How do Vaccines Work?
Learn more about how vaccines work and how they contribute to a healthier world.
Frequently Asked Questions
- What are vaccines?
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.
- What are vaccines made of?
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.
- What is vaccination?
Vaccination and immunisation are used interchangeably but they have different meanings. Vaccination is simply the administration of a vaccine.
- What is immunisation?
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'.
- What is herd immunity?
Videos on Vaccines
If you're interested in learning more about vaccines and how they work, see the following videos:
Bill Gates: Vaccines Save Lives
Bill Gates discusses his views on vaccines and their lifesaving ability, using smallpox and polio as examples
Search the Gates Foundation website for further information.
How Vaccines Work: The Complete History of Vaccines
See an overview of the history of vaccines, and find out how vaccines stimulate an immune response.
Credit: Carrington College
Immunity and Vaccines Explained
Learn more about how vaccines work to stimulate our immune system to keep us from getting sick.
The Chain of Protection
Professor Robert Booy explains the importance of immunisation and vaccination, and hear real life stories of the impact infectious diseases has had on families.
Search The Chain of Protection website for more videos and information on vaccines and vaccination.
Vaccines and Herd Immunity
Paul Andersen explains how immune individuals in a population give the entire group herd immunity. Concepts of immunity, vaccines, basic reproduction number, and herd immunity threshold are discussed.
Search the Bozeman Science website for more information on vaccines and vaccination.