Evaluating risk

Vaccines have extremely small risks.
The diseases that vaccines prevent, on the other hand, can kill you.

There's a risk from any medical procedure, and vaccines are no exception... but that risk is very small, especially compared to what you're risking from the diseases themselves.

For instance, there's a one in one million risk of encephalitis or an allergic reaction to the vaccine that prevents mumps. But for a child or adult who gets mumps, the risk of a potentially life-threatening disease like is 5,000 times higher.

Vaccines are one of the most monitored and studied things in medicine. (That's because they're given to healthy children, and health professionals don't want to do anything that would make a healthy child sick.) Severe adverse events from vaccines are extremely rare, and are closely monitored and tracked nationwide.

You need to focus on the bigger risks, with the more dangerous consequences.Worrying about the tiny risks of a vaccine instead of the much larger risk from the disease is kind of like someone constantly watching the sky because they're worried about being hit by an aircraft... and wandering into the path of a car instead.

Here's some food for thought:

• One in every 300 babies who receive a vaccination against diphtheria, tetanus and whooping cough (pertussis) will suffer from a period of inconsolable crying.
• One in every 10 babies infected by diphtheria will die.
  Two in every 10 babies under a year of age infected by pertussis will get so sick they must be hospitalized. And one in every 400 of those hospitalized babies will die.

Evaluating risk by the numbers…

Here's a look at the risks from the disease versus the risks from the vaccine. (Want to know more? This table of figures from the Canadian Pediatric Society spells it all out for you: Summary of diseases and vaccines in Canada (PDF).)