Vaccinating calves and heifers is a nearly mandatory procedure to support a healthy and productive lifetime for each animal. But simply delivering the vaccine to the animal is not enough, according to Dr. Amelia Woolums, Professor in the College of Veterinary Medicine at Mississippi State University.
Using vaccines most effectively requires background knowledge in the way vaccines work, the way animals respond, and the particular challenges specific to your herd,” said Woolums. “Only you and your veterinarian can establish the best vaccine protocol for your operation.”
Woolums explained that calves are born with no immune system. Over time, they build natural – or “innate” – immunity, which is not fully developed until about 6 months of age. In the period between, antibodies from colostrum help bridge the immunity gap, which is one of the reasons why timely delivery of quality colostrum in the first hours of life is so important.
“Acquired” immunity is immunity against specific, targeted pathogens which are introduced to the animal’s system via vaccines. Those organisms may be either “killed” in the vaccine, or “modified live,” meaning the pathogen still is alive -- albeit in an altered form that usually does not cause the animal to become clinically ill with the disease.
Some other interesting insights regarding vaccines from Woolums:
- Any vaccine licensed by the USDA has been proven efficacious, but strict adherence to label instructions is required for the intended protection to occur.
- Vaccines that induce inflammation usually produce a stronger immune response. “Inflammation is an innate immune response,” said Woolums. “It helps kick off the acquired immune response when a vaccine is administered.”
- Modified live vaccines must be handled with extreme care in field conditions so as not to destroy the live organism in the vaccine. Average life of that organism after the vaccine is reconstituted is just 1 hour, so plan accordingly when vaccinating large groups of animals.
Woolums added there is a metabolic cost to every vaccine administered, and that it is possible to over-vaccinate animals. “Again, partner with your veterinarian to develop a vaccine protocol that is best for your herd,” she advised.