Growth characteristics of influenza virus type C in avian hosts. Brief report.

Influenza virus type C could be propagated to high yield in primary chick embryo kidney cell culture (PCEK) provided that trypsin (2 microgram/ml) was used as a medium supplement. The virus could also be titrated by plaque assay using PCEK host cells and influenza C virus that had been plaque-purified in PCEK cells could then be serially passaged to high titer using the allantoic route of 10--11-day-old embryonated eggs.