Determination of group a streptococcal anti-M type-specific antibody in sera of rheumatic fever patients after 45 years.

Group A streptococcal M type--specific protective antibodies-especially their persistence in humans--are incompletely understood. Such information is essential for understanding the epidemiology and pathogenesis of these infections and their sequelae and is equally crucial for producing a group A streptococcal vaccine. We studied 2 adults for type-specific antibody 45 years after they experienced documented rheumatic fever.