Why do immunizations require two doses?
A) The first dose stimulates the effector cells only, and the second dose stimulates the memory cells only.
B) The first dose stimulates the primary immune response, and the second dose stimulates the secondary immune response.
C) In case the first dose isn't enough to induce immunity, a second dose is given.
D) It is a way for doctors to make more money.
E) Both c and d are correct.

Question

Quizplus · Accepted Answer

The first dose of an immunization stimulates the primary immune response, which involves the activation of effector cells. The second dose is given to stimulate the secondary immune response by activating memory cells, which will provide long-term immunity. This is why two doses are often required for long-term protection against a particular disease.

Why Do Immunizations Require Two Doses