A vaccine can cost over $3 a head, and if not stored properly, that vaccine can be rendered ineffective. Producers cannot afford to overlook the importance of how they store vaccine and handle it prior to injection.
Biological products should be stored under refrigeration at 35ºF to 45ºF unless the nature of the product makes storing at a different temperature advisable. If vaccines are not stored within this temperature range, efficacy to the calf can and will be reduced. Killed vaccines are especially susceptible to freezing temperatures. Freezing a killed vaccine will alter the adjuvant or delivery system of a killed vaccine. This, in turn, negatively affects the immune response to the antigen in the vaccine. Modified live viruses (MLV) are more stable but can be inactivated if they are repeatedly cycled above or below the required temperature range. Also, once activated by mixing, MLV’s effective life will be reduced to one to two hours and will need to be maintained at 35ºF to 45ºF. This can be accomplished by only mixing the doses that you will use at that time, and use a cooler to maintain temperature while working cattle.
Researchers from the University of Arkansas and Idaho analyzed the consistency of temperatures for different types, ages and locations of refrigerators over a 48-hour period. They found that only 26.7 percent and 34 percent of refrigerators were within the acceptable temperature limit 95 percent of the time, respectively. Refrigerator location can also affect temperature. Refrigerators located in barns (35.6ºF) were colder than in mudrooms (41.72ºF) and kitchens (40.82ºF). Temperature within a 24-hour period can also be highly variable for individual refrigerators. Researchers demonstrated some refrigerators may take up to eight hours to cool down to the 45ºF required or temperature can drop below freezing and range from 28.4ºF to 44.6ºF, while others will remain too cold, varying from 24.8ºF to 35.6ºF over that period of time.
Producers need to be aware of these variations in temperature so they are able to adjust refrigerator temperature as needed. Thermostats can also vary from unit to unit, so keeping a thermometer inside works well to monitor and to make adjustments as needed. Simple indoor-outdoor thermometers work well to achieve this goal. The outdoor unit can be placed in the refrigerator while the LCD display can be hung with a magnet on the door. This allows temperature to be monitored without opening the door, and many models will record the high and the low temperature in a 24-hour period so producers can adjust accordingly.
How a producer handles vaccine outside of the refrigerator is important as well. Coolers can easily be modified for syringes and are important to maintaining vaccine efficiency chute-side. Using a 1 1/2 inch PVC pipe or sink tail piece purchased at any hardware store and a 1 1/2 inch hole saw, inserts can placed through the cooler and work well to keep syringes cool and out of light while in use. Either ice or freezer packs can be used as a coolant to maintain temperature for several hours depending on outside ambient temperature. Make sure that enough coolant is used to maintain temperature while working cattle, and extra ice may be needed if working cattle all day or during warm days. It may also take up to an hour for the cooler to reach the needed 45ºF, so producers may need to plan ahead prior to processing cattle. Detailed instruction on the construction of a chute-side vaccine cooler is available in this Oklahoma State University article.
These are a few simple suggestions that can help ranchers get the full value of the vaccine that they purchase. More importantly, producers who follow these suggestions could positively affect the health of their herd, decrease sickness and increase profit.
References omitted but are available upon request. Click here to email an editor.
Gant Mourer is a beef value enhancement specialist at Oklahoma State University. This originally appeared in the June 12, 2017, OSU Cow/Calf Corner newsletter.