Overview
What are immunizations?
Immunizations help keep you and your child from getting certain diseases that can be spread to other people (infectious diseases). They also help reduce the spread of disease to others and prevent epidemics. Immunizations are also called vaccines or vaccinations.
If you get a vaccine, it may not completely prevent you from getting a disease. But it does make it much less likely. If you get a disease even after you have been vaccinated, it usually will be just a mild case.
Vaccines are most often given as a shot (injection). Some are given by mouth as a pill or liquid. Others may be given as a spray (aerosol) into the nose.
What are some reasons to get immunized?
Immunizations save lives. They are the best way to help protect you or your child from getting certain diseases that can be spread to other people (infectious diseases). And there are often no medical treatments for these diseases.
They also help reduce the spread of disease to others to prevent sudden outbreaks of the disease, called epidemics. Preventing the spread of disease is very important for people with weak immune systems. These people may not be able to get vaccines, or vaccines don't work well for them. Their only protection is for others to get vaccinated so illnesses are less common.
Other reasons why vaccines are important:
- They cost less than getting treated for the disease.
- The risk of getting a disease is much greater than the risk of having a serious reaction to the vaccine.
- They are often needed for entrance into school or day care. And you may need them for your job or to travel to another country.
What are the side effects of vaccines?
Most side effects from vaccines are minor, if they occur at all. They may include:
- Redness, mild swelling, or soreness where the shot was given.
- A slight fever.
- Drowsiness, crankiness, and poor appetite.
- A mild rash 7 to 14 days after chickenpox or measles-mumps-rubella shots.
- Temporary joint pain after a measles-mumps-rubella shot.
Ask your doctor or pharmacist about other reactions that could occur. Serious reactions, such as trouble breathing or a high fever, are rare.
If you or your child has an unusual reaction, call your doctor. It's much more dangerous to risk getting the diseases than to risk having a serious reaction to the vaccines.
How safe are vaccines?
Vaccines are safe. The U.S. Food and Drug Administration (FDA) carefully evaluates all vaccines for safety. 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.
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 unvaccinated children may die from diphtheria disease. But only 1 child in a group of 14,000 vaccinated children may have convulsions or shock after getting the DTaP vaccine. And that child would recover fully.footnote 1