On the topic of chain link fence, here's what a PBS documentary said about mask use during the 1918 Spanish Flu pandemic.
"All of America, it seemed, put on masks. At last, many thought, they were safe. But masks didn't help. They were thin and porous -- no serious restraint to tiny microbes. It was like trying to keep out dust with chicken wire."
"A resolution shot through Congress, giving the Public Health Service a million dollars to fight the flu. Biochemists around the country worked feverishly to develop a vaccine. [...] But even vaccines didn't help."
On the topic of chain link fence, here's what a PBS documentary said about mask use during the 1918 Spanish Flu pandemic.
"All of America, it seemed, put on masks. At last, many thought, they were safe. But masks didn't help. They were thin and porous -- no serious restraint to tiny microbes. It was like trying to keep out dust with chicken wire."
"A resolution shot through Congress, giving the Public Health Service a million dollars to fight the flu. Biochemists around the country worked feverishly to develop a vaccine. [...] But even vaccines didn't help."
https://www.pbs.org/wgbh/americanexperience/films/influenza/
http://archive.today/IYjlo