The United States has been in a "protracted health crisis" for decades, the researchers say.
Plaque growth can lead to a higher risk of heart attack, stroke, and other life-threatening cardiovascular events for as long as 1 year.
Post-exertional malaise, or exercise intolerance, was seen in 36% of those with long COVID.
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The most-cited reasons for not getting new COVID-19 boosters were lack of awareness about eligibility and overestimations of their own existing immunity.
The authors say the findings indicate that the protection conferred by previous infection should not detract from the need for vaccination.
Risk factors for persistent symptoms at 28 days included being unvaccinated at infection, moderate or severe acute illness, longer hospital stays, and underlying health conditions.
Within the first 21 days after diagnosis, the risk of all-cause death was 68 to 81 times higher in COVID-19 patients.
Poor outcomes include illness and death, bacterial infections, more ICU days, and serious conditions such as preeclampsia.
The number of affected COVID-19 survivors is based on the estimated global rate of 10% of infected people and more than 651 million documented cases and is likely an undercount.
The WHO welcomed the new details, but asked for a breakdown by province and more SARS-CoV-2 sequences.
Follow-up investigations in the US and other nations and by the company have not found the same increase.
ICU care for COVID-19 patients averaged $24,200, compared with $4,700 for general-admission patients.
Compared with uninfected pregnant women, the risk of death was more than 7 times higher, and the risk of ICU care was almost quadruple.
