Vaccines stimulate an animal’s immune system without infecting them with the disease. Vaccines help to prevent disease and work best when whole groups or populations of animals are vaccinated.
Vaccines work very differently from antibiotics and anthelmintics. If a vaccinated animal comes into contact with a disease, its immune system will recognise it and immediately produce the antibodies it needs to fight it.
Vaccinations are a wise investment, as outbreaks of disease are often unpredictable and can have major financial implications for a farm business. Losses can occur as deaths, abortions and sick animals. It is often the production losses from subclinical disease that have the greatest financial impact.
There is a wide range of vaccines licensed for use on farm animals in the UK. Increased use of vaccines could help reduce the level of disease and so reduce the need for antibiotics.
Vaccines have very specific storage requirements. All vaccines must be kept refrigerated at all times until they are used. Live vaccines are especially fragile. If they become too hot or are frozen for any length of time, the organisms in the vaccine will be destroyed and the vaccine will not work.
Leaving a live vaccine in a hot vehicle for just 30 minutes is enough to render the vaccine ineffective. Vaccines must be used quickly after the bottle is opened for the first time.
Dosage requirements of vaccines are quite different from other medicines, with a set dose for each class of animal, regardless of weight. Initial vaccination courses often need two doses, with a booster later on to maintain immunity.
Some vaccines are specifically licensed for use in pregnant cows or ewes to increase the level of antibodies in colostrum and to protect the offspring that drink it. It is important to give the vaccine at the recommended time to ensure newborn calves and lambs get enough colostrum.
Other vaccines may not be safe to use in pregnant animals. Some vaccines are affected by levels of maternal antibodies from colostrum and, therefore, these vaccines should not be given too early in life. Always check and follow instructions on the data sheet for each vaccine or ask your vet.
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