Vaccines are held to the highest standard of safety. The United States
currently has the safest, most effective vaccine supply in history. Years of
testing are required by law before a vaccine can be licensed. Once in use,
vaccines are continually monitored for safety and efficacy.
Each person is unique and may react differently to immunization.
Each year during flu season, at least one in every 20 people in the U.S. will come down with influenza or flu. Some years, that number can be as high as one in every five. For most of us, getting the flu means several days of feeling pretty miserable. Headaches, body aches, fever, chills, fatigue, and exhaustion are all part of the disease running its course. But then most people recover on their own.
But there are some people -- primarily young children, older adults, and people with chronic health...
Occasionally, people who receive a vaccine do not respond to it and may
still get the illness the vaccine was meant to protect them against.
In most cases, vaccines are effective and cause no side effects, or only
mild reactions such as fever or soreness at the injection site.
Very rarely, people experience more serious side effects, like allergic
reactions. Be sure to tell your health care provider if you have health
problems or known allergies to medications or food.
Severe reactions to vaccines occur so rarely that the risk is difficult to
The Centers for Disease Control and Prevention (CDC) and the Food and Drug
Administration (FDA) continually work to make already safe vaccines even safer.
In the rare event that a child is injured by a vaccine, he or she may be
compensated through the National Vaccine Injury Compensation Program (VICP).
For more information about VICP visit http://www.hrsa.gov/osp/vicp/
or call 1-800-338-2382.
Not vaccinating your child? Be aware of the risks.
Immunizations, like any medication, can cause side effects. However, a
decision not to immunize a child also involves risk. It is a decision to put
the child and others who come into contact with him or her at risk of
contracting a disease that could be dangerous or deadly. Consider measles. One
out of 30 children with measles gets pneumonia. For every 1,000 children who
get the disease, one or two will die from it. Thanks to vaccines, we have few
cases of measles in the U.S. today. However, the disease is extremely
contagious and each year dozens of cases are imported from abroad into the
U.S., threatening the health of people who have not been vaccinated and those
for whom the vaccine was not effective. Unvaccinated children are also at risk
from meningitis (swelling of the lining of the brain) caused by Hib (a severe
bacterial infection), bloodstream infections caused by pneumococcus, deafness
caused by mumps, and liver cancer caused by hepatitis B virus.
Are vaccines tested and monitored for safety?
Yes. Before vaccines are licensed, the FDA requires they be extensively
tested to ensure safety. This process can take 10 years or longer. Once a
vaccine is in use, the CDC and FDA monitor its side effects through the Vaccine
Adverse Event Reporting System (VAERS). Any hint of a problem with a vaccine
prompts further investigations by the CDC and FDA. If researchers find a
vaccine may be causing a side effect, the CDC and FDA will initiate actions
appropriate to the nature of the problem. This may include the changing of
vaccine labels or packaging, distributing safety alerts, inspecting
manufacturers' facilities and records, withdrawing recommendations for the use
of the vaccine, or revoking the vaccine's license. For more information about
VAERS, visit www.vaers.org or call the toll-free VAERS information line at
For a quick reference sheet on key vaccine safety elements, an explanation
of VAERS, and "what happens when rare, adverse events are detected?",
consult the Surveillance and Vaccine Safety fact sheet.