Two years after the World Health Organization declared the coronavirus a global pandemic, new research suggests around 18.2 million people have died worldwide as a result. That toll is more than three times higher than the WHO’s tally of nearly 6 million officially reported COVID-19 deaths through the end of 2021.
Some 1.13 million Americans have died due to the pandemic, the researchers estimate. By comparison, the current total of reported COVID-19 deaths in the U.S. stands at around 960,000.
The new figures, published Thursday in The Lancet, are based on the number of “excess deaths” in countries around the world. Researchers determined how many additional deaths occurred from January 1, 2020 through December 31, 2021 by modeling the number of “expected” deaths in years unaffected by a global pandemic, compared to the total number who actually died from any cause.
The estimate predates the Omicron variant’s peak in many countries, which drove large waves of deaths in the U.S. and elsewhere over the past few months.
Many of the additional deaths over the past two years can be directly linked to cases of COVID-19. However, the study’s authors say a variety of other factors — ranging from underreporting of infections to the disease’s strain on hospitals — may account for the unprecedented number of additional deaths during the pandemic.
“Further research will help to reveal how many deaths were caused directly by COVID-19, and how many occurred as an indirect result of the pandemic,” the Institute for Health Metrics and Evaluation’s Dr. Haidong Wang, the paper’s lead author, said in a release.
While the U.S. overall does not rank among the nations with the world’s worst rates of excess mortality, it does have one of the largest total numbers of excess deaths in the study. The pandemic’s biggest cumulative toll came from India, the U.S., Russia, Mexico, Brazil, Indonesia and Pakistan.
“These seven countries accounted for more than half of the global excess deaths due to COVID-19 over the 24-month period,” the study’s authors wrote.
Researchers noted that some southern U.S. states ranked among the world’s worst excess mortality rates from COVID-19.
For every 100,000 residents, an estimated 329.7 additional deaths occurred in Mississippi during the pandemic, the highest of any state. In the study’s global estimates, only 21 nations exceeded 300 excess deaths per 100,000 citizens.
More than 12,000 residents of Mississippi have died from COVID-19, according to the Centers for Disease Control and Prevention’s official tally, the most per capita of any state.
“I think this paper highlights the importance of using excess deaths in the analysis of the effects of any sort of pandemic or epidemic like this, in order to get a sense of the true, complete impact,” says Robert Anderson, chief of the CDC’s mortality statistics branch.
The study published Thursday echoes similar figures that have been generated by Anderson’s team, which has been calculating excess deaths on a weekly basis throughout the pandemic in the U.S.
“You see for some of these countries, there are very few numbers of COVID deaths but quite large numbers of excess deaths. That doesn’t suffer from errors in cause of death certification. A death is a death, and it’s pretty easy to tell if people are dead even if it’s not that easy to tell what they died from,” Anderson said.
Based on data through January 2022, the CDC’s own estimate of excess deaths during the pandemic passed 1 million earlier this year. Other ongoing research by the agency suggests the number of Americans who have been infected by the coronavirus could be double that of official reports.
The CDC’s current excess deaths figure may include some fatalities from other disasters that occurred during the past two years, Anderson noted, like the winter storm in Texas that led to crippling blackouts. However, the vast majority of additional deaths have come from COVID-19 cases, which ranks among the country’s leading causes of death.
The agency has also seen substantial swings in other causes of death over the past two years, which might also be linked to the virus or its ripple effects.
Deaths from heart attacks and stroke have climbed beyond pre-pandemic levels, Anderson cited as examples, as well as deaths from dementia and Alzheimer’s disease. COVID-19 has been linked to both cardiovascular and neurological issues, as well as disrupting the ability of doctors to care for non-COVID patients during surges.
“We’ve seen some decline in chronic obstructive pulmonary disease deaths, and that may be related to the pandemic as well. These people are generally at high-risk for serious effects of COVID, and so it’s possible they may have died otherwise without the pandemic as a result of COPD,” said Anderson.
Looking ahead, Anderson said the CDC planned to continue to regularly release data but may soon wind down the resource-intensive weekly estimates it has been publishing on excess deaths in the pandemic.
Anderson predicted the agency may eventually begin to account for some COVID-19 deaths as part of the expected baseline deaths every year. The CDC already analyzes changes in mortality with flu and other endemic diseases, compared to expected deaths.
Given the length of the pandemic so far, Anderson’s team had to tweak their algorithm last year to stabilize their estimates, incorporating additional pre-pandemic historical data.
“When we’re modeling these data to try to get at how many deaths would have occurred in a ‘normal’ year, you have to model a certain number of years of data. And of course, you don’t want to include the data of the non-normal years in the model,” said Anderson.
CBS News reporter covering public health and the pandemic.