Differences in the Epstein-Barr virus gp350 IgA antibody response are associated with increased risk for co-infection with a second strain of EBV.

Background: The EBV viral glycoprotein gp350 has been proposed as a candidate antigen for an EBV vaccine. However, the proposed formulations of these vaccines have not taken into account the presence of two unique EBV strains (EBV-1 and EBV-2) present in areas of high incidence of the EBV associated cancer, Burkitt's lymphoma.

Methods: In this study, we analyze the kinetics of EBV-1 and EBV-2 infection in an asymptomatic infant cohort from Kisumu, Kenya. We also analyzed the kinetics of the antibody response against five EBV antigens, gp350 (IgG and IgA), VCA (IgG), EBNA-1 (IgG), EAd (IgG), and Zta (IgG).

Results: We observed a high frequency of co-infection with both EBV types over time, with the only observable defect in the antibody response in infants co-infected being a significantly lower level of anti-gp350 IgA at peak response. Gp350 IgA levels were also significantly lower in co-infected infants 2.5 months post-infection and at the time of co-infection.

Conclusions: These results suggest that anti-gp350 IgA antibodies may be important for sterilizing immunity against secondary infection. These findings have implications for the development of an efficacious EBV vaccine to prevent both EBV-1 and EBV-2 infection in a population at high risk for Burkitt's lymphoma.