Inactivation of influenza and other viruses by a mixture of virucidal compounds.

A mixture of benzalkonium chloride, Triton X100, and citric acid (Resiguard F) had a marked virucidal effect on lipid-containing deoxyribonucleic and ribonucleic acid viruses, such as vaccinia virus, herpesvirus, and influenza virus. Adenoviruses and picornaviruses were more resistant to inactivation. Electron microscopy showed that influenza particles became aggregated in the presence of Resiguard F and that the outer fringe of hemagglutinin and neuraminidase spikes seen in control virus preparations became indistinct. The mixture had no detectable antiviral activity in mice infected with influenza AO/PR/8/34 virus, and this was attributed to the reduced virucidal effect of Resiguard F in the presence of serum proteins.