Key points are not available for this paper at this time.
Tom D. Y. Chin, John F. Foley, Irene L. Doto, Clifton R. Gravelle, Jean Weston, Morbidity and Mortality Characteristics of Asian Strain Influenza, Public Health Reports (1896-1970), Vol. 75, No. 2 (Feb., 1960), pp. 149-158
Chin et al. (Fri,) studied this question.