There are many commercial vaccines available to protect cattle against infectious agents. Some are modified-live vaccines, and others are killed products. It’s not always easy to decide which ones are best when vaccinating calves. Russ Daly, DVM, South Dakota State University, says some vaccines have to be modified-live, such as intranasal vaccines. “You don’t have a choice, because there are no killed intranasal vaccines.
If you are giving toxoids like 7-way or 8-way clostridial vaccines (or C. perfringens C and D toxoid), there are only killed vaccines, Where we do have a choice is for viral diseases like IBR, BVD, BRSV or PI-3. There are some killed and some modified-live vaccines for those. For bacterial pneumonia, and pathogens like mannheimia and pasteurella, there are some live versions of those vaccines as well as killed,” says Daly.
Vaccines may contain either living or killed organisms or purified antigens from these organisms. Vaccines containing living organisms tend to trigger the best protective responses. Killed organisms or purified antigens may be less immunogenic than living ones because they are unable to grow and spread in the host. Thus, they are less likely to stimulate the immune system in an optimal fashion. On the other hand, they are often less expensive and may be safer. Living viruses from vaccines, for example, infect host cells and grow briefly. The infected cells then process the viral antigens, triggering a response dominated by cytotoxic T cells, a type 1 response. Killed organisms and purified antigens, in contrast, commonly stimulate responses dominated by antibodies, a type 2 response.
This type of response may not generate optimal protection against some organisms. As a result, vaccines that contain killed organisms or purified antigens usually require the use of adjuvants to maximize their effectiveness. Adjuvants may, however, cause local inflammation, and multiple doses or high doses of antigen increase the risks of producing hypersensitivity reactions. Killed vaccines should resemble the living organisms as closely as possible. Chemical inactivation should cause minimal change to their antigens. Compounds used in this way include formaldehyde, ethylene oxide, ethyleneimine, acetylethyleneimine, and beta-propiolactone.
Features of Modified Live Vaccine For Cattle
IBR, BVD Types I and II, PI3, BRSV and Mannheimia haemolytica. Give 2 ml SQ. Safe for pregnant cows, or calves nursing pregnant cows, providing they were vaccinated pre-breeding, according to label directions, with Pyramid 5 or Pyramid 10. Calves vaccinated before 6 months of age should be revaccinated at 6 months of age. Annual booster is recommended. Modified live, requires mixing.
Benefits of Modified Live Vaccine For Cattle
- A strong, long-lasting immune response that is achieved with fewer doses;
- Adjuvants (immune stimulators) are not as necessary;
- Virus vaccines may quickly stimulate non-specific, antiviral protection via interferon production;
- The quality of the immune response that is stimulated can be different in ways that are currently thought to provide better protection. The details of these differences, however, are too complex to be presented here;
- Less chance of allergic reactions; and,
- The bacteria or virus may look and behave more like the disease-causing form of the organism.
Prices of Modified Live Vaccine For Cattle
$38.79 – $175.49