Which EBV serologic marker appears at the onset of symptoms and remains detectable for life?

Which EBV serologic marker appears at the onset of symptoms and remains detectable for life?

• A. anti-VCA IgM
• B. anti-VCA IgG
• C. anti-EBNA
• D. anti-EA

Answer: (B)

When evaluating EBV serology, the timing of antibody development guides what each marker signifies. Anti-VCA IgG is produced early in infection and, unlike many other markers, persists for life. This makes it the best indicator of a past EBV infection that began with symptoms and has left an enduring antibody record. In contrast, anti-VCA IgM appears with onset but fades over weeks, anti-EBNA antibodies appear later after the acute phase and also persist for life but don’t rise at symptom onset, and anti-EA can appear during active replication and is not a stable lifelong marker. Therefore, anti-VCA IgG is the marker that appears at onset and remains detectable for life.

When evaluating EBV serology, the timing of antibody development guides what each marker signifies. Anti-VCA IgG is produced early in infection and, unlike many other markers, persists for life. This makes it the best indicator of a past EBV infection that began with symptoms and has left an enduring antibody record. In contrast, anti-VCA IgM appears with onset but fades over weeks, anti-EBNA antibodies appear later after the acute phase and also persist for life but don’t rise at symptom onset, and anti-EA can appear during active replication and is not a stable lifelong marker. Therefore, anti-VCA IgG is the marker that appears at onset and remains detectable for life.