Long Covid-19, a condition that affects millions of people’s health and quality of life worldwide, has since spread to a large number of people, costing economies billions of dollars in employee performance losses and labor declines in general.
The extensive clinical research that Covid sparked has resulted in more than 24, 000 scientific papers, making it the most extensively researched medical problem in any four years of human history.
Long Covid is a term used to describe the series of long-term health results brought on by SARS-CoV-2 disease. These range from prolonged respiratory ailments, such as shortness of breath, to debilitating stress or mental cloud that boundaries people’s ability to work, and problems such as heart failure and diabetes, which are known to last a lifetime.
Since the start of the pandemic, I have been deeply immersed in long-term Covid research. I am a physician scientist. I have extensively researched long Covid, testified before the US Senate, and was named one of Time’s 100 most influential people in health in 2024 for my research in this field.
A flurry of reports and scientific papers on long Covid over the first half of 2024 made this complex condition more clear. These include, among other things, new insights into how Covid-19 continues to wreak havoc on many organs years after the initial viral infection, as well as new research on viral persistence and immune dysfunction that persist for months or years after the initial infection.
How long does COVID last on a person’s body?
On July 17, 2024, a new study that my colleagues and I published in the New England Journal of Medicine revealed a decrease in the risk of long Covid over the course of the pandemic.
In 2020, when the ancestral strain of SARS-CoV-2 was dominant and vaccines were not available, about 10.4 % of adults who got Covid-19 developed long Covid. By early 2022, when the omicron family of variants predominated, that rate declined to 7.7 % among unvaccinated adults and 3.5 % of vaccinated adults. In other words, people without vaccinations had twice as much of a chance of developing long Covid.
Researchers like me do not yet have precise figures for the current rate in mid-2024 due to the time it takes for long Covid cases to be reflected in the data, but the flow of new patients into long Covid clinics has been on par with 2022.
We discovered that the decline was brought on by the availability of vaccines and changes in the virus ‘ characteristics, which made it less likely to develop severe acute infections and may have decreased its capacity to survive long enough to lead to chronic disease.
Despite the decline in risk of developing long Covid, even a 3.5 % risk is substantial. Millions of new long Covid cases are created each year as a result of new and repeated Covid-19 infections, which add to the staggering number of people who are affected by this condition.
According to estimates for the first year of the pandemic, at least 65 million people worldwide have experienced long Covid. My team will soon release updated estimates of the global burden of long Covid and its impact on the global economy through 2023, along with a group of other leading scientists.
Additionally, a significant new report from the National Academies of Sciences Engineering and Medicine lists every health effect that goes along with long Covid. The Social Security Administration requested the report to understand the impact of long-term care on the benefits for disabled people.
It comes to the conclusion that long Covid is a multifaceted chronic condition with more than 200 health effects that can be experienced by all body types. These include new onset or worsening:
Long Covid can affect people of all ages, from young children to older adults, as well as people of all races, ethnicities, and baseline health status. Importantly, more than 90 % of people with long Covid had mild Covid-19 infections.
The National Academies ‘ report added that long after an initial infection, a person can be unable to return to work or school, have a bad quality of life, be unable to do daily living activities, or have their physical and cognitive function decline for months or years.
The report points out that many health effects of long Covid, such as post-exertional malaise and chronic fatigue, cognitive impairment and autonomic dysfunction, are not currently captured in the Social Security Administration’s Listing of Impairments, yet may significantly affect an individual’s ability to participate in work or school.
A long road ahead
What’s more, health problems resulting from Covid-19 can last years after the initial infection.
A significant study conducted in the first year of the study’s publication in early 2024 discovered that even people who had a mild SARS-CoV-2 infection still had new health issues related to Covid-19 in the third year after the initial infection.
Similar findings follow other studies that have demonstrated that the virus persists in various organ systems for months or years following Covid-19 infection. And research has shown that immune responses to a mild infection persist for up to three years. Together, these studies may explain why a SARS-CoV-2 infection years ago could still cause new health problems long after the initial infection.
Important progress is also being made in understanding the mechanisms by which long Covid wreaks havoc on the body. Two recent studies from the US and the Netherlands demonstrated that when researchers transfer auto-antibodies, which are directed at a person’s own tissues and organs, from long Covid-like people into healthy mice, the animals begin to experience long Covid-like symptoms like muscle weakness and poor balance.
These studies suggest that long Covid may be caused by an abnormal immune response that is thought to be the source of these auto-antibodies, and that removing these auto-antibodies may have potential as treatments.
An ongoing threat
Despite overwhelming evidence of the extensive risks of Covid-19, a lot of the messaging suggests that it is no longer a threat to the general public. Although there is n’t any empirical proof to support this, the general public has been persuaded by this false information.
The data, however, tells a different story.
More hospitalizations and fatalities are caused by Covid-19 infections than the flu, which still outnumber the number of cases. Covid-19 also leads to more serious long-term health problems. It is untrue to label Covid-19 as an inconsequential cold or to compare it to the flu.
Ziyad Al-Aly is Chief of Research and Development, VA St. Louis Health Care System. Clinical Epidemiologist, Washington University in St. Louis
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