Storage of vaccines can affect efficacy

News
Jun 27, 2014
by WLJ

Respiratory disease in cattle, also known as BRD, shipping fever or pneumonia, may cost the U.S. cattle industry more than $2 billion annually. Management techniques can offset much of this cost and having a good vaccination program can maintain the health of a calf all the way through the production system. A vaccine can cost more than $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 35-45 degrees Fahrenheit 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 in-activated 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 need to be maintained at the 35- to 45-degree temperature. 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, respectfully. Refrigerator location can also affect temperature. Refrigerators located in barns (35.6 degrees F) were colder than in mudrooms (41.72 degrees F) and kitchens (40.82 degrees F).

Temperature within a 24-hour period can also be highly variable for individual refrigerators. The University of Arkansas and Idaho demonstrated some refrigerators may take up to eight hours to cool down to the 45 degrees F required or temperature can drop below freezing and range from 28.4 to 44.6 degrees, while others will remain too cold varying from 24.8 to 35.6 degrees 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 be very variable from unit to unit, so keeping a thermometer inside works well to monitor and to make adjustments as need. 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 the 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 1.5-foot PVC pipe or sink tail piece purchased at any hardware store and a 1.5-foot 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 45 degrees F, so producers may need to plan ahead prior to processing cattle.

These are a few simple suggestions that can help ranchers get the full value of the vaccine that they purchase, and, more importantly, positively affect the health of their herd, decrease sickness and increase profit. — Gant Mourer, Beef Value Enhancement Specialist, Oklahoma State University

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