Common antigen between coxsackievirus A 16 and enterovirus 71.

Cross immunofluorescence revealed that coxsackievirus A 16 (CA 16) shared a common antigen with enterovirus 71 (E 71). The cross reactivity of these two serotypes was also examined by complement fixation test with purified virus preparations fractionated by sucrose density gradient centrifugation and two peaks of antigenicity were detected, one being type-specific and the other cross-reacting. The common antigen was heat-stable and attributable to empty capsids. Immuno-diffusion also revealed the common antigen. Infants without antibody to E 71 developed complement fixing and precipitin antibody to E 71 after recovery from hand, foot and mouth disease caused by CA 16.