5947615 \'How to Avoid Influenza\' by Wilmer Krusen, Director, Department of Public Health and Charities by American School, (20th century); 28x36 cm; Free Library of Philadelphia; (add.info.: This October 1918 poster was created in response to the virulent ?淪panish Flu??(later called the swine flu, and today, the H1N1 virus), which affected Philadelphia for a year, beginning in September 1918. These posters were printed in many languages, to make sure all residents of Philadelphia were informed. Department of Public Health and Charities Oct, 22,1918.); by Free Library of Philadelphia ; American, out of copyright.