Most vaccine-preventable diseases are caused by germs that are called “viruses” or “bacteria.” Vaccines to help prevent these diseases generally contain weakened or killed viruses or bacteria specific to the disease. Vaccines help your body recognize and fight these germs and protect you each time you come in contact with someone who is sick with any of these diseases.

There are a series of steps that your body goes through in fighting these diseases:

First – A vaccine is given by a shot (influenza vaccine may be given by a nasal spray).  

Next – Over the next few weeks the body makes antibodies and memory cells against the weakened or dead germs in the vaccine.

Then – The antibodies can fight the real disease germs if the person is exposed to the germs and they invade the body. The antibodies will help destroy the germs and the person will not become ill.   

Finally – Antibodies and memory cells stay on guard in the body for years after the vaccination to safeguard it from the real disease germs.

Most vaccines are given to babies and young children, but some are needed throughout your lifetime to make sure you stay protected. This protection is called immunity. Vaccines are an important and safe way to keep you healthy.

ALERT:
What should be done if someone has a reaction to a vaccine?

Call a doctor. If the person is having a severe reaction take him or her to a doctor right away.

Call 911 if the person is having difficulty breathing and/or has a change in consciousness.

After any reaction, tell your doctor what happened, the date and time it happened, and when the vaccination was given. 

Ask your doctor, nurse, or health department to file a Vaccine Adverse Event Reporting System (VAERS) form, or call VAERS yourself at 1-800-822-7967.