
Disclosed herein is an infection protectant which is excellent in infection protective effects and is also safe. .kappa.-Casein, a sialic-acid-conjugated protein derived from cow milk, and a glycomacropeptide derived from .kappa.-casein, each of which is useful as an active ingredient in this invention, have been found to be effective for the prevention of adhesion of E. coli on cells and also for the inhibition of transformation of lymphocytes by EBV and also to have strong HI activity against ...











