ORAL PASSIVE-IMMUNIZATION EFFECT OF ANTI-HUMAN ROTAVIRUS IGY AND ITS BEHAVIOR AGAINST PROTEOLYTIC-ENZYMES

The neutralization titer of anti-human rotavirus (HRV) IgY was complet ely inactivated by pepsin at pH 2.0. However, it was not significantly affected by trypsin or chymotrypsin under certain conditions. The imm unological activity of the IgY was observed in the intestine of suckli ng mice for 2h after oral administration and the activity rapidly decr eased thereafter. The effects of oral supply of IgY were thus estimate d for HRV-induced diarrhea in suckling mice and it was found that a pr evious supply of the IgY (1 h before HRV infection) completely prevent ed the HRV-induced diarrhea. The preventive effect was decreased as th e time gap between IgY administration and HRV infection was longer. Ho wever, the oral supply of the IgY within 24h after HRV infection was s till effective and decreased the incidence of HRV diarrhea in suckling mice.