To be effective, vaccines must be properly stored and handled. When in doubt, do what it states on the label, says Dr. Chris Clark, an associate professor at the Western College of Veterinary Medicine (WCVM), University of Saskatchewan. It s always important to follow the label directions, because there are no absolute generalities about vaccines and their use.
Most vaccines must be kept cool. Dr. John Campbell, a professor at WCVM, says it s crucial to store modified-live vaccines in appropriately refrigerated conditions. Check the refrigerator periodically to make sure it stays at the proper temperature.
Several studies have shown that temperature in many refrigerators is not ideal for vaccines. In a University of Idaho study, only 33.3 per cent of 129 ranchers refrigerators were functioning properly. Many refrigerators are a little warmer or colder than ideal temperature. This may not matter for keeping food cool for short periods, but could be disastrous when storing vaccine. The Idaho study also looked at vaccine storage at the retail level and only 34 per cent of the 43 suppliers they checked had refrigerators that were functioning properly 95 per cent of the time. University of Arizona studies found more than 76 per cent of the refrigerators tested (at ranches, veterinary clinics and retail outlets) were unacceptable for storing animal health products.
Check the temperature inside your refrigerator to make sure it s within proper range. If you re using an older refrigerator out in the barn to store vaccine, it may be keeping things too cold or not cold enough.
Temperature can be one of the big issues in veterinary practices and supply stores, says Clark. They re supposed to have a thermometer in the refrigerator and periodically take readings to make sure they are within the proper temperature range.
Refrigeration of vaccines is necessary, and it is important to take this seriously. There s no point in buying $200 worth of vaccine at your local veterinary practice or farm store and then put it on the seat of your pickup. You re just throwing your money away. Bring a cooler and ice pack, especially if it s a warm day and you might be running errands before you get home, says Clark.
It s also important to keep vaccine cool out at the chute when working cattle. You spend a lot of money for vaccine, so don t ruin it by allowing it to get too warm, he says. Keep it in the cooler with an ice pack, in the shade, with the lid on to keep it out of direct sunlight.
There are several types of vaccines mainly live vaccines and killed (inactivated) products. In general, killed vaccines are more resilient, and not as fragile. For instance blackleg vaccines can tolerate a little abuse (such as warmer temperatures) and still be effective. By contrast, most modified-live vaccines come as a powder that you mix with liquid just before use and use them up quickly. Not all of them are this way; the anthrax vaccine is a live vaccine that comes as a liquid, explains Clark.
You need to be much more careful with live vaccines than the killed products. The ones you mix before use need to be used up quickly. Once you ve mixed those, the clock is ticking. The label will tell you how long you ve got before they are no longer effective, says Clark.
Don t start the day by mixing every batch of vaccine you ll be using or the doses you inject later in the day won t be any good. Mix according to need, he explains. And if you get done and still have 20 doses left in the vial, throw that vial away; it won t be any good by tomorrow morning when you start working cattle again.
Campbell says it is very important to mix only the amount you ll use within one hour, and to use a new, clean needle when mixing it or drawing it out of the bottle. When adding diluent, make sure the product is then well shaken before use, he says.
We have seen IBR breaks generally in a feedlot situation when people mix up too much ahead of time or take a break and leave the vaccine in the heat for too long before using it up, says Campbell. He recalls one instance in which the feedlot crew mixed a large batch of vaccine and took a break before they finished using it, leaving the vaccine in the processing barn under a heater. The animals vaccinated after they came back to finish the job did not receive any protection. Most vaccines are also light-sensitive, so keep them out of the sunlight.
Modified-live vaccines have just a small amount of antigen or altered virus. This tiny amount has to multiply within the animal to stimulate the immune system to develop immunity. This means that more care must be taken with these live vaccines than with killed vaccines. If a live vaccine is exposed to heat and sunlight, you may kill that little bit of live virus and the vaccine will be ineffective, explains Campbell.
For these reasons it s wise to buy modified-live vaccines in small bottles, so you can be sure to use them up before they are no longer effective. Often they come in bottles of 50, 20 and 10 doses. If you need 100 doses, there s often value in buying a 50, two 20s and a 10, suggests Clark.
When vaccinating cattle, use very clean needles and syringes, especially with live vaccines. If you use a dirty syringe that might have penicillin residue or traces of some other vaccine, this will inactivate live vaccine. If you use multi-dose syringes, they must be scrubbed and cleaned in the most extreme way possible before being used again, he says.
You cannot use any kind of detergent or disinfectant when cleaning syringes, if you plan to use them for live virus vaccines. After scrubbing them, flush with large volumes of clean hot water, and let them thoroughly air-dry before you use them, says Clark. There should be no moisture residue of any kind.
With killed vaccines, it s not quite as crucial. With live vaccines, however, I am torn between the practicality of using a multi-dose gun and using a disposable single-use syringe. You know the latter is clean and sterile when you start. Do not re-sterilize, wash or boil these syringes and needles. They are not that expensive. It s best to use new ones, he says.
When vaccinating cattle, follow all the beef quality guidelines. Inject into the neck, and no other locations. Change needles periodically, to make sure your needle is always clean and sharp, says Clark. A sharp needle goes in easier, with less pain, and causes less tissue damage.
Disposable needles are designed for single use and become dull quickly. If you have trouble pushing it through the skin, or it seems to be snagging as it s coming back out, it s time to change needles. If you drop it, don t wipe it on your jeans and keep using it. It will be dulled and dirty; get a new needle, he says.
Route of administration is also important. If the label says to give it in the muscle, inject it into muscle. If it says subcutaneous, put it under the skin. It won t be as effective if you give it in the wrong place. Drug companies have spent millions of dollars developing vaccines and finding out how to get them to work best. So read the label and follow directions, he says.
Check expiration dates
This is something the supplier should be doing. The product might also have been sitting in your refrigerator a long time, says Clark. Check the date before using it, especially if it was left over from last year.
Think twice before you buy a large batch because it s on sale. You may not want to keep it a long time; it might be safer to buy a new batch for your next cattle working six months from now. You don t want it expiring about the time you use it. Even though you might like to stockpile some products so you always have them on hand, if you keep them for a long time especially the more delicate vaccines they may get too old.
You ll never get the drug companies to give a straight answer on how long the vaccine might be good. These products don t become ineffective overnight when the expiration date occurs. But they are only guaranteed up until that point. They are probably fine to use a few weeks beyond that date, but you wouldn t want to use vaccine that s a year past its expiration date, says Clark.
Also remember that if you are not storing it at proper temperature the shelf life will be much shorter; effectiveness may be gone before the expiration date.
Be careful when handling vaccines, syringes and needles, and try to avoid injecting yourself by accident. You won t get the disease but you can get a nasty reaction to some of the vaccines, says Clark. Your hand or finger may swell and hurt for several days.
Some of the adjuvants (additives that help stimulate the immune system to respond to the antigen in the vaccine), particularly in the killed products, can be quite irritating. If you ve accidentally injected yourself and experience a lot of reaction, seek medical advice. Take the insert from the vaccine with you when you go to the doctor. The doctor can phone the company and speak to their technical services person and ask about that product, to know whether to be worried.
Accidents sometimes happen in spite of best efforts to be careful. The one that really worries people is anthrax vaccine. You won t drop dead if you accidentally inject yourself, but do contact your doctor if this ever happens, he says.
Caution when using anthrax vaccine
With the excess spring moisture in recent years many stockmen are thinking about vaccinating for anthrax.
Keep in mind that with anthrax, because it s a live bacterial vaccine, you cannot administer any kind of antibiotic within two weeks of vaccination (prior to or following the vaccination), says Clark. The antibiotic would kill the vaccine and prevent it from stimulating an immune response in the animal.
If you have a cow with foot rot at the time you re vaccinating, you should probably treat the foot rot because that s an immediate problem, but it s pointless to give her anthrax vaccine that day. You can do a catchup vaccination two weeks later, and then she will be protected. If cattle are coming through the chute and you see a problem that needs treatment, you generally give an injection of antibiotic at the same time because this is the practical thing to do but not when giving anthrax vaccination, he explains.
This is not a problem with other vaccines; you can administer antibiotics at the same time if needed. We don t use any other live bacterial vaccines. Antibiotics won t adversely affect the efficacy of killed vaccines, says Clark. The live viral vaccines are also not an issue. Viruses are not affected by antibiotics. If you re giving a clostridial vaccine (7-way or 8-way) or a respiratory viral vaccine like IBRBVD, there s no problem in treating the animal at the same time with antibiotics. Anthrax is the only vaccine that has this precaution.