Vaccinations are a crucial aspect of infectious disease prevention. Prior to the invention of vaccinations, many individuals routinely died as a result of infectious diseases. The first vaccination was developed against smallpox, a disease that routinely plagued the world. It also killed approximately one third of the individuals who developed it. In time, other vaccinations were developed as well. They significantly reduced the incidence of childhood mortality. Vaccinations work by stimulating an immune response within the body. This immune response creates the antibodies necessary for future protection from the disease. In this method, individuals become immune or protected against the disease.

In order to understand how vaccinations work, one must have a basic understanding of the immune system. The immune system is how the body protects itself from foreign invaders. It is a complex system that utilizes multiple methods to do so. An important aspect of it involves antibodies and the development of antibodies specific for specific invaders. Anything foreign that enters the body and creates an immune response is referred to as an antigen. While white blood cells called macrophages digest invaders, portions of the invaders are still left behind. B cells, another immune cell, attack these antigens. B cells produce antibodies, which are utilized to do this action (Understanding how vaccines work, 2013, p. 1).

However, the antibodies that respond immediately to the threat are not specific antibodies. As such, they tend to take several days to effectively eliminate the threat. During this period, the individual may show signs and symptoms of illness. Within several days, the body creates antibodies that are specific for this threat. “The body keeps a few T-lymphocytes, called memory cells that go into action quickly if the body encounters the same germ again. When the familiar antigens are detected, B-lymphocytes produce antibodies to attack them” (Understanding how vaccines work, 2013, p. 1).

Vaccines work by stimulating this aspect of the immune system. An individual is injected with a form of the antigen. The antigen may be a bacterium or a virus. It is not the same microbe as the one that causes the disease. This would not be safe; it would likely result in the disease developing in the individual. Instead, scientists developed a safe form of the antigen that could be injected. There are several types of vaccinations. Attenuated live vaccinations utilize a live virus that has been significantly weakened. It is still strong enough to create the immune response in the individual; however, it is not strong enough for the individual to develop the actual disease. An inactivated virus vaccine uses a dead form of the virus. Toxoid vaccines are utilized for bacterial diseases. The bacterial toxins are weakened before being injected in the individual. Vaccines are often given in several doses. As a weakened form of the antigen, one vaccination alone will not create sufficient immunity in an individual (Understanding how vaccines work, 2013, p. 1).

Once a person receives an adequate dose of a vaccination, his or her immune system will have mounted a sufficient response. If the individual is exposed to the antigen again, the immune system will trigger a response based upon its memory of the antigen. This will result in antibodies being released. The individual will not develop the disease or will develop a much weaker version of the disease (Understanding how vaccines work, 2013, p. 2).

It is possible for an individual to be exposed to the disease and receive the vaccination during the incubation period. This often occurs with the flu. The person then receives the vaccination and develops the disease. This is the reason many individuals believe the flu vaccination “gave” them the flu. They merely were exposed before they had developed an immunity to the disease. It is important to explain this to individuals. Otherwise many individuals avoid the flu vaccine every year due to incorrect information.