The definitive microbiological study of the 1918-1919 influenza pandemic, conducted through the full resources of the Mayo Foundation. No consideration of this pandemic could be complete without proper reference to this work. This book contains the full text, tables and figures from the original publications in JAMA, 1919, and the Journal of Infectious Diseases, 1920. Also included in the Foreword are discussions of (1) underlying theoretical considerations and methods of oral and accelerated vaccine production, (2) how and why the PHS and NIH have inappropriately misdirected attention from this vital body of work, and (2) evidence that pre-existing oral infections were a factor contributing to the severity of symptoms of pneumonia victims, including death.