Immunization against cyanolophia

Abstract

When in June, 1915, I was introduced to the study of Cyanolophia by A. von Wassermann, Berlin, I performed, under his guidance, several series of experiments to immunize against this chicken disease caused by a filtrable virus. We tried to establish active immunity by treating the animals with attenuated inoculated brain, attenuated inoculated liver, attenuated serum inoculated into bone marrow and virulent sera of different ages and different strengths. The attenuation was effected either by “cultivating” the virulent tissues in chicken plasma after the tissue culture method or by weakening the virulent serum by “cultivation” in bone marrow and chicken plasma. Our tentative experiments, from June, 1915, to October, 1915, did not give results. Only one chicken resisted an inoculation of virulent brain after the following treatment. This chicken, No. 13, had received two inoculations with serum which was obtained 17 hours after the inoculation of virulent brain into another animal. We applied one inoculation with attenuated brain tissue and later bone marrow with attenuated serum was implanted under the skin. After a short interval this animal received another serum treatment and then two days later a lethal dose of virulent brain. It survived this strongest test, while a control chicken which was inoculated with the same brain, but had not undergone these different treatments, died in due time. The immunity of No. 13 was gained without intention. Owing to the scarcity of chickens to be used for experimental purposes at this time in Germany, we had always used the same chickens for our experiments, after the preceding inoculations with the different attenuated materials proved ineffective. So we did not expect No. 13 to live after we inoculated it with virulent brain.