The capacity of certain fatty acids at pH 7.5 to inactivate the virus of epidemic influenza has been demonstrated. Most effective of these are oleic, linolic, and linolenic acids.
Studies were made of such variables as pH, rate of inactivation, and ratios of reactant concentrations, using oleic acid as a prototype of the effective acids. Attempts to recover active virus from inactive mixtures by decrease in pH, dialysis, dilution, or addition of calcium chloride solution to inactivated virus have been unsuccessful.
The stability of virus at different hydrogen ion concentrations has been determined.
Quantitative comparisons have been made of the immunizing capacity of fully active virus and virus rendered non-infectious by treatment with oleic acid. It was found that while the infectious property of the virus is removed the immunogenic capacity is essentially unaltered.
The possible mechanism by which the soaps act upon influenza virus has been discussed.