Vaccinating Animals is Important
What are vaccines and their response?
Vaccines are nothing but bacteria / virus or their components and in some cases, even toxins produced by the bacteria are also used to immunize animals. Protein parts of the bacteria are able to cause stimulation of animal body to produce antibodies hence these components are also called commonly ‘antigens; and the chemical these produce when injected in body are termed ‘antibodies. These antibodies in fact fight future infection hence even if animal is exposed to same bacteria / virus or antigen it does not suffer from the disease.
Age of First Vaccination
As far as ruminant young ones are concerned these become immune- competent (that means will react to and produce antibodies when exposed to an antigen) at embryonal age of around 150 days. Researchers have proved this by injecting antigens when embryo in uterus was around that age and could observer antibody response. But, normally in cows since maternal and foetal membranes have three layers of separation, hence foetus is totally insulated from maternal circulation and no antigen can pass through. In case of human and other animals however smaller proteins / antigens can pass through placenta hence at the time of birth a child has antibodies circulating in blood. In contrast in calves, at birth there are no antibodies in blood. Colostrum, that is first three day’s milk after calving is rich in antibodies. When antibodies-rich colostrum is fed to calves within 6-12 hours of birth antibodies pass thorough intestine intact into circulation and provide protection to calves against diseases at least for few more weeks till the time calves are exposed to antigens and are able to produce active antibodies.
Should vaccination be done when animal is suspected to be sick with same or other disease?
No, never do that, as it may increase severity of the disease. If there is already an outbreak of the disease in the farm, decision of vaccinating other animals in the farm should be taken in consultation with a qualified veterinarian. A practical approach is to separate animals that are showing even early signs of the disease and those without signs but showing fever (if fever is one of the symptoms) should be separated and treated but not vaccinated. Whereas, healthy animals can be vaccinated and separated from diseased animals. Even vaccinated animals should be kept under observation because these might be in early incubation period and might show symptoms at later stage.
What about vaccinating animals when there is an outbreak in an area?
Some diseases spread rapidly hence when there is an outbreak of such a disease larger adjoining population should be vaccinated. The factor to consider here is how this disease is transmitted, by animal-to-animal contact, animal-to-human contact, by air, by water and the normal animal movement pattern in the area. Such decisions are usually taken by public policy veterinarians. Farmers are expected to and must comply with such instructions since these are in the interest of the farmers and their animals.
Can vaccination be given to pregnant animals?
This is commonly asked question. The answer is yes unless the animal is in sufficient advanced pregnancy and in process of calving. I have vaccinated cows up to 9 months in pregnancy without any problem (unless there is specific direction not to vaccinated in pregnant animals, especially bacteria / viruses known to cause abortion). I prefer vaccinating pregnant animals twice during pregnancy to ensure that colostrum is rich in antibodies. This can be practiced for more-prevalent diseases, such as, colibacillosis in calves. When repeated vaccinations with same antigen is done the process is called hyper-immunization. This procedure is followed when colostrum and later on milk is required to be rich in particular antibodies (such as Hylecobacter pylori, Salmonella tphi, etc.). Colostrum and milk from such hyperimmunized cows is called Health colostrum or Health milk and indicated as supplement in specific disease.
Can vaccination and administration of antibodies and antibiotic be done at the same time?
Can multiple vaccination be done at the same time?
In fact, this should be avoided because the antibody response will also be divided and hence against each antigen response will poorer as compared to when single antigen vaccination is done.