ANTIGENICITY OF THE M PROTEINS OF GROUP A HEMOLYTIC STREPTOCOCCI

Abstract
Highly purified M proteins were used for determining cutaneous hypersensitivity and type-specific circulating antibodies in normal adults and infants. 80% of 91 adults and 8% of 59 infants exhibited a transient delayed cutaneous reaction to at least two of types 12, 14, and 24 M proteins. Antibodies assayed by passive hemagglutination were observed in 90% of the adults and 13% of the infants.