Polio vaccine incidents reduced public confidence in polio vaccine leading to a drop in vaccination rates. At the same time that Salk was testing his vaccine, both Albert Sabin and Hilary Koprowski continued working on developing a vaccine using live virus. During a meeting in Stockholm to discuss polio vaccines in November 1955, Sabin presented results obtained on a group of 80 volunteers, while Koprowski read a paper detailing the findings of a trial enrolling 150 people. Sabin and Koprowski both eventually succeeded in developing vaccines. Because of the commitment to the Salk vaccine in America, Sabin and Koprowski both did their
David Bruce (microbiologist) discouraged the experiments being carried by Zammit, and doubted his ability as a microbiologist. Eventually, when he learned of the positive results linking the fever with unpasteurized goat milk, Bruce tried to discredit the role of Zammit and take credit to himself. To a certain extent he succeeded, as it was renamed after him as brucellosis, however information about the role of Zammit has eventually surfaced. When he was transferred to South Africa, Bruce was sent to Zululand in 1894 to investigate the outbreak of cattle disease which the native called "nagana". In 1903, he identified the causative protozoan, and