Following any bout of coronavirus disease 2019 (COVID-19), regardless of the illness’s severity, many individuals report that specific symptoms persist for months or years. This prolonged experience is commonly referred to as long COVID or post- COVID-19 syndrome. In medical terms, it is referred to as post-infectious autoimmune diseases. Some may also know it as long-haul COVID or post-acute sequelae of SARS-CoV-2 (PASC).
Currently, there is no universally accepted definition of long COVID, highlighting the complexity and evolving understanding of this condition. In the United States, many experts characterize long COVID as a persistent, chronic condition that is triggered by the virus responsible for COVID-19. The clinical terminology for this phenomenon is an infection-associated chronic condition. That means post-infection, the individual immune system consistently attacks the infected or mimics the antigen.
As researchers continue to investigate the nuances and implications of long COVID, the definitions and understandings will likely evolve, reflecting our growing knowledge of this multifaceted illness in the advanced medical world.
Individuals can experience long COVID symptoms after being infected with the COVID-19 virus, even if they did not show any initial signs of illness. Remarkably, these lingering effects can appear weeks, months, or even years after a person seems to have fully recovered from the acute phase of the virus. The continued inflammation, caused by the virus or damaged tissue, triggers the immune system to remain active, resulting in ongoing symptoms with no apparent end in sight.
The virus that causes COVID-19 triggers the immune system’s response to the antigens, including the virus and the virus-caused damaged cells. This could lead immune cells to mistake the body’s cells as a threat and react to them (mimic antigens), a phenomenon known as an autoimmune reaction. The result of long- COVID is an autoimmune disease caused by a viral infection.
The long-COVID symptoms are complicated and depend on individual situations, which can cause different symptoms and varying organ damage. The symptoms and organ damage cannot replace the function of the damaged organ; as a result, advanced medicine has no practical treatment approach for it so far.
