Vaccination against measles gives
- A. natural passive immunity
- B. artificial passive immunity
- C. natural active immunity
- D. artificial active immunity
Explanation
It is artificial because the antigen is given deliberately rather than met by chance, and active because the person's own lymphocytes respond and form memory cells, so protection is slow to appear but lasts for years. Passive immunity means receiving ready made antibodies, which acts at once but fades within weeks and leaves no memory. Recovering from an actual attack of measles gives natural active immunity.