Cold and flu season may be waning for the year for humans, but farmers might still give their animals vaccines. Why do they do that?
One of a farmer’s main priorities in raising animals is keeping the animals healthy. Vaccines are one of the tools that farmers use to help keep their animals healthy. First, it is important to understand the difference between vaccines and antibiotics. Antibiotics are used to treat bacterial infections AFTER an animal like a pig or a human have gotten sick. Antibiotics are chemical agents that act by killing the bacteria or preventing the bacteria from multiplying. Vaccines on the other hand are given to animals BEFORE they get sick to try and prevent infection. Vaccines use a dead or modified virus to stimulate the body’s natural defenses against infection without causing the illness itself. If after the immunization, the body is exposed to the specific virus in the future, it will recognize it and fight off the infection much more quickly and effectively.
Once an animal receives a vaccination, the immune system responds by producing antibodies that destroy the infectious agents. This stimulates immunity from contracting the disease in the future. Vaccines are typically used to fight viral diseases but can also be used to immunize against bacteria, bacterial toxins, or parasites. They are usually given to animals in the form of an injection.
Pigs, for example, are communal animals. They love being around and interacting with each other. Modern farms raise pigs in barns and in shared pens. Each pig has a lot of close contact with all of the other pigs. If one pig gets sick, there is a high likelihood that all of the other pigs would get sick too. It is sometimes hard and costly to treat a lot of sick pigs. So preventing illness is the preferred strategy. If all pigs are vaccinated, then they are all safe. Even if one animal doesn’t get vaccinated, it should still be safe because of herd immunity.
There are several diseases that are common in pigs. Procine parvovirus, PRRS, swine fever, and swine influenza are just a couple of examples that vaccinations can help protect against. In part, farmers are trying to manage the health of their animals. But some of these diseases (like swine flu) can be transmitted to humans. Keeping the pigs healthy helps keep humans healthy.
Throughout much of human history, diseases have caused widespread deaths. Smallpox was one of the most feared. In 1774 and English farmer inoculated his wife and sons with puss from a cowpox lesion on one of his cows. The wife and sons couldn’t contract the cowpox, but it was similar enough to smallpox that their bodies developed a resistance to both diseases. This was how the idea of vaccination first started. This inoculation technique was widely used and then by 1796 Edward Jenner had success in research and experimentation with vaccinations. His techniques continued to improve and over the succeeding years were applied to other diseases.
Most piglets receive their first shots of vaccines within a week after they are born. This helps ensure they have a healthy immune system from early on. These early vaccines are for common diseases and can be easily prevented. After the first round of shots, sometimes booster shots are required to ensure the vaccine is effective. Viruses can mutate in nature. Influenza or flu viruses for example mutate very quickly. So the same vaccine might not work year after year. In cases like that, animals may need to be vaccinated with a different vaccine that year to prevent the specific strain of influenza (just like with humans).
Just like antibiotics, vaccines have a withdrawal period. Humans don’t want those vaccines to be in the meat. So an animal cannot be harvested within a certain time period. The vaccines will have done their job and then been naturally flushed out of the body by the time the withdrawal period has passed. Each vaccine is a little different, but withdrawal periods can be around 21 days. Vaccination is a common and safe part of the pork industry. It helps ensure the health of the individual animal and the health of the whole herd. Just like humans should be vaccinated, animals should be too!