Quantitative Aspects of Influenza Virus Multiplication

Abstract

It is not the subject matter of these studies which unites them in a series but the intent of showing that the present knowledge of influenza virus multiplication lends itself to quantitative and theoretical treatment. The three preceding papers were concerned with different facets of the problem; here an attempt will be made to define and estimate the constants common to them all.Relation between infectivity and haemagglutinating power. The infectivity of influenza virus preparations is usually expressed as the number of 50%-infective doses (ID50) contained in a standard volume. To find out how many infective units constitute a haemagglutinating dose, we collected the data from the protocols kept by five members of the Hall Institute. Only results fulfilling the following requirements were considered: (a) the test material was grown from dilute seed (b) for less than 48 hours, and (c) both infectivity and haemagglutinin titrations were done on the day of harvest.