Immunization Safety

Topic Overview

Some people question the safety of immunizations for children. Although minor discomfort sometimes follows vaccine injections, research does not support claims that immunizations put a child at any significant risk for harmful side effects. The U.S. Centers for Disease Control and Prevention (CDC) vaccine information statements list the side effects of each vaccine.

The risk of a serious complication from a disease is far greater than the risk from the vaccine. For example, 1 child in a group of 20 children may die from diphtheria disease. But only 1 child in a group of 14,000 children may have convulsions or shock after getting the DTaP vaccine. And that child would recover fully.^{footnote 1}

The U.S. Food and Drug Administration (FDA) carefully evaluates all vaccines for safety. After a vaccine is approved, the FDA, the CDC, the vaccine maker, and several other agencies watch for any reports of rare or unexpected reactions. Federal law requires health professionals to report any reaction following an immunization to the Vaccine Adverse Events Reporting System (VAERS). For more information about how vaccine safety is checked, see www.cdc.gov/vaccinesafety/index.html.

Immunizations are safe even if your child:

• Currently has or is recovering from a minor illness, such as a cold or an ear infection.
• Has a slight fever.
• Has had recent exposure to someone with a contagious disease.
• Was born early (prematurely).
• Had a mild reaction (such as redness at the site of the injection or a slight fever) from a previous injection.
• Is currently taking antibiotics.
• Has had mild allergies or seizures or has a family history of such problems.
• Has had allergic reactions to penicillin or other antibiotics (except for a history of severe reactions to neomycin or streptomycin).

Immunizations may be given to pregnant women, except for the following:

• Chickenpox (Varicella)
• Human papillomavirus (HPV)
• Measles, mumps, and rubella (MMR)
• Nasal spray flu vaccine
• Smallpox
• Typhoid
• Yellow fever

Safety of multiple vaccines

Some people have voiced concern about immunizations when multiple vaccines for different diseases are given at the same time. These people fear that harmful side effects are more likely because the child's immune system is not able to combat all of the vaccine organisms at the same time.

Getting more than one shot (injection) of vaccine at the same time may seem like a lot to handle. But babies have billions of immune system cells in their bodies. Beginning at birth, the immune system actively responds to hundreds of thousands of invading organisms.

After careful study, more and more vaccines are being combined into a single shot, such as the measles-mumps-rubella shot (MMR). Combining vaccines means fewer shots need to be given. In most cases, each vaccine provides the same protection that it would if it had been given alone.^{footnote 2}

The U.S. Advisory Committee on Immunization Practices and the American Academy of Pediatrics both recommend that in one doctor visit a child get all of the vaccines needed at his or her age.

The CDC and the FDA continue to study vaccines. Although the risk of problems from vaccines is already extremely low, these agencies watch for any reports of rare or unexpected reactions.

Talk to your doctor if you have concerns about the safety of immunizations.