Shedding light on common concerns about vaccines

There are many different opinions about vaccines: whether they are safe, whether they are still necessary, and who should get them.  

The purpose of this page is to present you with unbiased, reliable information about vaccination. The information presented is a summary of the Health Services’ team’s understanding of the latest evidence.

Making decisions about vaccines

It is important to apply critical thinking skills to your decisions about vaccinations. For an overview of critical thinking, check out our Critical Thinking section.

Most people have limited amount of time to collect, analyze, and evaluate information that will guide their health decisions. If you are doing your own research on the Internet be sure to know how to evaluate the reliability of information on the Internet. Immunize Canada has a fact sheet titled "Immunization Information on the Internet: Can you trust what you read?"    If you have very little time to dedicate to this, find one reliable source of information to refer to, such a trusted health care professional who has proven themselves reliable in the past.

Below we have listed some common public concerns about vaccines, and address them from an evidence-based perspective.

Shedding light on concerns about vaccines

Concern: Are vaccines safe?

The Public Health Agency of Canada — the government department responsible for promoting and protecting the health of Canadians — recommends that children and adults receive vaccinations.
 
Health Canada has a mandate to respect individual choices and circumstances: vaccination is not obligatory in Canada. Canadians choose whether or not to get vaccinated, or to vaccinate their children.

The vaccination debate

On the internet, you can read stories from people who believe they or their child suffered complications caused by a vaccine. You can also read about people who wish they or their child had received a life-saving vaccine.

As with all scientific work, vaccine research has some limitations: varying sample sizes for experiments; methodological challenges; the potential influence of drug manufacturers on policies and practices.

These concerns occasionally lead to public mistrust of a vaccine or a vaccination policy that is entirely beneficial. But there is no question about the scientific community’s position:

The benefits of getting vaccinated far outweigh any potential adverse consequences.

The risk of a vaccine causing serious harm is extremely small. In comparison, the risk of severe complications, hospitalization or death from vaccine-preventable diseases is much greater. The benefits of vaccination far outweigh the risks.

Concern: Are vaccines still necessary?

Because some people have never seen a case of measles, mumps, German measles, polio, diphtheria, tetanus, or whooping cough, they may feel that vaccines are no longer necessary. However, vaccines are vital for a few basic reasons:

• More likely to stay healthy:
  • Outbreaks of vaccine-preventable illnesses on college campuses are reported by the media every week. In the past year, Canadian and American universities have experienced outbreaks of measles, mumps, meningitis, and pertussis (whooping cough). Students were hospitalized, and some students died.
  • Vaccinated students are more likely to stay healthy when they are exposed to the illness. They will miss less work, school, and study time. 
    

• Less likely to spread illnesses to others:
  
  • Many people can have the virus or bacteria in their body, but they experience few or no symptoms because they are young and healthy. However, they still spread the infection to the people around them.
  • Many young people are very socially-minded, and express a sense of responsibility for others' well-being. Concordia, like other universities, serves students who are living with chronic illnesses, including diabetes, sickle cell anemia and HIV. These chronic illnesses increase these students' chance of complications when they get sick.
    
  • Many Concordia students are studying in the helping professions. These students have to complete placements with people who are more vulnerable to infections, including the elderly, people living with HIV, and people with Down Syndrome.

• Contribute to community immunity:
  • Unless a disease has completely disappeared, there is a real risk that small outbreaks can turn into large epidemics if most of the community is not protected.
  • Vaccines are not 100% effective! There will always be some people who are not immune, even though they have had their shots. Similarly, there are a small number of people who cannot receive vaccines. These people may have a severe allergy to a component of the vaccine, or a medical condition that makes receiving a vaccine too risky for them. These people are not protected from disease. They are protected when the people around them are immunized and cannot spread the disease to them. This is called ‘herd immunity’.
  • Most vaccine-preventable diseases are still common in other parts of the world. Travellers can carry them from country to country. If we are not protected by immunization, these diseases will quickly spread.

Can getting vaccinated make me sick?

All medication, including vaccines, have effects that you want (i.e.prevent illness), and also effects you could live without - side effects. However, side effects of vaccines are typically very mild compared to the real infection.

For example, after a flu shot, some patients have mild 'flu-like' symptoms such as a low fever and achy muscles. After receiving the varicella (chicken pox) vaccine, some patients develop a few blisters. However, these symptoms are typically very mild compared to the real infection. They resolve quickly and without the long-term, dangerous problems caused by the real infection.

The risk of a vaccine causing serious harm is extremely small. In comparison, the risk of severe complications, hospitalization or death from vaccine-preventable disease is much greater. The benefits of vaccination far outweigh the risks.

Concern: Are vaccines effective?

Vaccines work very well in preventing specific diseases. They are so effective that most of the diseases they prevent are now rare in Canada.

But vaccines are not magic! No vaccine is 100% effective: they lower your risk of getting and spreading the illness. You still have to wash your hands, get plenty of sleep, and eat healthy food. But vaccination is your best defence against vaccine-preventable illnesses.