Biology – Infectious diseases | e-Consult

A vaccine works by exposing the body to a weakened or inactive form of a pathogen, or a part of it (like a protein). This triggers the immune system to recognise the pathogen as foreign and produce antibodies and memory cells specific to that pathogen. These memory cells allow the body to mount a rapid and effective immune response if the person is exposed to the live pathogen in the future, preventing or reducing the severity of the disease.

Example: The Measles, Mumps, and Rubella (MMR) vaccine protects against measles, mumps, and rubella. The vaccine contains weakened versions of these viruses. Upon vaccination, the immune system produces antibodies against these viruses, providing immunity. If the individual is later exposed to the live viruses, the memory cells will quickly produce antibodies to neutralize the infection.