Education and Community Resources

What is Immunity and Why is it Important?

A body builds immunity to a virus or bacteria by being exposed to it. People build immunity to viruses and bacteria of all kinds throughout their lives, many times through exposure via daily life.

Human bodies, however, are not able to build natural immunity to all bacteria and viruses that are encountered in life. Though the first vaccine was developed in 1796, medical science advanced significantly in the 1940s, 1950s and 1960s when vaccines for a number of very common — and often deadly or debilitating — diseases were affecting the mass population.

When a person receives a vaccine, their body begins building immunity to protect it from a potential invasion of a particular virus. Vaccines contain a modified form of a virus or bacteria that does not cause disease, but does “teach” your immune system what to do if you are ever attacked by the real virus or bacteria.

The Centers for Disease Control and Prevention offers a more in-depth definition of immunity and the way vaccines work.

Immunity from transmittable diseases is important to both individuals and to the community at-large.

Community Resources About Immunity and Vaccinations:

Michigan Department of Health and Human Services

St. Clair County Health Department

Centers for Disease Control and Prevention