Content added June 25, 2025

Different vaccines work in different ways, but every vaccine helps the body’s immune system learn how to fight germs. It typically takes a few weeks for protection to develop after vaccination, but that protection can last a lifetime. A few vaccines, such as those for tetanus or seasonal flu, require occasional booster doses to maintain the body’s defenses. Immunity is the body’s way of preventing disease. Vaccines can prevent common diseases that used to seriously harm or even kill infants, children, and adults. Without vaccines, your child is at risk of becoming seriously ill or even dying from childhood diseases such as measles and whooping cough.

Before a new vaccine is ever given to people, a lot of lab testing is done. Once testing in people begins, it can still take years before clinical studies are complete, and the vaccine is licensed. After a vaccine is licensed, the Food and Drug Administration (FDA), CDC, National Institutes of Health (NIH), and other federal agencies continue routine monitoring and investigate any potential safety concerns. CDC and the FDA take great care to make sure that a vaccine is safe both before it is licensed and after the public begins using it.

Vaccines, like medicine, can have some side effects. But most people who get vaccinated have only mild side effects or none at all. The most common side effects include fever, tiredness, body aches, and redness, swelling, and tenderness where the shot was given. Mild reactions usually go away on their own within a few days. Serious, long-lasting side effects are extremely rare. We know they are rare because CDC tracks and investigates reports of serious side effects. For additional information about vaccines for children, click here. Reasons to Vaccinate | Childhood Vaccines | CDC. 

Click here for vaccine information for adults. Vaccine Information for Adults | Adult Vaccines | CDC.

You can receive vaccines/immunizations for yourself and your children at your primary care provider’s office. Vaccines are also available at Columbia/Boone County Public Health and Human Services at 701 E. Broadway, 573-874-7249. Vaccines are covered by insurance. Public Health and Human Services has a special program that can pay for vaccines if you do not have insurance. See link below for additional information about vaccines.

Immunizations - City of Columbia Missouri