“That’s why it’s even more important not to overload cattle with gram-negative vaccines in the heat of summer,” cautions Davidson. “Unfortunately, we are not able to predict which animals are more sensitive to the effects of heat stress and LPS endotoxin. However, we do know that certain weather conditions and vaccines containing whole cells of target bacteria can increase the likelihood of an unfavorable response.”
Fortunately, newer vaccine manufacturing processes enable us to minimize the inclusion of the endotoxin or LPS-containing portions of the bacterial cell wall. A good example is NUPLURA® PH, the newest M. haemolytica vaccine to enter the U.S. marketplace. NUPLURA PH is not a traditional “whole-cell” vaccine. It’s unique in that its principle components are outer protein membranes (OMPs) that have been extracted and purified.
These OMPs are joined by a recombinant leukotoxoid and an adjuvant. This production process reduces the amount of the whole-cell wall present in the vaccine and, therefore, lowers the potential for a reaction to LPS endotoxin.
“To get the maximum response from vaccines, it’s important that we don’t overwhelm the animal’s immune system,” Davidson says. “In the summertime, this means avoiding working cattle if the temperature is above 85 degrees F with humidity above 40%, or at higher temperatures with lower humidity.”2
To maximize the effectiveness of your vaccination program:
- Always consult with your veterinarian regarding vaccination protocols as part of your herd’s total health program.
- Properly store products.
- Vaccinate healthy animals.
- Administer vaccines using good hygiene and according to label directions.
- Understand there’s a higher potential for adverse reactions in hot weather and high humidity. Keep proper treatments on hand, like epinephrine, to quickly address any adverse animal reaction.
- Use these heat stress guidelines and the accompanying temperature-humidity index chart from the Kansas Department of Agriculture to reduce the effects of heat stress.
Keep in mind that making good vaccine choices is only one part of preventing costly diseases in cattle. Good nutrition is the cornerstone of animal health management and along, with mineral supplementation, is essential for vaccine efficacy.
1Lambert GP. Stress-induced gastrointestinal barrier dysfunction and its inflammatory effects. J of Animal Sci. 2009; 87:E101-E108.
2Bagley C. Vaccination Program for Beef Calves. Accessed June 11, 2012.