https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2126288/pdf/449.pdfFrom January 21 – June 4, 1918, an experimental bacterial meningitis vaccine cultured in horses by the Rockefeller Institute for Medical Research in New York was injected into soldiers at Fort Riley.
https://translational-medicine.biomedcentral.com/articles/10.1186/1479-5876-2-3The same week that Homer Moody and a dozen others in Jean, Kansas, fell ill, a young soldier named Dean Nilson came home to Jean on leave from Camp Funston, located three hundred miles away within the vast Fort Riley military reservation.