Passive protection effect of chicken egg yolk immunoglobulins on enterovirus 71 infected mice

The objective of this study is to evaluate the passive protective efficiency of immunoglobulin in yolk (IgY) specific against human enterovirus type 71 (EV71). The antibody was raised by intramuscular immunization to 10 White Leghorn hens, with inactivated human EV71 serving as the antigen. The titer and specificity of the antibody were analyzed from purified IgY in the egg yolks of immunized hens. Results indicate that the titer of IgY specific against EV71 increased from the third week after the first immunization. The content of total IgY was 190 ± 26 mg/yolk, with an average concentration of specific IgY of 6.34 ± 3.38 mg/yolk in the eggs from 3 to 18 wk after immunization. The results of the neutralization effect of specific IgY in EV71-challenged mice demonstrate that the EV71-specific IgY, either by intraperitoneal injection or oral administration, was able to significantly reduce the morbidity and mortality in EV71 infected mice pups.