In 1944, Stanley described in detail the preparation and properties of influenza virus vaccine produced in embryonated hen eggs, concentrated and purified by differential centrifugation and ...

Influenza virions can take a variety of shapes, from the classic spherical or kidney bean morphology found in most lab-adapted strains to much longer filamentous forms that can reach over 20 nm in ...

and B/Shandong/7/97 were incubated within the allantoic cavity of embryonated eggs, 10 days old, in an environment maintained at 37 °C and 50% humidity. Each egg was inoculated with 100–1000 plaque ...