What Are We Learning about Long COVID?

Dr. Paul Offit describes three theories related to the causes of post-COVID symptoms in adults. Current theories include continued viral replication, hyperactive immune responses, or blood clotting (specifically microclots) caused by COVID-19 that leads to issues in other parts of the body (e.g., lungs, liver, heart, and kidneys). As he describes, “long COVID” may be an umbrella term that is capturing symptoms being caused by each of these, meaning that different people may need different types of treatments to resolve their symptoms. Treatment possibilities based on these different possible causes are also described.


What are we learning about long COVID?

Paul Offit, MD: Hi, my name is Paul Offit. I'm talking to you today from the Vaccine Education Center at the Children's Hospital of Philadelphia. It's Thursday, December 1st, 2022. I think one of the consequences of the COVID pandemic is something called long COVID, which is to say, people who initially recover from the disease but then go on for one month, two months, three months, four months, one year later, two years later, to continue to have persistent symptoms. And those symptoms can include malaise, listlessness, brain fog where you have problems with memory, fatigue, as well as more serious problems such as problems with heart, lung, liver, brain, kidney. It's a serious problem, and it's a problem we're going to be dealing with for years, if not longer.

So, what do we know about long COVID? What can we say is the cause or causes of long COVID, which I think, frankly, is more than one thing even though it's kind of all under the umbrella of one phrase. I think what we've learned so far is that in some people, it may be that the virus is continuing to reproduce itself, continuing to replicate, in which case an antiviral may be of benefit. And there are actually studies going on now to see whether or not antiviral agents, like Paxlovid, benefit people who have long COVID.

Another problem is that it can be sort of this hyperactive immune system, this dysfunctional, hyperactive immune system. Researchers at the Icahn School of Medicine in New York have identified certain features of the immune system that are, if you will, out of control and causing harm. If that's true and that holds up, and it certainly does seem to be holding up in a number of patients, then medicines that modify the immune system may be of value.

A third possible problem associated with long COVID is so-called clotting, which is you have these sort of microclots, these small clots in blood vessels of the lung, liver, heart, kidney. Because there is a vasculitis, meaning an inflammation of the lining of the blood vessels, and because every organ system has a blood supply, every organ system is at risk. If that's an important part of the disease process, then clot-busting therapies may be of value.

So, I think we're going to learn a lot about long COVID over time. I think we're going to learn a lot about the treatment or treatments of long COVID as we figure out which sort of are the critical parts of the disease process. But it is a serious problem, and I think is going to be with us for many years.

Thank you.

Related Centers and Programs: Vaccine Education Center

Last Reviewed on Dec 16, 2022