"Nearly." So lets say they're 99% effective. 100 people = 1 person. 1000 people = 10 people. 8.2 million people (the population of NYC) = 82,000 people. That'

"Nearly." So lets say they're 99% effective. 100 people = 1 person. 1000 people = 10 people. 8.2 million people (the population of NYC) = 82,000 people. That's a non trivial number, and that's just for one city.