Following infection with the virus of influenza, both ferrets and mice develop a state of active immunity to reinfection. The serum of these animals contains neutralizing antibodies, as evidenced by the capacity of the serum to confer passive protection to mice against infection with the P.R.8 and Phila. strains of the virus of human influenza. Rabbits which are apparently insusceptible to infe...

An immunogenic fraction from Pasteurella multocida was found to consist chiefly of a high-molecular-weight protein-polysaccharide complex containing 25 to 27% protein and 10.7% carbohydrate. The starting material was obtained by differential centrifugation at 105,000 X g of saline extract of P. multocida cells and further purified by gel filtration on Sepharose 2B. Three peaks were usually obta...

The soluble specific substance of Pneumococcus Type I has been chemically isolated from the bacterial cells and from autolyzed cultures as an acetyl polysaccharide. So far as could be determined by the methods employed, the acetyl polysaccharide in highly purified form absorbs from Type I antipneumococcus serum all demonstrable type-specific precipitins, agglutinins and protective antibodies. M...

Note.?Single sores represent about 40 per cent of all cases. It is suggested that a single sore, naturally acquired, be allowed to run its course, if not on the face, and if protected from bites. The development of an active immunity from one infection with oriental sore is generally accepted. Inoculation with attenuated cultures of the parasite is being successfully carried out in some endemic...