Preventing Disease Through Immunization

A person receiving a shot in the upper arm.

Immunization is the action of developing a lower risk of getting a disease due to improvements in the body's disease-fighting system (immune system). Immunization can happen through:

Natural exposure to a disease.
Getting shots (vaccination).

Vaccination involves putting a small amount of dead or weakened germs (vaccines) into the body. This may be done through one or more shots. Some vaccines can be given by mouth or as a nasal spray instead of through a shot. Vaccination helps to prevent:

Serious diseases such as polio, measles, and whooping cough.
Common infections, such as the flu.

Vaccination starts at birth. Teens and adults also need vaccines regularly. Talk with your health care provider about the immunization schedule that is best for you. Some vaccines need to be repeated when you are older.

How does immunization prevent disease?

Immunization occurs when the body is exposed to germs that cause a certain disease. The body responds to this exposure by forming certain proteins, called antibodies, to fight those germs. Germs in vaccines are dead or very weak, so they will not make you sick. However, the antibodies that your body makes will stay in your body for a long time. This improves the ability of your immune system to fight the germs in the future. If you get exposed to the germs again, your body may be able to resist them because you have developed immunity against them. This is because your antibodies may destroy the germs before you get sick.

Why should I prevent diseases through vaccination?

Vaccines can protect you from getting diseases that can cause harmful complications and even death. Getting vaccinated also helps to keep other people healthy. If you are vaccinated, you are less likely to spread disease to others, and that can make the disease become less common. If people keep getting vaccinated, certain diseases may become rare or go away. If people stop getting vaccinated, certain diseases could become more common.

Not everyone can get a vaccine. Very young babies, people who are very sick, or older people may not be able to get vaccines. By getting immunized, you help to protect people who are not able to be vaccinated.

Where to find more information

To learn more about immunization, visit:

World Health Organization: www.who.int
Centers for Disease Control and Prevention: www.cdc.gov/vaccines

Summary

Immunization occurs when the body is exposed to germs that cause a certain disease and responds by forming proteins (antibodies) to fight those germs.
Getting vaccines are a safe and effective way to develop immunity against specific germs and the diseases that they cause.
Talk with your health care provider about your immunization schedule, and stay up to date with all of your vaccinations.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.