1 In 3 Americans Had Covid By The End Of 2020, Models Estimate—That’s Four Times The Official Count

According to new research published in Nature on Thursday, around one-third of Americans were infected by Covid-19 by 2020. This suggests that the virus has spread far more widely than official testing and highlights the failures of early U.S. testing programs.

Models show that Covid-19 was caught by many more Americans in 2020 than official tests suggest. AFP via Getty Images

The Key Facts

According to Columbia University models, around 103 million Americans31% had been infected by Covid-19 by 2020. These numbers were based on data from population, recorded cases and people who tested positive for coronavirus antibodies. This number is much higher than the confirmed cases. CDC data shows that this figure is around 20.5million. Researchers believe that only 22% of all infections are caused by Covid-19. Jeffrey Shaman, Columbia University professor of environmental health sciences and one of the paper's authors, stated that the virus spreads faster than what is confirmed by testing. The researchers estimated that more than 60% of those living in the Mississippi valley, Minnesota and Wisconsin will have contracted Covid-19 by 2020. The researchers found that several metropolitan areas had high levels of infection, including Los Angeles (52%), Chicago (48%), New York City (44%), and Miami (42%).

Important Background

A means to detect any disease is one of the most crucial tools for controlling its spread. Despite being in the best position to detect it, the U.S. failed. Its testing program was plagued by logistical, technical, and leadership problems. According to the model, 90% of cases weren't confirmed by testing in March last year. Only 25% were confirmed by the end. Officials are keen to increase testing capacity as the number of cases in the United States continues to rise due to the spread of the highly infectious delta virus.

Big Number

1 in 130. According to the researchers' model, that is how many Americans were infected with Covid-19 December 31. Researchers wrote that a similar percentage was likely to have been infected, but they were not yet contagious.

Important Quote

Although the landscape has changed over time with vaccines available and new variants being spread, it is still important to remember how deadly the pandemic was during its initial year, according to Sen Pei, a Columbia University assistant professor of environmental health sciences.

What we don't know

This model didn't account for people infected by Covid-19 multiple times, waning immunity, and contagious new variants. These factors all contribute to the spread of the virus. These findings can also be retrospectively estimated and therefore cannot be confirmed.

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Nature - 2020: Characteristics and Burden of COVID-19 in America

The Lost Month: How the U.S. was blinded by a failure to test (NYT).

What went wrong in coronavirus testing at the U.S.

How the Pandemic Destroyed America (Atlantic).

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