Which term describes the prevention of disease by vaccines?

• A. Immunoprophylaxis
• B. Chemoprophylaxis
• C. Forceful Exertions
• D. Observations

Answer: (A)

Immunoprophylaxis is the idea of preventing disease by teaching the immune system through vaccination. Vaccines present a safe piece or inactivated form of a pathogen, prompting the immune system to produce antibodies and memory cells. When the real pathogen shows up, the immune system recognizes it fast and mounts a rapid, targeted response, often stopping the illness before it develops or making it much milder.

Chemoprophylaxis, by contrast, prevents infection with drugs such as antibiotics or antimalarials—a different strategy that doesn’t involve training the immune system. The other options don’t relate to preventing disease through vaccines.