Which of the following statements is TRUE?

Question

Quizplus · Accepted Answer

A) True, live vaccines contain weakened or attenuated microorganisms that can reproduce in the host and stimulate an immune response. 
B) True, some vaccines contain inactivated toxins or toxoids that have been treated to remove their toxic properties, but still mimic the antigens of the pathogen. 
C) True, vaccines made from killed or inactivated organisms often require several doses to provide enough antigen exposure for the immune system to develop a protective response. 
D) False, like all vaccines, the MMR vaccine can cause side effects, although serious reactions are rare.

Which of the Following Statements Is TRUE