Scientists are trying to unravel the puzzle of long COVID. What you need to know

As a result of the intense scientific effort sparked by Long COVID, Over 24,000 scientific publicationsThis is the most studied health period of any four-year period recorded in human history.

Long COVID teeth, A collection of long-term health effects Infection with the SARS-CoV-2 virus can cause a wide range of respiratory symptoms, from persistent shortness of breath, to debilitating fatigue and brain confusion that can limit the ability to work, to conditions such as heart failure and diabetes that are known to last a lifetime.

read more: New long COVID guidelines aim to help doctors identify mental health symptoms

I am a physician-scientist and have been deeply involved in long-term COVID-19 research since the early days of the pandemic. I have testified as a physician before the U.S. Senate. Expert Testimony on Long COVIDhave Has been widely published and, Time Magazine's 100 Most Influential People in Health for 2024 For my research in this field.

In the first half of 2024, A flurry of reports and Scientific Papers Research on long COVID has brought further clarity to this complex condition, particularly insights into how COVID-19 can cause extensive damage to many organs even years after the initial viral infection, as well as emerging evidence of viral persistence and immune dysfunction that can continue for months or years after initial infection.

Early in the pandemic, the SARS-CoV-2 virus seemed to be primarily wreaking havoc on the lungs, but researchers soon realized the virus was affecting many organs in the body. Photo by Benoit Tessier via Reuters

How long will COVID's effects on the body last?

According to a new study my colleagues and I published in the New England Journal of Medicine on July 17, 2024: Risk of Long COVID is Lower The risk of developing long COVID-19 has increased over the course of the pandemic. In 2020, when ancestral strains of SARS-CoV-2 dominated and a vaccine was not available, approximately 10.4% of adults infected with COVID-19 developed long COVID-19. By early 2022, when Omicron family variants became dominant, that rate had fallen to 7.7% in unvaccinated adults and 3.5% in vaccinated adults. In other words, unvaccinated people were more than twice as likely to develop long COVID-19.

read more: Years after the pandemic began, scientists are still trying to understand Long COVID

While researchers like me don’t yet have hard numbers on current rates in mid-2024 because it takes time for long COVID cases to show up in the data, the influx of new patients into long COVID clinics is similar to 2022.

This decline was found to be the result of two main factors: the availability of a vaccine and changes in the characteristics of the virus, which may have made it less likely to cause a severe acute infection and reduced its ability to persist in the human body long enough to cause chronic disease.

Although the risk of developing long COVID is declining, even a 3.5% risk is substantial. New and reinfections with COVID-19 will lead to millions of new long COVID cases, adding to the already staggering numbers of people suffering from the condition.

Estimates for the first year of the pandemic At least 65 million people The world continues to have long COVID-19. My team, along with a group of other leading scientists, will soon be publishing updated estimates of the global burden of long COVID-19 and its impact on the world economy through 2023.

Additionally, a major new report from the National Academies of Sciences, Engineering, and Medicine states: The health effects that make up Long COVIDThe report was commissioned by the Social Security Administration to understand the impact of long COVID-19 on disability benefits.

The report concludes that Long COVID is a complex chronic disease that can cause more than 200 health effects across multiple body systems, including the onset of new and exacerbated conditions.

Long COVID can affect people across the lifespan, from children to the elderly, and across races, ethnicities, and underlying health conditions. Over 90% of long COVID patients He had a mild case of COVID-19.

The National Academy of Sciences report also concludes that long COVID-19 can result in consequences such as an inability to return to work or school, reduced quality of life, reduced ability to perform daily activities, and declines in physical and cognitive functioning for months to years after initial infection.

read more: These 12 symptoms may define long COVID, according to new study

The report found that many of the health effects of long COVID, such as post-exertional malaise, chronic fatigue, cognitive impairment, and autonomic dysfunction, are currently Social Security Administration disability listHowever, it can have a significant impact on an individual's ability to participate in work or school.

Many people experience long-term COVID symptoms for years after initial infection.

long way to go

Additionally, health problems from COVID-19 can last for years after initial infection.

According to a large-scale study published in early 2024, Even mild SARS-CoV-2 infections create new health problems The number of COVID-19-related deaths has increased in the third year since the first infections.

These results are similar to those of other studies, The virus persists After infection with COVID-19, immune responses occur in various organ systems over the course of months to years. Studies have shown that the immune response to infection Still clear after 2-3 years Together, these studies may explain why SARS-CoV-2 infections years ago can cause new health problems long after the initial infection.

clock: Long-term COVID-19 patients describe how the disease has changed their lives

Important progress has also been made in understanding the pathways by which long COVID wreaks havoc on the body. Two preliminary studies From the United States and Netherlands When researchers transferred autoantibodies (antibodies produced by a person's immune system that target their own tissues and organs) from a person with long COVID to healthy mice, the animals showed that they began experiencing symptoms similar to long COVID, such as muscle weakness and poor balance.

These studies suggest that an abnormal immune response, possibly involved in the generation of these autoantibodies, may underlie long COVID. Remove these autoantibodies This may be a promising potential treatment.

An ongoing threat

Despite overwhelming evidence showing the widespread risks of COVID-19, many messages suggest it is no longer a threat to the general public. There is no empirical evidence to support this, but this misinformation has permeated public discourse.

But the data tells a different story.

COVID-19 infected people continue More cases than influenza and, Hospitalizations increase and death COVID-19 is worse than influenza. More serious long-term health problemsDon't think COVID-19 is just a cold or Considered equivalent to influenza It doesn't match reality.

This article is reprinted from conversation Published under a Creative Commons license. Original Article.