Evaluation of anti-norovirus IgY from egg yolk of chickens immunized with norovirus P particles.

Noroviruses (NoVs) are a leading cause of epidemic acute gastroenteritis affecting millions of people worldwide. Understanding of NoV remains limited due to the lack of a cell culture system and small animal models. Currently, there are no effective vaccines or antivirals against NoVs. In this study, an approach for large-scale production of anti-NoV antibodies for use as a potential treatment for NoV disease using passive immunization was evaluated. NoV-specific immunoglobulins (IgYs) were produced by immunizing chickens with NoV P particles. The birds continuously produced high titers of antibodies in their eggs for at least 3months, in which NoV-specific antibody levels reached 4.7-9.2mg/egg yolk. The egg yolk antibodies strongly reacted with NoV P particles by both ELISA and Western blot and blocked NoV virus-like particle (VLP) and P particle binding to the histo-blood group antigen (HBGA) receptors with a BT(50) of about 1:800. The blocking activity of the chicken IgY remained after an incubation at 70°C for 30min or treatments at pH 4-9 for 3h. These data suggested that chicken IgY could be a practical strategy for large-scale production of anti-NoV antibodies for potential use as passive immunization against NoV infection, as well as for diagnostic purposes.