How Vaccines Work

Vaccine Myths

vaccine lab
Jack Guez/AFP/Getty Images
A French lab is working on the vaccine for the H5N1 virus.

MYTH: Vaccines cause autism.
TRUTH: "Study after study has shown that there is no link between vaccines and autism," says Angie Matthiessen with Children's Healthcare of Atlanta. This myth gained popularity when children were diagnosed with autism around the time that they received the MMR vaccine (around 18 months of age), according to Joyce Allers, RN, also with Children's Healthcare of Atlanta. At the time, the mercury-containing preservative Thimerosol was being put in some vaccines -- although not the MMR vaccine -- to keep bacteria from growing, so many people connected that to autism. However, there still appears to be no link between previous use of Thimerosol and autism. Thimerosol was completely removed from all infant vaccines in the United States in 2001, yet autism rates continue to increase. Thimerosol is currently present only in minute amounts in the influenza vaccine.

There are also Thimerosol-free influenza vaccines.

MYTH: Vaccines aren't necessary anymore because all the diseases are gone anyway.
TRUTH: According to the CDC, if we stopped vaccinating, many diseases that are largely unknown would come back with a vengeance. The only vaccine-preventable disease that's been completely wiped out is smallpox. "These diseases are coming into our country, into our schools and into our workplace," says Matthiessen. "Don't believe that your child is 100 percent protected because the disease isn't currently in the United States. International travel and adoption are two of the ways that dangerous diseases make their way into the country."

The Future of Vaccines
Vaccines are currently being developed for a myriad of diseases, including HIV/AIDS, cancer, the plague and even the common cold. Although it may be years before any of these vaccines make it to pharmacy shelves, their development is critical because as surely as we are able to destroy a particular disease another one is probably just around the corner. A list of potential new vaccines is available here.

MYTH: Babies are too fragile to get so many shots.
TRUTH: "A lot of young parents are worried about giving their babies so many shots, thinking that they will overwhelm their immune system," says Allers. "I tell them that as human beings we are exposed to disease all the time, like at the mall and church, so we can't overwhelm their systems." According to the Children's Hospital of Philadelphia's Vaccine Education Center, diseases often occur in very young infants, so the best way to prevent them is to give vaccines as soon as possible after birth. "We have a wonderful history of eliminating disease, but what worries us is all the good progress we've made is going to be diminished by families choosing their own vaccination schedule or choosing not to vaccinate at all," Allers says.

MYTH: A live vaccine can give me the disease it's supposed to prevent.
TRUTH: As we've discussed, live vaccines can cause extremely mild symptoms. However, experts agree that they are very minor and much better than coming down with the full-blown disease.

For more information on vaccines and related topics, check out the links on the next page.

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More Great Links


  • Allers, Joyce, R.N. Personal interview. 22 Aug. 2007.
  • American Academy of Pediatrics.
  • American History.
  • American Veterinary Medical Association.
  • "A Parent's Guide to Vaccine-Preventable Diseases for Children." Toronto, Ontario, CA: Sanofi Pasteur, 2005.
  • Bradley, John, M.D. Personal interview. 30 Aug. 2007.
  • Centers for Disease Control and Prevention.
  • Children's Hospital of Philadelphia's Vaccine Education Center.
  • Foster, DVM Race; Marty Smith, DVM and Holly Nash, DVM, MS. "Vaccination Recommendations for Dogs." Pet Education. 4 Sept. 2007.
  • Foster, DVM Race; Marty Smith, DVM and Holly Nash, DVM, MS. "Vaccination Recommendations for Cats and Kittens." Pet Education.
    4 Sept. 2007.
  • Many Cases, Real Risks, More Reasons to Protect Yourself. Toronto, Ontario, CA: Sanofi Pasteur, 2006.
  • Immunization Action Coalition.
  • Matthiessen, Angie, MSW. Personal interview. 22 Aug. 2007.
  • Maybury Okonek, Bonnie A. and Pamela M. Peters, Ph.D. "Vaccines: How and Why?" Access Excellence. 25 Aug 2007
  • Malaria Vaccine Initiative.
  • "Measles Deaths Down Worldwide." CNN Online: Health. 19 January 2007. 3 September 2007
  • National Institute of Allergy and Infectious Diseases.
  • Petplace Veterinarians. "Canine Vaccine Recommendations." PetPlace. 4 Sept 07
  • Schaffner, William, M.D. Personal interview. 18 Sept. 2007.
  • "Vaccination Fact vs. Fiction." Philadelphia, PA: Wyeth Pharmaceuticals, Inc., 2005.
  • World Health Organization.