All major indicators of COVID-19 transmission in the United States continued to fall this week. Nationally, cases have been falling for six weeks, hospitalizations have been dropping sharply for five weeks, and deaths have been declining for four weeks. The average number of people in the hospital with COVID-19 this week was just under the average we saw during the high points of the April and July hospitalization surges. States and territories reported 14,463 COVID-19 deaths in the past seven days, the first weekly total under 15,000 we’ve seen so far in 2021.
The decline in cases and deaths appears to have slowed this week. After so many weeks of very rapid improvements in reported cases and deaths, a slowing of those declines was inevitable. But we don’t think that a true plateau is the only or even likeliest explanation for what we’re seeing this week. Instead, we think we’re once again seeing the equivalent of a holiday-reporting effect.
Two confounding events that occurred last week—Presidents’ Day and the beginning of a major winter storm that knocked out power for millions of Americans—resulted in slowdowns in case reporting. As we’ve seen with other holidays and storms, these kinds of disruptions produce a predictable series of reporting artifacts: first an artificial drop, then an artificial rise. We should always look for confounding factors before interpreting the data as suggesting a change in the direction of the pandemic—and in this week’s data, we found them. Artificially low numbers from last week’s disruptions make this week’s case and death declines look smaller by contrast, and make the daily numbers look as though they’re reversing direction, especially as backlogs roll in.
The death-reporting process was also affected by the federal holiday and the storm, producing similar artifacts in the data. Even hospitalization numbers appear to have wobbled in a similar way, probably as a result of both small reductions in reporting and small reductions in the number of people who sought care at hospitals over the three-day weekend and during major regional storms.