African American woman getting band aid put on after receiving a vaccine.

How Vaccines Work

Vaccines are an important and safe way to keep you healthy! 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 to develop immunity through vaccination:

Step 1

A vaccine with weakened or killed viruses or bacteria is given by a shot (influenza vaccine may be given by a nasal spray and rotavirus vaccine is given by mouth).

Step 2

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

Step 3

The antibodies can fight the real disease if you are exposed to the germs and they invade your body. The antibodies will help destroy the germs so you won’t get sick.

Step 4

Antibodies and memory cells stay on guard in your body for years after you’re vaccinated to protect you from disease. This protection is called immunity.

Connecticut Vaccine Program (CVP)

All doctors and health care providers in Connecticut who vaccinate children under 19 years of age participate in the Connecticut Vaccine Program (CVP) and can give your child the vaccines he or she needs.

Through the CVP program, the state buys vaccine at the lowest possible price through a government contract and then gives the vaccines at no cost to clinics, private doctors, and other health care providers. These providers then vaccinate children without charging patients for the cost of the vaccine (health care providers may still charge an administration fee). Without this program, some insurance companies may not cover the full cost of vaccine, making it too expensive for some families. If you need help finding a health care provider for your child, call (860) 509-7929 to find a CVP provider near you.

Good For Your Children — Good for Connecticut

The CVP helps make sure that all Connecticut children get the immunizations they need by the age of 2 years old. This is important because serious illness is most likely to happen in the first two years of a child’s life. By getting more children vaccinated against vaccine-preventable diseases, all of which can be serious, we help to improve the health of everyone in Connecticut.


CT WiZ Information for the General Public 

Learn more about Connecticut's Immunization Information System (IIS), CT WiZ, including the benefits, how to enroll, how to get your immunization record and more!

2023-24 CT Influenza Vaccination Clinics 

Not sure where or when to get your flu shot? Learn more about Influenza vaccinations and where you can get a flu shot in CT!

Vaccine Information for General Public 

Learn more about vaccine information by vaccine type, and by the population groups for adults, for parents, for college, for pregnant women, and individuals traveling internationally, and for individuals who moved to CT from Ukraine.