Important finding. It suggests that herd immunity could be achieved at a lower threshold than what's typically assumed, because the most susceptible people are the ones who get infected first. Some of those who remain uninfected do so because they may be less susceptible. 1/2 https://twitter.com/medrxivpreprint/status/1256522569987043328

What does it mean in a practical sense? Let's take New York. Seroprevalence studies done earlier show up to 20% were exposed to covid. It's higher now as epidemic grew. So if 30% of NYC population seroconvert, City could be closer to herd immunity than the 60% + presumed needed.