Since the pandemic began, there have been wide-ranging estimates about COVID-19 mortality — what percentage of those who have contracted the virus have not survived. Until recently, public health researchers have not had sufficient information to address the question with precision. After nearly four years, though, we have truly useful data.
So, what is the mortality of COVID-19?
It takes not one figure, but three, to answer that question. All three mortality figures involve assumptions, and the numbers change over time, but patterns are emerging. All three figures employ the total number of U.S. COVID-19 deaths as the numerator. (Caution: There will be math, but only long division. The numerator is the top number.)
Since January 2020, according to data compiled by Worldometer, there have been roughly 1.1 million to 1.2 million U.S. COVID-19 deaths. Some experts doubt that figure, claiming deaths from COVID-19 should be distinguished from deaths with COVID-19 (such as the person who dies in a motorcycle accident who tests positive at the hospital). It’s a fair criticism, and a reasonable estimate is that deaths with COVID-19 account for 10% of the total figure.
However, it is likely that perhaps 10% of people who died from COVID-19 were never tested — those who died at home or died suddenly. A workable assumption is that those who died with COVID-19 and those who were never tested but died of COVID-19 cancel out. The number of COVID-19 deaths, 1.1 million to 1.2 million Americans over the course of the pandemic, is a reasonable estimate.
The other half of the mortality equation is the denominator or bottom number: the number of COVID-19 cases. Because case numbers change over time, COVID-19 mortality cannot be described by a single figure. Each of the three figures describes how dangerous COVID-19 is and the likelihood of death in an individual person who contracts COVID-19.
The first mortality figure is the case fatality rate, the ratio of COVID-19 deaths divided by reported cases of COVID-19. There have been approximately 108.5 million reported U.S. COVID-19 cases. This number increases as more people are diagnosed.
The cumulative case fatality rate of COVID-19 in the U.S. (deaths divided by reported cases) since the pandemic began in January 2020 is 1.05% to 1.10% (1.1 million to 1.2 million divided by 108.5 million).
Basically, from January 2020 until today, if you had a reported case of COVID-19 in the U.S., your chances of dying were a little more than 1 in 100.
The number of actual cases is obviously greater than the number of reported cases, and 108.5 million is a significant undercount, since many COVID-19 cases are never reported due to home testing or lack of testing. The true number can’t be measured definitively, but based on several variables, we can make a decent estimate. The current assumption is that 90% of the U.S. populace of 334 million has had at least one COVID-19 infection. For convenience of computation, about 300 million is the case estimate.
The second mortality number is the infection fatality rate, the ratio of deaths divided by the number of estimated actual cases.
The infection fatality rate of COVID-19 in the U.S. (deaths divided by total estimated cases) since January 2020 is 0.36% to 0.40% (1.1 million to 1.2 million divided by 300 million).
That is, if you had a COVID-19 infection, reported or not, your chances of dying were 3 to 4 in 1,000. Home-tested and unreported cases were less likely to die, explaining the lower figure than the case fatality rate.
The third mortality number is called crude mortality, the number of confirmed deaths divided by the entire population of the US. It includes everyone, including those who have not had COVID-19.
The current crude mortality of COVID-19 in the U.S. (deaths divided by total population) is 0.33% to 0.36% (1.1 million to 1.2 million divided by 334 million).
Bottom line: The chance any person in the U.S. would die of COVID-19 since the beginning of the pandemic is roughly 1 in 300. This is the best number to compare between countries. The crude mortality worldwide is roughly 0.09%, one-quarter that of the U.S. — the U.S. is a high-risk country because of our population’s advanced age and existing health conditions such as obesity.
However, there are three caveats to this data.
First, the case fatality and infection fatality rates — the chances an individual with COVID-19 will die — have been dropping dramatically since the pandemic began. The rates were much higher in 2020 than today and have been falling continuously, likely due to acquired population immunity, vaccination, the sickest having died and the arrival of possibly less severe variants.
The current U.S. infection fatality rate, 0.4% on the high end since the pandemic began, is probably now about 0.1% for new cases, one-third to one-quarter the cumulative number. A random patient with COVID-19 today has a 1-in-1,000 chance of dying, roughly the same as having moderately severe flu.
Second, these average figures do not account for individual risk or vaccination status. The figure for a low-risk patient today may be one-tenth to one-one-hundredth as low: 0.01% to 0.001% — a chance of dying of 1 in 10,000 to 1 in 100,000 — in the neighborhood of having mild flu.
Finally, these figures pertain only to mortality, not to long COVID-19, an important question in which the relative risks are still being studied.
The current figures put COVID-19 mortality into perspective against influenza. In terms of mortality, at its height in 2020-21, COVID-19 was far more severe than most influenza strains, especially in high-risk COVID-19 patients, although never as severe as the 1918-19 flu pandemic.
Today, for high-risk patients, COVID-19 is still more severe than most strains of influenza, but for low-risk patients, COVID-19 mortality has approached that of the average annual flu.
Dr. Cory Franklin is a retired intensive care physician.
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