A comprehensive study conducted by researchers from the Universities of Arizona, Oxford, and Leeds has provided critical insights into long COVID, a condition also known as post-COVID-19 syndrome.
This analysis, which examined dozens of previous studies, sheds light on the number and range of people affected, the underlying disease mechanisms, the numerous symptoms developed by patients, and the current and potential future treatments for the condition.
Long COVID is characterized by symptoms that persist for three months or longer following an acute COVID-19 infection. The illness can impact multiple organ systems, leading to reduced functionality and a range of symptoms, including fatigue, cognitive impairment (often referred to as 'brain fog'), breathing difficulties, and physical discomfort.
The condition can affect almost anyone, regardless of age, including children. However, it is more commonly observed in females and those from lower socioeconomic backgrounds. The reasons for these differences are still under investigation. The study also found that while some individuals gradually recover from long COVID, others may continue to suffer from its effects for years. Alarmingly, many people who developed long COVID before vaccines became available are still unwell.
"Long COVID is a devastating disease with a profound human toll and socioeconomic impact," stated Dr. Janko Nikolich, senior author of the study, director of the Aegis Consortium at the University of Arizona Health Sciences, and professor and head of the Department of Immunobiology at the University of Arizona College of Medicine - Tucson. He added, "By studying it in detail, we hope to both understand the mechanisms and find targets for therapy against this condition and potentially other infection-associated chronic conditions like myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia."
According to the Centers for Disease Control and Prevention (CDC), long COVID affects an estimated 4%-10% of the U.S. adult population, with approximately 1 in 10 adults who had COVID developing long COVID. Globally, 3%-5% of people still develop long COVID after an acute infection, even if they have been fully vaccinated and up-to-date with boosters.
The review highlighted a wide range of biological mechanisms involved in long COVID, including the persistence of the original virus in the body, disruption of the normal immune response, and microscopic blood clotting. These mechanisms were observed even in individuals who had only mild initial infections.
Currently, there are no proven treatments for long COVID. Management of the condition focuses on symptom relief and rehabilitation. Researchers emphasize the urgent need to develop and test biomarkers, such as blood tests, to diagnose and monitor long COVID. Additionally, there is a critical need to find therapies that address the root causes of the disease.
To reduce the risk of developing long COVID, experts recommend avoiding COVID-19 infection through preventive measures such as wearing close-fitting masks in crowded indoor spaces, taking antivirals promptly if infected, avoiding strenuous exercise during the infection, and staying current with COVID-19 vaccines and boosters.
"Long COVID is a dismal condition, but there are grounds for cautious optimism," said Trisha Greenhalgh, lead author of the study and professor at Oxford's Nuffield Department of Primary Care Health Sciences. "Various mechanism-based treatments are being tested in research trials. If proven effective, these would allow us to target particular subgroups of people with precision therapies. Treatments aside, it is becoming increasingly clear that long COVID places an enormous social and economic burden on individuals, families, and society. In particular, we 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 often been turned upside down."
This extensive review underscores the complexity of long COVID and the need for continued research and targeted interventions to alleviate its impact on affected individuals and society at large.
