with unwashed hands. You can transmit COVID-19 before you start showing symptoms or without ever developing symptoms.

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Evidence indicates that vaccines are effective at preventing serious outcomes due to COVID-19, such as severe illness, hospitalization and death.

However, there's a small percentage of the population who are vaccinated that may still be infected with COVID-19 if they're exposed to the virus. As a result, you may be asked to get a COVID-19 test.

Your vaccination status only changes your risk of getting COVID-19 and becoming sick. It doesn't change your risk of exposure to the virus out in the community.

Vaccination is also the best prevention against post COVID-19 condition. Post COVID-19 condition refers to symptoms some individuals experience for weeks or months after being infected with COVID-19. Symptoms can be very different from those during the initial infection.

The condition can affect both adults and children.

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Flu vaccination

Getting your yearly flu shot is the best way to help protect:

  • yourself
  • your family
  • your community
  • people at high risk of complications from the flu

The flu shot is available for anyone 6 months of age and over. Getting vaccinated against the flu every fall is important, but this year it's even more important.

The flu shot will not protect against COVID-19, but it will help reduce your risk of getting the flu and COVID-19 at the same time. Having both illnesses at the same time could put you at a higher risk for severe complications.

Getting the flu vaccine can also help prevent health care provider visits and hospitalizations from the flu. This helps lessen the burden on Canada's health care system during the COVID-19 pandemic.

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Prevention for individuals

While vaccines are having a significant impact on controlling the spread of COVID-19, the virus continues to circulate. Ongoing efforts continue across Canada to:

Public health measures remain an important part of our response to COVID-19 because:

Individual public health measures are actions you can take to help prevent the spread of COVID-19 and other illnesses, like flu. We've previously referred to these measures as personal preventive practices. These measures are most effective when layered together and used alongside vaccination.

Many individual public health measures were practised before COVID-19 to prevent the spread of other infectious illnesses. They should continue to be part of your everyday practices, today and always. This includes things like staying home when sick and regular hand hygiene. For the time being, you should also continue to wear a mask and maximize your physical distance from others for additional layers of protection.

You're encouraged to follow all individual public health measures regardless of your vaccination status. Recommendations for some measures are expected to change over time in response to the current COVID-19 situation.

Public health advice varies widely across Canada due to local situations. It's important that you:

At this time, it's unknown if COVID-19 will completely go away. Outbreaks or more seasonal patterns may begin to emerge, as seen with colds and flu.

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Stay at home when you're sick

You should continue to stay at home when you're sick. This will help reduce the risk of spreading COVID-19 and other illnesses.

Follow the instructions of your local public health authority on COVID-19 quarantine or isolation requirements.

If you develop symptoms of COVID-19 and you're outside your home, you should:

  • put on a medical mask or consider using a respirator
    • if unavailable, properly wear a well-constructed and well-fitting non-medical mask that includes a filter layer
  • isolate yourself away from others as quickly as possible
  • contact your health care provider or local public health authority and follow their advice

Be prepared to stay at home if you have symptoms of COVID-19 or need to care for someone who is sick.

If your illness or symptoms aren't COVID-19 related, consult with your health care provider to determine when you can return to regular activities.

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Improve ventilation

Ventilation plays an important role in reducing the risk of COVID-19 and other illnesses in indoor settings. Good ventilation exchanges indoor air for outdoor air, helping to reduce potentially infectious respiratory particle buildup in the air indoors. One way you can improve ventilation is by opening windows or doors.

When possible, consider holding or moving activities and gatherings outdoors.

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Wear a mask

Follow local public health advice on when you should wear a mask. Masks may be required or recommended in public settings, such as:

  • stores
  • schools
  • businesses
  • workplaces
  • public transit

Even if masks aren't required in your area or the setting you're in, wearing a mask is an added layer of protection. Whether you're vaccinated or not, you should consider wearing one in shared spaces with people from outside of your immediate household. This is especially important indoors, whether in public or private settings.

Masks are strongly recommended in any crowded setting, including settings with vaccination requirements.

Different types of masks are available for public use. Non-medical masks, medical masks and respirators can all be used in the community.

In general, while non-medical masks can help prevent the spread of COVID-19, medical masks and respirators provide better protection. Fit is important for all types of masks.

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Practise physical distancing

Physical distancing means maximizing your distance from others. You can do this by avoiding getting physically close to or having direct physical contact with other people.

Physical distancing may be required or recommended in public settings and is advised when in shared spaces with people you don't live with.

You don't need to physically distance from people in your immediate household. However, this may change if you or they are in quarantine or isolation.

Your immediate household is anyone who currently lives and shares common spaces in your housing unit (such as your house or apartment). This can include family members, as well as roommates or people who are unrelated to you.

When interacting with people from other households, continue to follow local public health recommendations and restrictions, including gathering size limits. Always consider the risks to you and the household members you're interacting with, and layer public health measures.

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Use caution in closed spaces and crowded places

The risk of COVID-19 is higher when you're around someone who has COVID-19 in closed spaces (with poor ventilation) and crowded places. You're at higher risk in settings where these factors overlap or involve activities such as:

  • singing
  • shouting
  • close-range conversations
  • heavy breathing (like during exercise)

If a space feels stuffy or smelly, it probably isn't well ventilated. If you feel the space isn't well ventilated or is too crowded, follow all individual public health measures while in that space. You may also choose to:

  • avoid that space
  • limit the amount of time spent in the space

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Practise hand hygiene and respiratory etiquette

Maintaining good hand hygiene and respiratory etiquette helps reduce the risk of becoming infected or spreading infection to others.

Hand hygiene means washing your hands often with soap and water for at least 20 seconds. If soap and water aren't available, use a hand sanitizer containing at least 60% alcohol. For example, clean your hands:

  • before and after eating or handling food
  • before and after touching a mask
  • before touching your eyes, nose or mouth
  • after using the washroom
  • after touching frequently touched surfaces and objects
  • after coughing or sneezing

Avoid touching your eyes, nose or mouth with unwashed hands.

Respiratory etiquette means, when coughing or sneezing, you should:

  1. cough or sneeze into a tissue or the bend of your arm, not your hand, if you're not wearing a mask
  2. dispose of any tissues you've used as soon as possible in a plastic-lined waste container
  3. clean your hands immediately afterwards

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Clean and disinfect surfaces and objects

How long the COVID-19 virus survives on surfaces and objects is unknown. Research shows that the virus may live on surfaces and objects for a few hours or up to several days depending on:

  • the type of surface or object
  • environmental factors such as humidity and temperature

It's also not certain to what extent contaminated surfaces or objects play a role in the spread of COVID-19.

Surfaces and objects that you or others frequently touch are most likely to become contaminated. Cleaning and disinfecting them can deactivate the virus, making it no longer infectious.

Health Canada has published a list of hard surface disinfectants that are likely to be effective for use against COVID-19. Use special precautions when cleaning with bleach to avoid serious incidents.

Paper mail or cardboard packages may be contaminated, but the risk of the virus spreading this way is very low. You don't need to clean and disinfect mail or packages. However, after handling mail, it is a good practice to avoid touching your eyes, nose or mouth until you can clean your hands.

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Follow all travel-related measures

It's important that you understand the risks and consider the impact your travel may have on you, your family and your community.

Travel restrictions continue to change around the world. These restrictions can change at a moment's notice. Many countries continue to experience COVID-19 transmission and have different levels of vaccination coverage.

To reduce your risk, continue to follow advice for travel outside of Canada.

  • Check the Government of Canada's travel advice and advisories before booking your trip.
  • Confirm the requirements for entry at your destination, which are:
    • testing and quarantine
    • acceptable vaccines
    • proof of vaccination required
  • Get fully vaccinated with a complete COVID-19 vaccine series at least 14 days before travelling.
    • Make sure you have a copy of your Canadian COVID-19 proof of vaccination.
  • Follow recommended public health measures during travel and while abroad.

If you've been on a recent cruise, check if you've been exposed during travel.

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Prevention for communities

As COVID-19 continues to circulate in Canada, governments and public health authorities will continue to:

Planners, administrators, operators and employers must work together to protect:

Canada is also supporting Indigenous communities as they continue to monitor and respond to COVID-19.

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Group living settings

Group living settings are places where many people who aren't in the same family unit live together. They may live there for a short or long period of time. Examples of these settings include:

  • student residences
  • construction trailers
  • industrial work camps
  • facilities for:
    • corrections
    • long-term care
  • agricultural worker dormitories
  • group homes for people with disabilities
  • shelters for people experiencing homelessness

These settings may include people who are at higher risk of exposure, or at risk of more severe disease or outcomes. Each setting should help prevent and reduce the spread of COVID-19 by:

  • consulting with their local public health authority
  • adapting public health measures that are appropriate for their setting

Learn more about limiting the spread of COVID-19 in certain group living settings:

Businesses and workplaces

COVID-19 can spread in businesses and workplaces. Employers and employees can take steps to protect workers, their families and the community, as well as clientele who access the settings.

Essential retailers and other workplaces have and may continue to adjust their operations to prevent and reduce the spread of COVID-19. If you're an operator, you can develop your risk reduction strategy using information from the following resources.

Child and youth settings

Operators of child and youth settings should be aware of COVID-19 risks and what measures they can take to lower them. These measures need to consider:

  • cultural, linguistic and social contexts
  • the diverse needs of children or young people
  • advice, guidance and resources from local public health authorities and partners

When developing a plan, local public health and education authorities, and their partners can use the following resources.

Outdoor spaces

Outdoor spaces and recreation are important to the health, well-being and social connections for all people. Compared to indoor settings, activities that occur outdoors are lower risk due to natural ventilation.

If you're in charge of an outdoor space or part of a recreation organization, refer to:

Public transportation

Public transportation includes transit such as:

  • ferries
  • rideshares
  • taxi or limo services
  • buses, trains and subways
  • shared bikes, skateboards and other micro-mobility devices

Layer multiple individual public health measures while on public transportation and in transportation hubs. This includes:

  • improving ventilation
    • open multiple operable windows
    • ask the driver to turn off the re-circulated air function
  • wearing a mask
  • maintaining physical distancing
  • cleaning your hands regularly

If you can, try to choose transportation that isn't crowded. For example, commute during off-peak hours.

Do not use public transportation to seek medical care if you feel sick or have any symptoms of COVID-19, even if mild.

Public transportation workers, administrators and engineers should follow advice on how to reduce the risks on the job.

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Organizations that serve people experiencing homelessness

People who experience homelessness may be at risk of more severe disease or outcomes. They may also have a greater risk of exposure to COVID-19 because they may:

  • not be able to access or use traditional services or resources
  • have limited ability to follow public health measures due to financial or environmental barriers
  • stay in shelters or other group settings with many other people

Organizations, community health workers and volunteers play an important role in helping prevent and reduce the spread of COVID-19 among those who experience homelessness.

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Risks of getting COVID-19

The risk of getting COVID-19 is evolving daily and varies between and within communities. Risk is dependent on:

To protect yourself and others:

Resources are available to help you make informed decisions on your personal risk when going out and visiting others.

People at a greater risk of exposure

You may be more likely to be exposed to the COVID-19 virus if there are high or increasing levels of COVID-19 spread in your community and:

  • you spend time around people who aren't fully vaccinated
  • you're caring for someone who has or may have COVID-19
  • your job or occupation requires you to be in contact with large numbers of people
  • you live in a crowded home (such as a multi-generational household) or group setting where the COVID-19 virus may transmit more easily, such as:
    • correctional facilities
    • long-term care facilities
    • shelters or group residences
  • you face social, economic or personal barriers that limit your ability to access or put in place effective public health measures
    • for example, individuals with disabilities who encounter non-accessible information, services or facilities

Your vaccination status only changes your risk of getting COVID-19 and becoming sick. It doesn't change your risk of exposure to the virus out in the community.

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People at risk of more severe disease or outcomes

COVID-19 can result in severe illness for some people in our communities. Those who are at risk of developing more severe disease or outcomes from COVID-19 are people:

  • who aren't fully vaccinated
  • who are pregnant
  • who are an older adult (increasing risk with each decade, especially over 60 years)
  • of any age with chronic medical conditions, including:
    • lung disease
    • heart disease
    • high blood pressure
    • diabetes
    • kidney disease
    • liver disease
    • dementia
    • stroke
  • of any age who are immunocompromised, including those:
    • with an underlying medical condition, such as cancer
    • taking medications which lower the immune system, such as chemotherapy
  • living with obesity, such as having a body mass index (BMI) of 40 or higher

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Pregnant people

There are a number of important factors to consider for pregnant individuals during the COVID-19 pandemic. This includes:

  • your risk of exposure to COVID-19
  • the risk of more severe disease or outcomes if you get COVID-19 while pregnant

It's important to talk to your health care provider.

If you do get COVID-19 while you're pregnant, you may have an increased risk of more severe disease or outcomes. The National Advisory Committee on Immunization recommends you get a complete series with an mRNA vaccine if you're pregnant or breastfeeding.

The risk of severe disease or outcomes appears to be worse with some COVID-19 variants. It's important to continue regular prenatal visits during COVID-19, even if completed virtually.

If you're pregnant and concerned about COVID-19, speak to your health care provider.

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Sexual health

Sexual health is an important part of overall health, but can be complicated during the pandemic for intimate partners who:

  • aren't part of the same immediate household
  • are at:
    • greater risk of exposure to COVID-19
    • risk of more severe disease or outcomes from COVID-19

Kissing and physical intimacy with partners who may be infected and are outside of your immediate household can put you at risk of getting COVID-19. Even if the infected person isn't showing symptoms, they can still transmit the virus. Sexual activity is safer if both partners are fully vaccinated.

Current evidence indicates there's a very low likelihood of getting COVID-19 through semen or vaginal fluids. The main way of spreading the virus is typically respiratory fluids. If having sex with someone from outside of your immediate household, reduce the risk to yourself and others by:

  • making sure all partners are fully vaccinated
  • following recommended individual public health measures
  • limiting the use of alcohol and other substances so you and your partner(s) are able to make safe decisions

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Going out or being social safely during COVID-19

Think about the risks before going out and make informed decisions. Keep yourself and others safe when participating in personal and social activities during the COVID-19 pandemic.

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Gatherings, events and celebrations

Gatherings, events and celebrations are lowest risk when with people from your immediate household. If choosing to gather with people from outside your immediate household:

  • follow local public health advice
  • choose lower-risk activities and settings
  • layer multiple public health measures to reduce the risk

For organizations and businesses hosting gatherings and events, follow the advice from your local public health authority and use our tool to reduce risk for gatherings and events.

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There's no evidence that COVID-19 can spread through water. To reduce the risk of spread from person to person when swimming, continue to follow recommended individual measures, particularly when in:

  • change rooms
  • public washrooms
  • crowded public indoor swimming pools and decks

You shouldn't wear a mask when swimming, as they aren't effective under water and make breathing difficult. If a mask is required in the setting you're in, then you should put one on after you exit the water.

Swimming in water outdoors, such as lakes or rivers, is much lower risk due to natural ventilation.

Avoid sharing swimming gear with others as COVID-19 may also spread through contaminated surfaces and objects. If you have to share swimming gear, clean and disinfect it between users.

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There's currently no evidence to suggest that food is a likely source of COVID-19, as there are no reported instances.

We're continually working to examine new scientific evidence between food safety and COVID-19. Scientists and food safety authorities around the world are also working closely to share information on COVID-19 and its relation to food safety. We'll continue to update Canadian food safety practices based on the most relevant and recent scientific findings.

Individual measures such as hand hygiene can help to reduce the risk of foodborne illnesses.

If we become aware of a potential food safety risk, we'll take appropriate actions to ensure the safety of Canada's food supply.

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There's limited information about animals and COVID-19, especially about if animals can spread the virus. In most cases, people are infecting animals (human-to-animal transmission). According to the World Organisation for Animal Health, there haven't been any reports of pets spreading COVID-19 to people.

The Public Health Agency of Canada tracks and analyzes research and case reports about animals and COVID-19 from around the world.

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