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Frequently Asked Questions

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Do vaccines weaken the immune system?

Vaccines do not weaken the immune system

The vaccines that are currently recommended do not overload or weaken your immune system. Infants and children are exposed to many kinds of germs every day, through normal eating, drinking and playing. Scientists estimate the immune system can recognize and respond to hundreds of thousands, if not millions, of different organisms.

  • The vaccines recommended for children and adults use only a small portion of the immune system's "memory".

Childhood vaccines are designed depending on the unique development of the infant immune system.

  • Vaccines offer immediate protection from common childhood illness and lay the foundation for lifelong immunity.
  • The recommended immunization schedule for infants in Canada is carefully timed to ensure that newborns and older babies get safe and effective protection from the diseases that are most likely to seriously harm them.

Vaccines strengthen the immune system

Vaccines strengthen the immune system to protect children and adults from specific diseases. Multiple vaccines make sure that your child is protected. Young children and babies show a safe and effective immune response. This is true even for newborn infants.

Infants need vaccines because they are more likely to get very sick from the diseases that vaccines can prevent, such as diphtheria, whooping cough and meningitis due to Haemophilus influenzae serotype b (Hib).

Vaccines work best when they're given at the right time as your child grows

Use the Immunization Schedule Tool to obtain your child's immunization schedule.

Other ways to find your immunization schedule

  • Contact your doctor or local public health office (CLSC in Quebec).
  • Use the links to your provincial or territorial immunization information.
  • For an immunization schedule for children older than 6 years of age, use the School-age Immunization Schedule tool.

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