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METHODS FOR SCREENING IN VITRO AND IN VIVO FOR AGENTS ACTIVE AGAINST MYXOVIRUSES

Since influenza viruses are an important target for chemotherapy, it is noteworthy that when this Academy last considered Antiviral Substancesl, no convenient tissue culture methods were described for testing substances for activity against these viruses. The probable reason is that most antiviral screening methods require that the virus concerned should form plaques under an overlay, or produce massive destruction of cells bathed with a fluid medium, and influenza viruses generally do not produce such effects. Reports appear from time to time claiming that at last a satisfactory plaque method for influenza viruses has been developed, and indeed nine methods were listed in a recent paper2, but so far none has found general acceptance. Another technical point is that in many convenient tissue culture systems, influenza viruses either fail to grow or else produce non-infectious virus.