Alternate Passage of Influenza Virus. A Comparison of the Effects of Serial Passage and Alternate Passage of Type B Influenza Virus in Hamsters

Abstract

The effects of alternate passage in eggs and hamsters on the adaptation of a strain of type B influenza virus to hamsters have been described. The pathogenicity for hamsters of virus passaged in this manner was maintained and appeared to be somewhat enhanced, but the line of virus did not become adapted to hamsters. On the contrary, the process of adaptation appeared to be retarded following a number of alternate passages in eggs and hamsters. The implication of these findings with respect to the phenomenon of adaptation has been discussed.