The virus takes time (2-3 weeks) to kill people, and the prevalence was presumably measured within the last week.
Therefore, we have to take out the cases that occurred in the last week or two. I would suspect that 50% is on the upper end of how much the death lag could skew the results, but 20-50% doesn't seem unreasonable.
Therefore, we have to take out the cases that occurred in the last week or two. I would suspect that 50% is on the upper end of how much the death lag could skew the results, but 20-50% doesn't seem unreasonable.