Vaccines are a powerful tool in the disease prevention toolbox, but their effectiveness depends a lot on how and when they are used.

Jan Gawthrop, veterinarian and calf grower from North Manchester, Ind., shared tips for increasing vaccine effectiveness at the 2010 Dairy Calf and Heifer Association conference in Lexington, Ky.

Gawthrop began with the reminder that all vaccines work. They have been tested thoroughly for safety and effectiveness. However, vaccines work best in healthy, well-fed, well-rested, mature cattle. Unfortunately, in the real world we do not always give vaccines to animals that fit that description. As a result, there are situations where vaccines do not meet our expectations.

The following are Gawthrop’s tips for getting the most out of vaccines:

  • Read vaccine labels. Labels specify the age and species of animal in which the vaccine is to be used, recommend boosters if needed, describe storage conditions, and list the expiration date, warnings, and withdrawal times. Claims on the label have been tested according to USDA guidelines.
  • Newborn calves can respond to some vaccines. The safety and effectiveness of a vaccine in a specific situation may not have been tested under USDA guidelines (so it can’t be written on the label), but the testing may have been done by practicing veterinarians and their clients.
  • Vaccines often work best when a second dose is given two to four weeks after the first. These booster doses provide maximum immunity for young and naïve animals, and when heavy exposure to a disease organism is expected.
  • Vaccines require energy. Calves with poor nutrition due to shipping, drought, poor mineral supplementation, heavy parasitism, or simply not feeding adequate calories will not build as much immunity following vaccination as those with adequate nutrition.
  • Vaccines are not stress-free. Vaccines sometimes create fever and produce chemical compounds that reduce appetite, and some killed vaccines contain bacterial toxins that must be cleared from the body. Multiple vaccines in one day can mean lots of negative effects that lessen the animal’s ability to respond optimally to each vaccine. Stress from outside events, such as shipping, handling, surgery, diet change, comingling, and adverse weather, also inhibits the immune system and prevents a thorough response to vaccination.
  • Sick animals cannot respond as they should to vaccination. The immune system is already working hard on this challenge, and there may already be bacterial toxins in the body. Appetite also may be reduced, resulting in a negative plane of nutrition.
  • Vaccine companies go to great lengths to deliver sterile, potent, reliable products to you. Handle and store them according to the label. Resist buying a year’s supply to get a deal. Use sterile needles; a needle used once for an injection is no longer a sterile needle. Also, plan what vaccine is needed, and open only that number of doses that day.

Source: Dairy Calf and Heifer Association