THE VARIATION OF ANTIGENIC PATTERN AND OF MOUSE VIRULENCE IN AN INFLUENZA VIRUS CULTURE

Abstract

A marked antigenic difference exists between a line of the Cam strain of influenza A prime virus that had been through 30 or more mouse passages and the original line of that same strain that had been maintained in chick embryos. Although antigenic change may occur with mouse adaptation, an influenza virus that is relatively avirulent for mice may be converted into one that is highly virulent for that species without any apparent change'' in its antigenic pattern.