Timing of different virus neutralizing 19S and 7S antibodies in natural coxsackie infections of newborn babies and adults.

Neutralizing Coxsackie antibodies arising from natural infections with Coxsackie virus type B3 or B5 were studied in adults and newborn babies. No differences could be found between the antibody response of the newborn babies and that of the adults. The antibody titres rose approximately as rapidly in the babies as in the adult patients, and the means of the peak titres did not differ significantly in the two groups. Early in the infection the neutralizing antibodies of both newborn babies and adults were exclusively IgM. There was a gradual shift to IgG in the course of 3 months, and this shift was as rapid in babies as in adults.