" Capps did write the JAMA article. He reported finding the masks so successful that after less than three weeks of experimenting he had abandoned testing and simply started using them as “a routine measure.” He also made the more general point that “one of the most vital measures in checking contagion” is eliminating crowding. “Increasing the space between beds in barracks, placing the head of one soldier opposite the feet of his neighbor, stretching tent flags between beds, and suspending a curtain down the center of the mess table, are all of proved value.” To prevent a few arriving individuals from infecting an entire camp, he also repeated Welch’s recommendation to isolate transferred troops. "
― John M. Barry , The Great Influenza: The Story of the Deadliest Pandemic in History