What is a vaccine? And how does it work?

Vaccines teach our bodies’ defenses – the immune system, how to protect the body against an invading microorganism and the particular disease it causes.

  • Some vaccines contain the same microorganism that cause disease (for example, measles vaccine contains measles virus, and Hib vaccine contains Hib bacteria.), and that same microorganism has been either killed or weakened to the point that they don’t make you sick.
  • Some vaccines contain only a part of the microorganism that causes the disease such as proteins from the pathogen’s surface.
  • Newer, still developmental vaccines, even contain only the genetic material of the microorganisms.

Vaccination is considered one of the greatest healthcare interventions of our time, having saved millions of lives each year for roughly a century and greatly reduced disease, disability and inequity worldwide. Only clean water, which is also considered to be a basic human right, has performed better