In a new review paper, researchers from the Universities of Arizona, Oxford, and Leeds analyzed numerous previous studies on long COVID to explore the number and variety of people affected, the underlying mechanisms of the disease, the various symptoms that patients develop, and current and future treatments. Long COVID, also known as Post-COVID-19 condition, is generally defined as symptoms persisting for three months or more after acute COVID-19. This condition can affect and damage many organ systems, leading to severe and long-term impaired function and a broad range of symptoms, including fatigue, cognitive impairment, breathlessness, and pain. The researchers found that while some people gradually recover from long COVID, for others, the condition can persist for years, leaving them unwell even after the advent of vaccines.
Long COVID can affect almost anyone, including all age groups and children, but is more prevalent in females and those of lower socioeconomic status. The reasons for these differences are still under investigation. According to CDC estimates, 4%-10% of the U.S. adult population and 1 in 10 adults who had COVID develop long COVID. The risk of long COVID is much lower for individuals who have been fully vaccinated and are up to date with their boosters. Nevertheless, 3%-5% of people worldwide still develop long COVID after an acute COVID-19 infection. The review study also found that a wide range of biological mechanisms are involved in long COVID, including the persistence of the original virus in the body, disruption of the normal immune response, and microscopic blood clotting, even in some people who had only mild initial infections.
There are currently no proven treatments for long COVID, and the management of the condition focuses on ways to relieve symptoms or provide rehabilitation. Researchers emphasize the urgent need to develop and test biomarkers such as blood tests to diagnose and monitor long COVID, as well as to find therapies that address the root causes of the disease. People can lower their risk of developing long COVID by avoiding infection through measures such as wearing a close-fitting mask in crowded indoor spaces, taking antivirals promptly if they do catch COVID-19, avoiding strenuous exercise during such infections, and ensuring they are up to date with COVID vaccines and boosters.
Despite the lack of proven treatments, the researchers are cautiously optimistic about potential advancements in addressing long COVID. Various mechanism-based treatments are being tested in research trials, which could allow for precision therapies targeting specific subgroups of people. It is also becoming increasingly clear that long COVID places a significant social and economic burden on individuals, families, and society as a whole. There is a pressing need to find better ways to treat and support the ‘long-haulers’—people who have been unwell for two years or more and whose lives have been greatly impacted. The full paper, “Long COVID: a clinical update,” is published in The Lancet, underscoring the importance of continued research and efforts to address the devastating impact of long COVID on individuals around the world.