What defines a contraindication to vaccination?

• A. A condition that greatly increases the chance of a serious adverse reaction if the vaccine is given
• B. A mild fever after vaccination
• C. A history of common cold
• D. A past refusal

Answer: (A)

A contraindication to vaccination is a condition that greatly increases the risk of a serious adverse reaction if the vaccine is given. This is why that option is the best answer: it directly defines a medical reason to avoid vaccination. Mild fever after vaccination is a common, expected reaction and does not by itself mean you shouldn’t vaccinate. A history of a common cold also does not preclude receiving a vaccine, since short illnesses without severe symptoms don’t typically raise safety concerns for vaccines. A past refusal isn’t a medical contraindication; it’s a behavioral or personal choice, not a health condition that makes vaccination unsafe.