How do vaccinations function in preventing infectious disease?

Vaccinations work by stimulating the immune system to produce a response against specific infectious agents.

Vaccinations are a form of active immunity, where the body is exposed to a weakened or dead form of a pathogen or a part of it, such as a protein or sugar molecule. This exposure triggers the immune system to produce antibodies and immune cells that can recognise and destroy the pathogen if it enters the body again. The immune system also develops memory cells that can quickly respond to future infections by the same pathogen.

Vaccinations have been successful in preventing many infectious diseases, such as polio, measles, and tetanus. They have also reduced the incidence of other diseases, such as hepatitis B and human papillomavirus (HPV) that can cause cancer.

Vaccinations are usually given in childhood, but some require booster shots in adulthood to maintain immunity. The timing and frequency of vaccinations depend on the disease and the individual's age, health status, and exposure risk.

Vaccinations are a safe and effective way to prevent infectious diseases, but they are not 100% effective. Some people may not respond to the vaccine, and some pathogens can mutate or evolve to evade the immune response. Therefore, it is important to continue to practice good hygiene and follow public health guidelines to reduce the spread of infectious diseases.