A Parent's Guide to Immunization

Vaccines are safe

Vaccines are safe, with huge benefits to your baby's health - all through his life.

What is a vaccine?

A vaccine is the medicine in the needle when your baby is immunized. It is made of killed or weakened germs that help your baby's immune system learn how to protect itself. A vaccine protects your baby from getting very sick from the real disease.

How does it work to protect my child?

The killed or weakened germs in the vaccine trigger your baby's immune system to produce two important tools to fight off that disease in the future: special cells called antibodies and a useful immune memory of the disease.

Both tools help your child's body to be ready to recognize the germs and fight off vaccine-preventable diseases when they are exposed to them.

Most children are fully protected by immunization. It means that they will never get the disease. Some children get partial protection from immunization. This means that they may develop mild symptoms if they are exposed to the disease, but without the serious complications.

How can I be sure that vaccines are safe?

Vaccines are constantly monitored and tested around the world and in Canada before they are approved for use. Canada has several systems in place to keep a watchful eye on any reports of unusual side effects following immunizations.

Severe reactions from vaccines are extremely rare and are reported immediately to the Public Health Agency of Canada so that any problems can be dealt with quickly. The result is that our current vaccines are effective and safe. Vaccines are much safer than the serious vaccine-preventable diseases they prevent.

Can the vaccine make my baby sick?

No. Vaccines actually make your baby's immune system stronger by teaching it how to recognize and fight off infection. Your baby's natural immune system has no problem tackling and destroying the weak or dead germs in the vaccine. He may have a low fever and sleep more than usual or be cranky or fussy. These normal reactions usually last for a couple of days at the most following immunization.

Some people worry that vaccines can cause other health problems, such as autism, a lifelong developmental disorder. Medical researchers and scientists around the world have studied information collected over many years to see whether there is a link between vaccines and autism. Researchers have not found any evidence of a link between vaccines and autism or any other illnesses.