A dental assistant who had the flu does not get sick when exposed again. What type of immunity is this?

Correct answer: D. Active natural immunity

• A. Passive immunity involves receiving pre-formed antibodies (e.g., from another source), not the body's own immune response to infection.
• B. Artificial immunity refers to immunity gained through vaccination, not natural infection.
• C. 'Permanent' is not a standard immunologic classification term used to describe this mechanism.
• D. Correct. Active natural immunity occurs when the body's own immune system produces antibodies in response to actual infection (natural exposure), providing lasting protection against future exposure to the same pathogen.