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Because vaccines must be safe for use by as many people as possible, vaccines are developed in accordance with the highest standards of safety. Years of testing are required by law before a vaccine is licensed and distributed. Once in use, vaccines are continually monitored for safety and efficacy.

However, as with any medical procedure, vaccination has some risks despite the substantial, proven benefits. Individuals react differently to vaccines, and there is no way to absolutely predict the reaction of a specific individual to a particular vaccine. There may also be some religious or ethical considerations to weigh. Anyone who takes a vaccine should be informed about both the benefits and any potential risks or issues with vaccination.

Below are various vaccine safety topics in alphabetical order. Click on the links to learn more, and please contact us if you have any additional questions or concerns.

Autism and vaccines

General information about vaccines

Ingredients in vaccines

Multiple vaccinations and immune system

Religious and ethical considerations

Additional resources on vaccine safety

Book and pamphlets:

  • Do Vaccines Cause That? A Guide for Evaluating Vaccine Safety Concerns, Myers, Martin G. MD and Diego Pineda.
  • What to Expect Guide to Immunizations, Murkoff, Heidi. New York : The What to Expect Foundation, 2008.
  • Vaccines: What You Should Know, Offit, Paul A. MD and Louis M. Bell, MD.  3rd edition.  New York : Simon & Schuster, March 2003.
  • Plain Talk About Childhood Immunizations, Public Health - Seattle & King County and Snohomish Health District. Available free from Within Reach at 1-800-322-2588 (voice) or 1-800-833-6388 (TTY), and from Washington State Department of Health at (360) 664-2929 (fax only).


Email, fax and phone numbers:

  • LOCAL: Public Health - Seattle & King County
    • Immunization Program: 206-296-4774
    • Vaccine Distribution Program: 206-296-4782
    • Communicable Disease Hotline: 206-296-4949
    • Email:

  • STATE: Washington State Immunization Program:
    • Main number: 360-236-3595

  • FEDERAL: Centers for Disease Control and Prevention (CDC)
    • National Immunization Program e-mail address:
    • Telephone consultation: CDC-INFO Contact Center, staffed 8 am-11pm (EST)
    • English and Spanish: 1-800-CDC-INFO (800-232-4636)
    • CDC Fax Information Service: 1-888-CDC-FAXX (1-888-232-3299)