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Livestock Vaccines: How They Work and How to Ensure They Do Their Job

Updated September 08, 2021
Russ Daly

Russ Daly

Professor, SDSU Extension Veterinarian, State Public Health Veterinarian

Written collaboratively by Russ Daly and Ann Price.

Vaccines are suspensions of microorganisms administered with the goal of stimulating the body’s immune system against these same organisms, thereby preventing a clinical disease or reducing its severity. The microorganisms included in vaccines are inactivated or modified such that they are not able to cause clinical illness in the vaccinated animal.