Which of the Following Statements Is TRUE

Multiple Choice

Which of the following statements is TRUE?

A) Live vaccines contain microorganisms that multiply in the host.
B) Inactivated toxins are used in some vaccines.
C) Vaccines made from killed or inactivated organisms usually require more than one dose.
D) The MMR (measles-mumps-rubella) vaccine rarely causes serious side effects.
E) All of the above.