An otherwise healthy student in your class was infected with EBV (the virus that causes infectious mononucleosis - commonly referred to as "glandular fever") when she was a child, at which time she had merely experienced a mild sore throat and swollen lymph nodes in her neck. When she is exposed to EBV again later in life, she does not get sick or have any symptoms of mononucleosis.
Which of the following statements explains why your class mate does not exhibit symptoms of EBV infection?
A) She was likely infected with a weaker strain of EBV during her second exposure.
B) Complement proteins effectively controlled the EBV during the second infection.
C) Memory T cells quickly recognised the virus upon the second exposure and destroyed the virally infected cells.
D) Her innate immune response was better at recognising the EBV antigen during the second infection.

Question

Quizplus · Accepted Answer

The fact that the student was infected with EBV as a child and did not exhibit symptoms upon a later exposure suggests that her immune system was able to successfully mount a memory response. Memory T cells can recognise and destroy virally infected cells upon secondary exposure, thus preventing symptomatic infection.

An Otherwise Healthy Student in Your Class Was Infected with EBV