> Early implementation of certain interventions, including closure of schools, churches, and theaters, was associated with lower peak death rates, but no single intervention showed an association with improved aggregate outcomes for the 1918 phase of the pandemic.
In other words, a similar amount of people died regardless of these interventions, but the cases were spread out over a longer time period. They also note that the virus spreads as soon as interventions are relaxed, suggesting many cities just delayed the infection.
Edit: thanks for the comments below - my comment was just to point out that these interventions didn't cut the death rate in half, as a quick reading of the submitted headline might suggest.