How do vaccines work?

Vaccines work by stimulating the immune system to recognise and fight specific pathogens, such as viruses or bacteria. They contain weakened, inactivated, or harmless parts of the pathogen, like proteins or genetic material, which cannot cause the disease. When the immune system encounters the vaccine, it produces antibodies and memory cells to defend against future infections. This provides immunity, protecting individuals and reducing the spread of diseases in the community. Vaccination has been instrumental in eradicating diseases like smallpox and controlling others, such as polio and measles.