How do Vaccines Work?

In order to understand how vaccines work, it is important to first understand what vaccines are. So what are vaccines? Vaccines protect us from catching a disease by tricking the body into thinking that the vaccine particles are the real bug (virus/bacterium). The vaccine does not cause the disease but the body reacts to it as if the disease was real.

Vaccines are usually made from live attenuated (weakened) or inactivated (killed) forms of the microbe, its toxins or surface particles. These forms don't cause the disease but work to stimulate the production of antibodies in the body. It takes the body around two weeks to develop the antibody response which gives the immunity.

Vaccination and immunisation are used interchangeably but they have different meanings. Vaccination is simply the administration of a vaccine.

So now you know what vaccines are. How do they work? After the vaccination, the human body has a clever system to keep a record of the "offender" in special cells called memory cells. These memory cells behave like secret agents by making sure that the same invader will be neutralised with antibodies if it is encountered again. When this process is complete, the vaccinated person is immunised. An immunised person will be able to avoid catching the disease and therefore will stop the spread to other people.

The next important step to get rid of the disease in the community is to ensure that at least 95% of people are vaccinated - this is called 'herd immunity'.

Herd immunity is an important step to get rid of a disease in the community. It involves ensuring that at least 95% of people are vaccinated. Find out more about herd immunity or watch the video by Bozeman Science for an easy explanation.