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Certain Situations Can Diminish the Effectiveness of Your Vaccination Program

Dairy Pipeline: October 1998

Tom L. Bailey
Dairy Production Medicine
Virginia Maryland Regional College of Veterinary Medicine
Virginia Tech

To ensure you're getting the most benefit from your vaccinations, always work with your veterinarian to formulate a plan for both your youngstock program and your lactating and dry cows. The basis of any well formulated vaccination strategy, is a good foundation program in the replacement heifers. REMEMBER, no vaccine is 100 percent effective. However, we need to control those factors we can, like proper refrigeration and proper administration. The effectiveness of a vaccine can be limited by several factors. Improper storage and temperature, both during shipment and on the farm, can degrade the vaccine. Never mix two vaccines together for administration. Some agents contained in one vaccine may inactivate the product of the second vaccine. Vaccines may also be inactivated by disinfectants used to clean syringes. Use disposable syringes or disassemble the syringe, thoroughly clean, rinse in distilled water and allow the syringe parts to air dry. The effectiveness of a vaccine is also dependent on the response of the animals receiving the vaccination. Animals that are too young, less than 4 months of age, may still carry antibodies (protection against a disease) passed through the colostrum from the dam. These antibodies may deactivate the vaccine. Therefore, re-administration or certainly boosters are important when vaccines are given to animals below 4 or 5 months of age. Boosters are vital to stimulate an adequate response, especially when using killed products, so always follow label directions. Extended waiting periods between boosters will decrease the protection of the animal. Debilitated or unthrifty animals, animals that are sick, or animals already carrying the disease will not respond with adequate protection. Antibiotics or other drugs given at the same time as vaccines may alter the immune response of the respective animal. Always seek the advice of your veterinarian when formulating your vaccination program for information on which vaccinations to use on specific cattle groups, how and where to administer the products, and proper storage and handling techniques.

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