Since early 2020, wastewater concentrations of COVID RNA have been available for the greater-Boston area (lower figure). These measurements could predict death counts in the surrounding State of Massachusetts, and linear models that accounted for fatality rates and time lags fit reasonably well (upper figure).
Noticeably, death counts per wastewater RNA dropped from the first half of 2020 (H1) to the second half (H2) by nearly 10x. Why this big change, which occurred before the arrival of vaccines? Later lethality reductions were far smaller.
Code for the calculation, including an updated graph, is available here.
Please keep any comments on topic.
We knew fairly early that IFR (Infection fatality rate) was skewed by age cohort. We also knew the importance of complicating factors, mostly obesity. Almost all deaths occurred among the old and the fat. We already knew before the first case that this was likely with a respiratory virus.
We have known for a hundred years that the best thing to do is to get patients outdoors, where even a slight breeze can dissipate a vapor cloud, and sunlight harms viruses. So, we did the opposite.