Effect of several unpurified milk preparations on experimental influenza infection in mice.

Investigations were performed as regards the effect of the in vitro contact of influenza virus A/PR/8/34 (H1N1) with different milk preparations: boiled milk, milk acidified with lactic acid, supernatant from boiled yoghourt. It was the latter preparation that had the highest efficacy as regards the reduction of hemagglutinating (HA) titer following direct in vitro contact and the course of experimental influenza infection in mice. In the case of animals inoculated with influenza virus exposed to yoghourt supernatant HA titers in the lung homogenates were lower, mortality rates were reduced and the mean survival time was longer than in controls infected with untreated virus. Considerations are made on the possible mechanisms of the antiinfluenza action of yoghourt supernatant.