It is important to understand the different meanings of an adverse event following immunization (or AEFI) and an adverse vaccine reaction. Can you tell the difference? Select the right answers:

A. An adverse vaccine reaction is a vaccine-related event caused or precipitated by a vaccine when given correctly.
B. An adverse vaccine reaction can be caused by errors in the administration of the vaccine.
C. An adverse vaccine reaction can be the result of unrelated coincidence.
D. An adverse event following immunization can be due to all of the causes stated in A, B, and C.


Answers A and D are correct.