Long term persistence of IgE anti-hepatitis A virus antibodies in adult serum post vaccination. (113.9)

Abstract

Abstract Rationale: The role of IgE in immunity against Hepatitis A has not been studied. Methods. Serum was obtained from an adult who was vaccinated with Hepatitis A virus (HAV) (Havrix®) in 2005 and again in 2009 and compared with pre vaccination status and natural HAV infection. Serum was assessed for the presence of IgE anti-HAV antibody (modified Immunoblot/ELISA, spectrophotometry) over seven years post vaccination and compared with IgG and IgM virus specific antibodies.. Results. Serum obtained from HAV adult contained IgE anti-virus antibodies which increased over 1.5 years post initial vaccination. In contrast, serum levels of IgE anti-HAV antibodies increased 6 fold two years after 2nd vaccine booster compared with pre-booster levels (1.2OD450 vs 0.21OD450, p<0.05). The rise of IgE anti-HAV levels increased proportionally with time after booster. Interestingly, serum IgE HAV antibody levels seven years post vaccination were comparable to levels of IgE anti-hepatitis antibodies in natural HAV infection (1.2OD450 vs 1.23OD450). Similar patterns were not observed with IgG and IgM anti virus antibodies with respect to consistency and rate of rise. Conclusions. This is the first description of the presence of IgE anti-HAV antibodies, and the first demonstration of its long term persistence serum seven years post vaccination. Understanding the role of IgE anti-virus antibodies may provide insight into vaccine physiology with respect to protection against viral infection.