7% of U.S. adults had long COVID, find new studies

About 7% of all U.S. adults have experienced long COVID, according to new studies seeking to identify the scope of the problem and define the condition.

Women are more likely to have long COVID—8.6% vs 5.1%, one study found. Race, ethnicity, income, and geographic location also impact the likelihood of having the condition, the research showed.

The studies also found that up-to-date vaccination reduces the likelihood a person will have long COVID.

A 264-page report released June 5 by the National Academies of Sciences, Engineering, and Medicine (NASEM) was commissioned by the Social Security Administration to determine the long-term effects of COVID-19 and its potential impact on disability. NASEM followed this with a June 11 report on defining long COVID for the benefit of “policymakers, researchers, public health professionals, clinicians, support services, and patients.”

Another long COVID study, based on a survey of 17,418 adults and sponsored by the Agency for Healthcare Research and Quality (AHRQ), was published June 7.

What is long COVID?

“Long COVID (LC) is an infection-associated chronic condition (IACC) that occurs after SARS-CoV-2 infection and is present for at least 3 months as a continuous, relapsing and remitting, or progressive disease state that affects one or more organ systems,” according to NASEM’s report. However, this is not meant to be “the final word” as further research can expand and refine the definition, NASEM said.

“The lack of a consistent definition for long COVID has hampered research and delayed diagnosis and care for patients,” said Harvey Fineberg, president of the Gordon and Betty Moore Foundation, and chair of the authoring committee. “Our committee hopes this single definition, crafted with input from across research and patient communities, will help to educate the public about this widespread and highly consequential disease state.”

The AHRQ-sponsored Medical Expenditure Panel Survey (MEPS) used the Centers for Disease Control and Prevention (CDC) definition that long COVID “represents many potentially overlapping entities, likely with different biological causes and different sets of risk factors and outcomes.”

The survey found Hispanic and white adults had higher rates of long COVID than Asian and Black adults. Asian adults, who were shown to have the highest level of updated shots, have long COVID at a rate of 3.3%.

Respondents who received updated COVID-19 shots reported a lower rate of long COVID (5.8%) compared to 8.7% for those receiving only the primary vaccine series and 8.4% for those who’d never been vaccinated, AHRQ reported.

The impacts of long COVID

NASEM’s report on the extent and impacts of long COVID highlighted nine key findings:

1. “Long COVID is a complex chronic condition caused by SARSCoV-2 infection that affects multiple body systems.” The extent of people with the condition is difficult to define because of variable testing and inadequate reporting, but having tested positive for COVID-19 is not a prerequisite for having long COVID.
2. “The risk of Long COVID increases with the severity of acute infection.” Those whose infection required hospitalization “are 2–3 times more likely to experience long COVID than are those who were not hospitalized.”
3. “Long COVID is associated with a wide range of new or worsening health conditions impacting multiple organ systems.” There are more than 200 long COVID symptoms and each person can be affected differently.
4. “Long COVID can result in the inability to return to work (or school for children and adolescents), poor quality of life, diminished ability to perform activities of daily living, and decreased physical and cognitive function for 6 months to 2 years or longer after the resolution of acute infection.” Impairments can include post-exertional malaise and chronic fatigue, post-COVID-19 cognitive impairment, and autonomic dysfunction.
5. ”Although the large majority of children recover fully from SARSCoV-2 infection, some develop Long COVID and experience persistent or intermittent symptoms that can reduce their quality of life and result in increased school absences.” The trajectory for children is still better than that for adults.
6. “There currently is no curative treatment for Long COVID itself.” Management of the condition currently involves treating associated health impacts and complications.
7. “Recovery from Long COVID varies among individuals, and data on recovery trajectories are rapidly evolving.” While not conclusive, the data suggests those with long COVID three months after infection improve by 12 months. “Preliminary data suggest that recovery may plateau or progress at a slower rate after 12 months.”
8. “Social determinants of health, such as socioeconomic status, geographic location, health literacy, and race and ethnicity, affect access to health care.” The challenges of receiving specialized care tend to increase health disparities.
9. “Complex, infection-associated chronic conditions affecting multiple body systems are not new, and Long COVID shares many features with such conditions as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia, and postural orthostatic tachycardia syndrome.”

The Biotechnology Innovation Organization (BIO) has partnered with a patient group for ME/CFS in an effort to encourage study into long COVID and its possible connection to other post-infection conditions.