Topic Overview

What are immunizations?

Immunizations save lives. They are the best way to help protect you or your child from certain infectious diseases. They also help reduce the spread of disease to others and prevent epidemics. Most are given as shots. They are sometimes called vaccines, or vaccinations.

In many cases when you get a vaccine, you get a tiny amount of a weakened or dead form of the organism that causes the disease. This amount is not enough to give you the actual disease. But it is enough to cause your immune system to make antibodies and cells that can recognize and attack the organism if you are ever exposed to it.

Sometimes a vaccine does not completely prevent the disease, but it will make the disease much less serious if you do get it.

Some immunizations are needed only one time. Others require several doses over time to help your body be able to fight the disease (build immunity).

What are some reasons to get immunized?

• Immunizations protect you or your child from dangerous diseases.
• They help reduce the spread of disease to others.
• They are often needed for entrance into school or daycare. And they may be needed for employment or for travel to another country.
• The risk of getting a disease is much greater than the risk of having a serious reaction to the vaccine.
• When immunization rates drop below a certain level, preventable diseases show up again. Often these diseases are hard to treat. For example, measles outbreaks still occur in Canada.

If you are a woman who is planning to get pregnant, talk to your doctor about what immunizations you have had and what you may need to protect your baby. And if you live with a pregnant woman, make sure your vaccines are up-to-date.

Travelling to other countries may be another reason to get immunized. Talk with your doctor months before you leave, to see if you need any shots or other medicines.

What immunizations are recommended for children and adolescents?

Childhood immunization schedules may vary in each province and territory. Ask your health professional what shots your child should get. Other shots may be recommended too, if your child is more likely to have certain health problems.

The Canadian National Advisory Committee on Immunization (NACI) provides recommendations for the use of vaccines in Canada, but specific immunization schedules are developed by provincial and territorial health authorities. Commonly recommended immunizations include:^{footnote 1}

• Bacterial meningitis.
• Chickenpox.
• Diphtheria, tetanus, and pertussis (also known as whooping cough).
• Influenza (flu).
• Haemophilus influenzae type b disease, or Hib disease.
• Hepatitis A.
• Hepatitis B.
• Human papillomavirus (HPV).
• Measles, mumps, and rubella.
• Pneumococcal disease.
• Polio.
• Rotavirus.

Immunizations start right after birth, and many are given throughout a baby's first 23 months. Booster shots (the later doses of any vaccines that need to be repeated over time) occur throughout life.

Fewer immunizations are needed after age 6. But older children and adolescents need shots too. Talk with your health professional about the specific vaccines that your child or teenager may need. Some shots are also given during adulthood (such as a tetanus shot).

It is important to keep a good record, including a list of any reactions to the vaccines. When you enroll your child in daycare or school, you may need to show proof of immunizations. Your child may also need the record later in life for university, employment, or travel.

Talk to your health professional if you or your child plans to be in a group living situation, like a university dormitory or summer camp. You may want certain shots, like those for meningitis.

What vaccines are recommended for adults?

The vaccines you need as an adult depend not only on your age, lifestyle, overall health, pregnancy status, and travel plans but also on who you are in close contact with and what vaccines you had as a child.

Talk to your health professional about which vaccines you need. Common adult vaccines include:

• Influenza (flu).
• Human papillomavirus (HPV).
• Pneumococcal.
• Shingles.
• Tetanus, diphtheria, and pertussis.

What are the side effects of vaccines?

Most side effects from vaccines are minor, if they occur at all. Ask your health professional about the reactions that could occur. They may include:

• Redness, mild swelling, or soreness where the shot was given.
• A slight fever.
• Drowsiness, crankiness, and poor appetite.
• A mild rash 7 to 14 days after chickenpox or measles-mumps-rubella shots.
• Temporary joint pain after a measles-mumps-rubella shot.

Severe reactions, such as trouble breathing or a high fever are rare. If you or your child has an unusual reaction, call your doctor.

How safe are vaccines?

False claims in the news have made some parents concerned about a link between autism and the shot for measles, mumps, and rubella. But studies have found no link between vaccines and autism.^{footnote 2, footnote 3}

Some parents question whether mercury-containing thimerosal (used as a preservative in vaccines) might cause autism. Studies have not found a link between thimerosal-containing vaccines and autism.^{footnote 4, footnote 5} Today, all routine childhood vaccines made for Canada contain either no thimerosal or only trace amounts.^{footnote 6}

Childhood Immunizations

Recommended immunizations

Childhood immunization recommendations and schedules may vary by province and territory. Immunizations are recommended because they protect against diseases (give immunity) or make a disease less severe if your child does get it. These schedules outline the immunizations and booster shots needed from birth through age 18, as well as when catch-up immunizations should be given.

The schedule for a premature infant is the same as for a full-term infant. But sometimes the hepatitis B vaccine is delayed.

Many immunizations require more than one dose, given at varying intervals. Although your child does not need to restart the series if a scheduled dose is missed, the immunization should be given as soon as possible. Consult your health professional or public health unit if your child missed an immunization or to find out whether your child needs a specific immunization.

The Canadian National Advisory Committee on Immunization (NACI) provides recommendations for the use of vaccines in Canada. But specific immunization schedules are developed by provincial and territorial health authorities. Commonly recommended immunizations include:^{footnote 1}

Chickenpox (varicella)

This shot protects against chickenpox.

Who should get it?

• All children 12 months of age and older who have not had chickenpox should get one dose at 12 to 15 months of age. Another dose may be given at a later time in some provinces.

The combination MMRV shot can be given in place of the chickenpox vaccine. The vaccines for chickenpox, measles, mumps, and rubella are all in this one shot.

Diphtheria, tetanus, and pertussis (DTaP)

This shot (immunization) protects against diphtheria, tetanus, and whooping cough (pertussis).

Who should get it?

• All children are given four or five doses starting at age 2 months and ending around age 4 to 6 years.
• The first several doses may include the hepatitis B, polio, and Hib vaccines (DTaP-HB-IPV-Hib).

Influenza (flu)

This immunization helps protect against influenza. Influenza viruses are always changing, so the influenza vaccines are updated every year.

Who should get it?

• The National Advisory Committee on Immunization (NACI) and the Canadian Paediatric Society (CPS) recommend that everyone older than 6 months of age have an influenza vaccine once a year. But it is especially important for people who have a high risk of having complications from the flu, including:^{footnote 7}
  • All children 6 through 59 months of age.
  • Children with certain medical conditions (such as asthma, chronic heart or lung disorders, or an impaired immune system).
  • Close contacts, including household contacts and out-of-home caregivers, of children 59 months of age and younger who are at high risk for complications from influenza.

There are different ways to get a flu vaccine. Ask your child's doctor what is right for your child. Visit https://www.canada.ca/en/public-health.html for more information about the flu vaccine.

Haemophilus influenzae type b (Hib)

This shot protects against a bacteria that can cause an infection in the lungs (pneumonia) or the covering of the brain (meningitis), skin and bone infections, and other serious illnesses in young children. It does not protect against viral influenza (flu).

Who should get it?

• All children need three or four doses, starting at 2 months of age and ending by 23 months of age.
• Children who are older than 5 years and have certain health conditions may also need this shot.
• This shot is usually given in combination with the diphtheria, tetanus, whooping cough (pertussis), hepatitis B, and polio vaccines (DTaP-HB-IPV-Hib).

Hepatitis B (Hep B)

This shot protects against hepatitis B.

Who should get it?

• All babies need at least three doses. The first dose may be given right after birth (before leaving the hospital) or at age 2 months. The remaining doses are given by 6 to 24 months of age.

Measles, mumps, and rubella (MMR)

This shot protects against measles, mumps, and rubella.

Who should get it?

• All children need one dose at 12 months of age and a second dose after 15 months. To make it easy on parents, some provinces and territories may recommend that the second shot is given with other vaccines: at 18 months or between 4 and 6 years of age, before starting school.

There is a measles, mumps, rubella, and varicella (MMRV) shot that also protects against chickenpox (varicella). Talk to your child's doctor about the pros and cons of the MMRV shot. It can be given to children ages 12 months to 12 years.

Meningococcal disease

This shot protects against meningitis and blood infections (sepsis).

Who should get it?

• Children may get the vaccine starting at 2 months of age. Provincial guidelines or your doctor's recommendations determine the ages the shot is given. All children should get a booster dose at 12 to 24 months of age even if they were vaccinated as a baby.
• In children ages 1 to 4 years, a single dose can be given, and it may be considered for children age 5 and older who have not been immunized.

Children 2 and older who have a high risk for getting and having severe problems from meningitis should also have another type of meningococcal vaccine. These children include those who have a damaged or missing spleen or who have certain immune system problems.

Pneumococcal infections

This shot protects against meningitis, blood infections (sepsis), pneumonia, and ear infections.

Who should get it?

• Depending on the recommendations of your province, children get 3 or 4 doses starting at 2 months of age.
• Children who did not get the shot as babies can get catch-up doses up to age 5.
• Children ages 5 to 18 may need the shot if they did not get it as a baby or if they have certain medical conditions that make them high risk for getting a pneumococcal infection.

Polio

This shot protects against polio.

Who should get it?

• Four or five doses are given to all children starting at age 2 months and ending around age 4 to 6 years.
• The first four doses may be given in combination with the diphtheria, tetanus, whooping cough (pertussis), and Hib vaccines (DTaP-IPV-Hib).

Rotavirus vaccine

This immunization protects against rotavirus infection, which causes severe diarrhea.

Who should get it?

• There are two brands of this vaccine. Your child will get 2 or 3 doses between the ages of 2 and 6 months depending on which brand is used. It is swallowed rather than given as a shot.

Other immunizations

Your child's doctor or health professional may recommend other immunizations, depending on the recommendations in your province and whether your child is at higher risk than other children for certain health problems. Some of these other immunizations may include:

Hepatitis A (Hep A)

This shot protects against hepatitis A disease.

Who should get it?

• Anyone 6 months of age or older who lives in a community where there is increased risk for hepatitis A or who will travel to a foreign country where hepatitis A is common.

Combination vaccines

Combination vaccines may be preferred to separate shots because they reduce the number of needle pricks.

Keeping good immunization records

It is important to keep accurate records of immunizations, including any reactions to the vaccines. When you enroll your child in daycare or school, you may need to show proof of immunizations. Also, your child may need the record later in life for university, employment, or travel.

• Know when each immunization should be scheduled, and put reminder notes on your calendar. You also may want to ask your doctor to send you notices when immunizations are due.
• Have your doctor go over your child's immunization record with you during each office visit.
• Keep the record in a safe place, and never throw it away. It is an important part of your child's lifelong medical records.

Immunization safety

You may worry that immunizations are dangerous if given when your child has a cold or other minor illness. Talk to your child's doctor if you have concerns about the timing of immunizations. Immunizations can usually still be given during a mild illness, while medicines are being taken, and in other situations where a child may not be in perfect health. Also, getting several vaccines at the same time is as safe as getting one shot at a time.^{footnote 8} There are very few reasons for which doctors suggest that a person postpone or not get an immunization.

Some parents fear that the measles-mumps-rubella (MMR) vaccine may cause their child to develop autism. Misleading stories about the MMR shot and autism have circulated through websites, the media, and word of mouth. But scientific studies have found no connection between autism and the vaccine.^{footnote 9}

Adolescent Immunizations

Recommended immunizations

Adolescents need certain immunizations and booster shots for ongoing protection (immunity) against diseases. Consult your health professional or public health unit if your child missed an immunization or if you need to find out whether your child needs a certain one.

The Canadian National Advisory Committee on Immunization (NACI) provides recommendations for the use of vaccines in Canada. But specific immunization schedules are developed by provincial and territorial health authorities. Commonly recommended immunizations for adolescents include:^{footnote 1}

Influenza (flu)

This immunization helps protect against seasonal influenza. Influenza viruses are always changing, so the influenza vaccines are updated every year. Protection lasts up to a year.

Who should get it?

• The National Advisory Committee on Immunization (NACI) suggests everyone 6 months and older have a yearly influenza vaccine.
• Adolescents with certain health conditions, such as asthma, chronic heart or lung disorders, or an impaired immune system, should get a yearly influenza vaccine.
• Siblings or close contacts of all children 59 months of age and younger and of anyone who is in a high-risk category for complications of influenza should be immunized each year.

There are different ways to get a flu vaccine. Ask your child's doctor what is right for your child. Visit https://www.canada.ca/en/public-health.html for more information about the flu vaccine.

For more information about influenza, see the topic Influenza (Seasonal Flu).

Human papillomavirus (HPV)

The HPV (human papillomavirus) vaccine protects against HPV. HPV is a common sexually transmitted infection (STI). There are many types of HPV. Some types of the virus can cause genital warts. Other types can cause cervical or oral cancer and some uncommon cancers, such as vaginal and anal cancer. The HPV vaccine protects against the most common HPV types that can cause serious problems.

Who should get it?

• The National Advisory Committee on Immunization (NACI) recommends the vaccine for females and males. It can be given starting at age 9.^{footnote 10}

If your child already has HPV infection, talk with your doctor about whether to get your child immunized. The shot has not been shown to help existing HPV infection, but it may protect your child from other HPV infections.

Tetanus, diphtheria, and pertussis booster (Tdap)

This shot protects against tetanus, diphtheria, and whooping cough (pertussis).

Who should get it?

• All teenagers at around 14 to 16 years of age.

Adolescents who only received the booster for tetanus and diphtheria (Td) should wait about 2 years before getting the Tdap booster.

Meningococcal vaccine

This shot protects against meningitis and blood infections (sepsis). There are different meningococcal vaccines that protect people against certain strains of meningitis bacteria: conjugate and polysaccharide.

Who should get it?

• Adolescents should get a meningococcal conjugate at around age 12 to 15, even if they received it as a child. It is especially important that adolescents and young adults get the shot if they:
  • Have an increased chance of becoming infected during an outbreak.
  • Have a damaged spleen or have had the spleen removed.
  • Live in or travel to areas of the world where meningococcal disease is common, such as to certain parts of Africa or to Saudi Arabia during the Hajj.
  • Are military recruits.

Other immunizations

Some adolescents may need or want more immunizations for situations that increase a person's risk for exposure to disease, such as being in group living situations (when attending university or summer camp) or travelling to other countries. They may have missed shots when they were younger. Or a vaccine may not have been offered when they were younger. These immunizations may include:

Chickenpox (varicella)

This is important if your child never had chickenpox or never got this shot.

This shot protects against chickenpox.

Who should get it?

• Adolescents and adults who are not already immune to the chickenpox virus need this shot. Anyone who gets this shot at age 13 or older should get two doses at least 6 weeks apart.

Chickenpox infection can be very serious when it occurs after childhood.

Hepatitis A (Hep A)

This shot protects against hepatitis A disease.

Who should get it?

• Adolescents who live in communities where there are outbreaks of hepatitis A.
• Adolescents who live in an area where there is increased risk for hepatitis A.
• Adolescents who are travelling to certain foreign countries also need this shot.

Hepatitis B (Hep B), if not previously received

This is important if your child never got this shot.

This shot protects against hepatitis B disease.

Who should get it?

• Anyone 18 years of age or younger who has not had this shot should get three doses over a period of about 6 months.

Measles, mumps, and rubella (MMR)

This is important if your child never got this shot.

This shot protects against measles, mumps, and rubella. There is a measles, mumps, rubella, and varicella (MMRV) shot that also protects against chickenpox (varicella). It can be substituted for either or both doses of MMR in children ages 12 months to 12 years.

Who should get it?

• If your child did not get either or both doses, he or she should try to get immunized at age 11 or 12.

Pneumococcal polysaccharide vaccine (PPV)

This shot does not necessarily reduce the risk of getting pneumonia. But it can prevent some of the serious complications of pneumonia, such as blood infections (sepsis).

Who should get it?

• Adolescents with certain chronic diseases, such as diabetes or heart disease, need this shot.
• Some adolescents at high risk for pneumococcal infection may also get a second type of vaccine called pneumococcal conjugate vaccine (PCV).

Immunization safety

Most side effects from vaccines are minor, if they occur at all. The doctor may have your child stay in the office for up to 15 minutes after the shots are given, to watch for any reactions.

You may worry that immunizations are dangerous if they are given when your child has a cold or other minor illness. Talk to your child's health professional if you have concerns about the timing of shots. But keep in mind that shots can usually still be given during a mild illness, while medicines are being taken, and in other situations where a child may not be in perfect health. There are very few reasons for which health professionals suggest that a person postpone or not get an immunization.

Adult Immunizations

Recommended immunizations

Your need for immunizations does not end when you reach adulthood. The specific vaccines you need as an adult depend not only on your gender, age, lifestyle, overall health, pregnancy status, and travel plans but also on who you are in close contact with and what vaccines you had as a child. Tetanus and diphtheria shots need to be repeated every 10 years throughout adulthood in order to keep your immunity.

The Canadian National Advisory Committee on Immunization (NACI) provides recommendations for the use of vaccines in Canada. But specific immunization schedules are developed by provincial and territorial health authorities. Commonly recommended immunizations for adults include:^{footnote 1}

Influenza (flu)

This immunization helps protect against seasonal influenza. Influenza viruses are always changing, so the influenza vaccines are updated every year. Protection lasts up to a year for each flu vaccine type.

Who should get it?

• All adults need one dose each year. It is especially important for:
  • People at higher risk of severe flu.
  • Close contacts of people who are at higher risk, including people who live with or care for children younger than 6 months.

There are different ways to get a flu vaccine. Ask your doctor what is right for you.

Hepatitis A (Hep A)

The shots protect against hepatitis A.

Who should get it?

• Adults who live in communities where outbreaks of hepatitis A have recently occurred need the shots.
• Adults who live in a community where there is increased risk for hepatitis A.
• Adults who will be travelling to certain foreign countries also need two doses given at least 6 months apart.
• Adults who have certain risk factors, such as long-term (chronic) liver disease also need two doses.

Hepatitis B (Hep B)

This shot protects against hepatitis B disease. Three doses are needed over 6 months.

Who should get it?

• Adults who have not received the vaccine series for hepatitis B need this shot when their work, travel, health condition, or lifestyle increases their risk of exposure.

A hepatitis combination vaccine is recommended for those who are at risk for both hepatitis A and hepatitis B.

Pneumococcal polysaccharide (PPV)

This shot protects against meningitis, pneumonia, and blood infections (sepsis).

Who should get it?

• All people 65 years of age and older need this shot.
• Adults age 18 to 64 who have a chronic disease (such as heart, liver, or lung disease), do not have a spleen, or have a damaged spleen also need this shot.
• People who smoke or are dependent on alcohol should also get the vaccine.

This vaccine is different than the pneumococcal conjugate vaccine (PCV) that is recommended for children. Most adults only need one dose of PPV for protection. Adults with immune system problems or who have had a bone marrow stem cell transplant will need to get both the PPV and PCV vaccines. Some people might need to get a booster shot after 5 years.

In some cases, adults over 65 years of age who have normal immune systems may be able to get PCV to have additional protection from pneumococcal infections.

Shingles (herpes zoster)

This shot protects against shingles.

Who should get it?

Adults age 50 and older need the vaccine, whether or not they've had shingles before. Check with your provincial health plan to see if the shot is covered for you.

Tetanus and diphtheria (Td) or Tetanus, diphtheria, and pertussis (Tdap)

This shot protects against tetanus, diphtheria, and whooping cough (pertussis).

Who should get it?

• All adults need Td boosters every 10 years throughout life.

Other immunizations

You may need or want more immunizations if certain situations raise your chance for exposure to disease. Or you may have missed shots when you were younger. Or a vaccine may not have been offered when you were younger. These immunizations may include:

Chickenpox (varicella)

This shot protects against chickenpox. Chickenpox infection can be very serious when it occurs after childhood.

Who should get it?

• Adults who are not already immune to the chickenpox virus need two doses, given at least 6 weeks apart.

Pregnant women and people with immune system problems should not receive this shot.

Not all provincial or territorial health plans cover the cost of chickenpox shots for adults. You may have to pay for them yourself.

Human papillomavirus (HPV)

The HPV (human papillomavirus) vaccine protects against HPV. HPV is a common sexually transmitted infection (STI). There are many types of HPV. Some types of the virus can cause genital warts. Other types can cause cervical or oral cancer and some uncommon cancers, such as vaginal and anal cancer. The HPV vaccine protects against the most common HPV types that can cause serious problems.

Who should get it?

• The National Advisory Committee on Immunization (NACI) recommends the vaccine for females and males ages 9 to 26. The vaccine may also be given to adults ages 27 to 45 who didn't get the vaccine when they were younger.^{footnote 10}

Provincial health plans may not cover the cost of these immunizations outside of school-based immunization programs. You may have to pay for the vaccine.

If you already have HPV infection, talk with your doctor about whether to get immunized. The shot has not been shown to help existing HPV infection, but it may protect you from other HPV infections.

Measles, mumps, and rubella (MMR)

This shot protects against measles, mumps, and rubella.

Who should get it?

• Adults born after 1970 may need MMR vaccination if they do not have evidence of immunity.

Women should avoid becoming pregnant for 28 days after getting the MMR shot. Women who are known or suspected to be pregnant should not receive the MMR vaccine.

Meningococcal

This shot protects against meningitis and blood infections (sepsis).

Who should get it?

• Anyone 2 years of age and older should be considered for the meningococcal vaccine if they:
  • Have an increased risk of becoming infected during an outbreak.
  • Have a damaged spleen or have had the spleen removed.
  • Live in or travel to areas of the world where meningococcal disease is common, such as to certain parts of Africa or to Saudi Arabia during the Hajj.
  • Are a military recruit.

Polio (IPV)

This shot protects against polio.

Who should get it?

• Adults who have not been immunized or whose jobs or travel puts them at increased risk for exposure to polio need this shot.

Consult your health professional or public health unit if you missed an immunization or to find out whether you need a specific immunization.

Immunizations and pregnancy

Before you become pregnant, discuss your immunization history with your health professional. Your immunity protects both you and your baby. Some vaccines (such as the ones for flu and Tdap) can be given during pregnancy. Some vaccines need to be given before or soon after pregnancy.

If you are pregnant, your children should still get their immunizations on schedule. You do not need to speed up or delay your other children's immunizations.

Immunization safety

You may worry that immunizations are dangerous if they are given when you have a cold or other minor illness. Talk to your health professional if you have concerns about the timing of shots. But keep in mind that shots can usually still be given during a mild illness, while medicines are being taken, and in other situations where you may not be in perfect health. There are very few reasons for which doctors suggest that a person postpone or not get an immunization.

Travel Immunizations

Recommended immunizations

Talk with your health professional months in advance of a trip to find out whether any immunizations are recommended. Certain things, such as your age and health, where you are going, and the length of your stay, affect your risk of disease and your need for immunization.

Your age and health

People with certain medical conditions, such as immune system problems, may have different immunization recommendations than healthy people. Also, young children who are travelling may need to receive their routine immunizations sooner than normally scheduled.

Where you travel

In most developed countries (including the United States, Australia, New Zealand, Japan, and western and northern European countries), the risk of exposure to serious diseases is generally no greater than it is in Canada.

The risk of exposure to serious disease may be much higher in developing countries (such as those in most parts of Africa and Asia and many parts of South and Central America) than it is in most developed countries. This is especially true for areas with poor sanitation (for example, poor water and food handling). For example:

• If you are going to South America and Africa, you may need the yellow fever vaccine.
• Travellers to developing countries should take precautions to prevent hepatitis A infection, which includes getting immunized. Additional immunizations, such as typhoid vaccine, Japanese encephalitis, or rabies vaccine, may be recommended.

The need for these vaccines depends on your immunization history, the specific area you plan to visit, the time of year, and whether any outbreaks of disease have recently occurred.

How you travel and types of activities

Certain activities or modes of travel increase your risk of exposure to disease. These include:

• Exploring rural areas or those off the usual tourist route.
• Taking backpacking trips.
• Visiting people in another country.

Length of stay

The longer you stay in a country, the more exposure you have to local pathogens that could cause harm.

More information

You can get information about travel immunizations by:

• Contacting your local travel clinic, health unit, or health professional.
• Go to the Travel Health website of the Public Health Agency of Canada www.canada.ca/en/public-health/services/travel-health.html for more information.

Bioterrorism and Immunizations

The Canadian government has developed plans on how to respond to possible bioterrorism threats.

Certain diseases have been identified that pose the greatest threat to the Canadian public. At this time, there is a supply of anthrax and smallpox vaccines only. These immunizations are not currently available to or recommended for the general public. But the government has advised immunization for people at high risk of exposure to anthrax or smallpox, such as health care workers specifically designated to respond to a bioterrorism emergency. Some of these recommendations are listed below.

Anthrax vaccine

This shot protects against anthrax.

Who should get it?

• This shot is for people who are at high risk of exposure, such as certain lab workers, people who work with imported animals where preventive standards are lacking (such as veterinarians who travel to work in other countries), and certain military members.

Six shots are given over 18 months. And booster shots are needed every year for continued protection (immunity).

Smallpox vaccine

This shot protects against smallpox.

Who should get it?

• This shot is for certain health care and public health workers, infection-control specialists, and military members.

This shot is given once as several quick punctures on the upper arm, using a special prong device. Immunity after a first-time vaccination is likely to be 3 to 5 years. If you have been vaccinated in the past, successful revaccination may extend your immunity.

The Government of Canada has enough smallpox vaccine to vaccinate Canadians in an emergency.^{footnote 11}

Visit the Public Health Agency of Canada's Emergency Preparedness and Response website at www.canada.ca/en/public-health/services/emergency-preparedness-response.html for more information. For more general information about bioterrorism issues, see the topic Disasters and Other Public Health Threats.

When To Call

Call 911 or other emergency services if you or your child has:

• An allergic reaction, such as difficulty breathing, wheezing, hives, hoarseness, paleness, weakness, a fast heart rate, or dizziness
• Changes in behaviour, such as passing out (losing consciousness), acting confused, being very sleepy or hard to wake up, or not responding to being touched or talked to.
• A seizure
• Severe belly pain, nausea, vomiting, or diarrhea.

Call your doctor if:

• Redness and swelling at the site of the shot (injection) last longer than 48 hours.
• Your child is 6 months of age or younger and has a fever of 38 °C (100.4 °F) or higher.
• A fever lasts longer than a few days after a shot is given.
• Any unusual reaction occurs.
• Your child has mild belly pain or nausea.

Talk with your doctor about whether you need special immunizations because you:

• Are in close contact with people who have an infectious disease.
• Have planned international travel, especially to developing countries.
• Live with or visit a baby or someone who is pregnant.
• Live with someone who has an impaired immune system.

Home Treatment

Help your child handle immunizations

Many immunizations are given as shots (injections). Your child may experience brief pain as the needle penetrates the skin or muscle. Some vaccines cause more discomfort than others. In general, you can help decrease your child's discomfort by making sure that he or she is physically comfortable and well rested before getting immunized. You can use home treatment measures to help relieve some of the common minor reactions to immunizations.

Relieve mild reactions to immunizations

You can help relieve some of the common, temporary, mild reactions to immunizations with basic home care.

• Fever. A slight fever may occur after you or your child gets a shot. Acetaminophen (such as Tylenol) or ibuprofen (such as Advil) may help lower a fever. Follow the package instructions carefully. If you give medicine to your baby, follow your doctor or health professional's advice about what amount to give. Check with your doctor first if you are not sure your young baby's fever is related to getting immunizations. Do not give aspirin to anyone younger than 18 because of the risk of Reye syndrome, a rare but serious disease. For more information on fevers, see the topic Fever or Chills, Age 11 and Younger or Fever or Chills, Age 12 and Older.
• Swelling or redness. The area around the injection site may become red and swollen. Apply a wrapped ice pack or cool compress to the area for about 10 to 20 minutes. If this does not reduce the symptoms, acetaminophen or ibuprofen may help relieve the discomfort. Follow the package instructions carefully.
• Fretfulness and poor appetite. For a few hours after getting immunized, a baby may be fretful and drowsy and may refuse to eat. Plan quiet activities at home for the evening after your child receives an immunization. Hold and cuddle your child when needed. Keep your home at a comfortable temperature, because your child is more likely to be fretful if he or she gets too warm.
• Skin rash. A mild skin rash 7 to 14 days after your child gets the chickenpox or measles, mumps, and rubella (MMR) shot. These types of rashes can last several days and go away without treatment.

For more information about reactions to immunizations, see When to Call a Doctor.