Factors involved in determining whether infectious mononucleosis occurs after primary EBV infection may include age, dose of virus received, and various genetic markers. A study by McAulay and colleagues reported in this issue of the JCI shows that the presence of certain HLA class I alleles correlates with the incidence and severity of infectious mononucleosis (see the related article beginning on page 3042). These same HLA alleles are also risk factors for EBV-associated Hodgkin lymphoma (HL), supporting recent epidemiology that indicates that a history of infectious mononucleosis predisposes to HL. Recent studies suggest that an EBV vaccine might help to prevent infectious mononucleosis, and further development of this should now be considered.
