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A Parent's Guide to Kids' Vaccines

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Examples of serious reactions include:

• anaphylaxis or severe allergic reaction in persons who are allergic to any vaccine components (ingredients)

• development of temporary arthritis following rubella vaccine

• development of a disease similar to the disease that the vaccine is intended to prevent if a “live-attenuated vaccine” (see below) is given to a person with a weakened immune system

For a more comprehensive list of risks, you should review the package insert or patient information for each vaccine. It is important to discuss with your health care provider any prior reactions to vaccines and any adverse reactions following vaccination.

"However, parents should know that the risk of being harmed by a vaccine is significantly smaller than the risk of serious illness that comes with infectious diseases," says Norman Baylor, Ph.D., director of the Office of Vaccine Research and Review in CBER. "Vaccination is a very important step to get children off to a healthy start."

Types of Vaccines

Vaccines work by triggering a response by the body's immune system when administered. Vaccines stimulate the body to make antibodies—proteins that specifically recognize and target the disease-causing bacteria and viruses, and help eliminate them from the body before they cause disease. Vaccines are frequently given by injection (a shot), but some are given orally and one is given via nasal spray.

There are several types of vaccines: live-attenuated, inactivated (whole or subunit), and toxoids. Live-attenuated vaccines contain a living bacteria or virus that has been weakened in the laboratory so that it doesn't cause the actual disease in individuals with healthy immune systems. However, because they contain a small amount of the weakened live virus or bacteria, they should not be taken by people with incompetent or weakened immune systems. One example of a live attenuated vaccine is the Measles, Mumps and Rubella Virus Vaccine, Live.

Inactivated vaccines can be safely given to individuals with weakened immune systems. However, for such individuals, additional (booster) doses may be required to achieve immunity (protection). One example of a whole inactivated vaccine is the Poliovirus Vaccine Inactivated.

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