COVID-19 Deaths, Excess All-Cause Mortality in US and Other Nations

Over the nearly three-year span of the COVID-19 pandemic, the US and other countries have experienced a shifting in dominant viral variants, from Delta in the second half of 2021 to Omicron, which first gained traction in early 2022. Much of the world received access to COVID-19 vaccines beginning in early 2021, which greatly reduced the potential deaths from these variants. Nonetheless, the US experienced higher death rates than other countries during Delta and the winter Omicron wave.

A newly released research letter in JAMA delved into how many potential deaths could have been averted in the US had it experienced the same COVID-19 mortality rates and excess all-cause mortality rates as its peer nations. Scientists at Brown University’s School of Public Health and University of Pennsylvania’s Perelman School of Medicine compared vaccination rates, COVID-19 mortality rates, and excess all-cause mortality rates in the US to those of 20 nations with a population of 5 million or more and gross domestic product higher than $25,000 per capita. The US data was further segmented into the US as a whole, the 10 most vaccinated states, and the 10 least vaccinated states. The time periods looked at were during Delta’s surge (June 2021 to December 2021) and the initial Omicron surge (December 2021 to March 2022).

The study team then calculated how many potential US deaths could have been averted had the US achieved the same COVID-19 and excess all-cause death rates as its peer countries. Compared to New Zealand, which had a total of 3.7 COVID-19 deaths out of 100,000 and 5.1 out of 100,000 excess all-cause deaths, the US—with a COVID-19 mortality rate of 111.6 out of 100,000 and an excess all-cause death rate of 145.5 out of 100,000–would have avoided 200,663 COVID-19 deaths during Delta and 157,236 deaths during Omicron, for a total of 357,899. It would have avoided 354,910 excess all-cause deaths during Delta and 110,837 during Omicron, for a total of 465,747.

Had the US achieved parity with Austria, which saw a total of 65 out of 100,000 COVID-19 deaths and 72.9 out of 100,000 excess all-cause deaths, the US would have avoided 154,622 total COVID-19 deaths and 240,871 excess all-cause deaths. If the US as a whole mirrored the 10 most vaccinated states, which had 74.7 out of 100,000 COVID-19 deaths overall, 122,304 lives lost to COVID-19 could have been saved. Equally sobering, the researchers calculated that if the entire US followed the trajectory of the 10 least vaccinated states, 114,138 extra people would have died from COVID-19 and 158,922 extra would have perished under the “excess all-cause mortality” heading.

“The US continued to experience significantly higher COVID-19 and excess all-cause mortality compared with peer countries during 2021 and early 2022, a difference accounting for 150,000 to 470,000 deaths,” the authors wrote. “This difference was muted in the 10 states with highest vaccination coverage; remaining gaps may be explained by greater vaccination uptake in peer countries, better vaccination targeting to older age groups, and differences in health and social infrastructure.”

All-cause excess mortality lagged COVID-19 mortality in certain countries such as Sweden, as well as in highly vaccinated US states. The authors posit that this could be due to fewer non-COVID-19 deaths, although it’s difficult to determine whether causes of death were recorded in disparate ways in different locations. An additional limitation of the study was the use of provisional mortality estimates in some circumstances.