CD79A and Epstein-Barr virus infection: The observation of undetectable serum VCA-IgA levels in North African patients under thirty could have several potential explanations: (1) recent EBV infection in this region, where immune systems may not have had sufficient time to produce detectable levels of VCA-IgA antibodies; (2) variability in EBV strains circulating in North Africa among younger individuals that may not strongly induce VCA-IgA antibody production; or (3) individual genetic factors that influence an individual’s immune response to infections, including EBV.