Which of the following is an example of primary prevention?

• A. Screening
• B. Rehabilitation
• C. Vaccination
• D. Antibiotic treatment for infection

Answer: (C)

Primary prevention aims to prevent disease from occurring. Vaccination does this by training the immune system to recognize a pathogen so that infection is prevented or its severity is reduced if exposure happens. Because the goal is to stop illness before it starts, vaccination is a quintessential example of primary prevention.

Screening, on the other hand, looks for disease before symptoms develop to catch it early and prevent progression, which is secondary prevention. Rehabilitation occurs after illness has begun to restore function and reduce complications, which is tertiary prevention. Treating an active infection with antibiotics addresses an existing illness rather than preventing it, so it is not primary prevention.