group photo of adults, teens and babies
How Vaccines Prevent Disease
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:
  • First - a vaccine is given by a shot (influenza vaccine may be given by a nasal spray and rotavirus vaccine is given by mouth). 
  • Next - over the next few weeks your 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 you are exposed to the germs and they invade your body. The antibodies will help destroy the germs and you will not become ill.
  • Finally - antibodies and memory cells stay on guard in your body for years after vaccination to safeguard you 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. 

Are HPV vaccines safe? How is the safety of HPV vaccines monitored and evaluated in the United States? Find the answers to these and other important HPV vaccine safety-related questions at

Do I Need Any Vaccines Today? Answer these few questions, to see which vaccines you may need
Shingles (Herpes Zoster) 

Vaccine Information Statements are available in numerous different languages from the Immunization Action Coalition
Where To Find Your Vaccination Records
Educational Materials (DPH Immunizations) Fillable pdf
Immunization for Women Web Site The American College of Obstetricians and Gynecologists' immunization web page, Immunization for Women, is an excellent resource for health care providers and patients to find up-to-date information about immunizations and vaccine-preventable diseases.
Parents Guide to Childhood Immunizations                    

For more information or to contact the Immunization Program, please call:
860-509-7929, during normal business hours, Monday-Friday 8:30am to 4:30pm


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