Date of this Version
Presented at Range Beef Cow Symposium XXII, November 29, 30, and December 1, 2011, Mitchell, Nebraska. Sponsored by Cooperative Extension Services and the Animal Science Departments of the University of Wyoming, Colorado State University, South Dakota State University, and the University of Nebraska–Lincoln.
The use of vaccines and vaccination in general can be a very confusing topic. There are literally hundreds of different vaccines available for use by beef producers, with multiple antigens and differing levels of effectiveness and safety. Veterinarians serve a critical function in making proper recommendations based on individual herd objectives and assessment of risk of exposure and economic loss. However, there is a lack of objective peer reviewed literature to assist the practitioner and beef producer in this area. The purpose of this paper is to bring some sense of philosophy, science and logic to this topic. Management keys to enhancing response to vaccination would be:
1. A genetic base that enhances transfer of colostral immunity and reduces stress.
2. Calving and handling livestock during times of decreased environmental stress.
3. Meeting nutritional demands for the cow during pregnancy and for the calf during periods of higher stress.
4. Handling all livestock with a keen practical knowledge of low stress handling techniques.
5. Reducing exposure to pathogens from outside sources or what we would call biosecurity measures.
There are 3 questions to be addressed as to whether to vaccinate or not.
1. Is vaccination necessary, in other words is there a reasonable expectation of exposure or economic loss associated with a specific organism? A corollary to this may be the cost of vaccination insurance is so minimal that leaving it out during normal herd working events does not make sense.
2. If the vaccination is necessary, is there a vaccine that has been demonstrated to be effective? Depending on the risk of exposure and the perceived economic risk an additional thought process that takes place. That is, the level of effectiveness or protection desired. There is the highest protection available in a vaccine, or the best, there is a level that is less than the highest protection or < best and finally there is a lower protection, or better than nothing. An example of this is the use of a killed BVDV vaccine to protect pregnant cows from the consequences of BVDV exposure. Modified live virus vaccines have been shown to provide superior levels of protection than have the killed virus vaccines. This decision would then be using the best vs. better than nothing depending on herd working events and the opportunities for booster doses.
3. Finally, are the vaccines safe to use in all classes and ages of cattle? Do they create minimum tissue reactions and rare systemic vaccine reactions. Vaccines with adjuvants will cause some level of tissue reactivity and repeated doses will increase the tissue damage. Also, although rare vaccines may cause hypersensitivity reactions.