MMR vaccination for a 15-month-old infant is an example of which level of disease prevention?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Answer: (A)

This question is about levels of disease prevention, and the best fit is primary prevention. Giving the MMR vaccine to a healthy 15-month-old builds immunity before exposure, so measles, mumps, and rubella infections are prevented from occurring in the first place. That is the essence of primary prevention: stop the disease before it starts by preventing infection or enhancing host defense. Secondary prevention would involve finding disease early to prevent progression (like screenings), which this example does not do. Tertiary prevention aims to reduce complications after disease has already developed (such as rehabilitating after illness). Quaternary prevention relates to avoiding overmedicalization. So the MMR vaccination exemplifies primary prevention.