Cell culture as a substrate for the production of influenza vaccines: memorandum from a WHO meeting.

Influenza has been a significant public health problem worldwide, with three pandemics during the past century. Immunization is the most effective measure to control an influenza pandemic. Since rapid production of large amounts of influenza vaccine depends on the availability of fertile hens' eggs to grow the viruses, there is an urgent need for the development of alternative cell culture systems, which would allow rapid scale-up of production in the event of a pandemic. This WHO meeting discussed the results of studies from several laboratories on the cultivation of influenza viruses in stable cell lines, and made recommendations for further work.