Long COVID is real. Now the evidence is piling up

A more realistic hope is that researchers can one day offer physicians a kind of “how to” manual for long COVID with a battery of tests to pinpoint what’s gone wrong and, ideally, treatments. The new study is an important step towards that goal, and should offer patients needed hope that answers could be on the way.

In what the researchers believe is a first, they did a detailed study of the differences between people with long COVID and those who are healthy (a mix of those who never had COVID and those who recovered from their infection). They wisely excluded anyone who had been hospitalized with COVID, so as not to confuse explainable lingering symptoms—for example, those caused by lung damage following a week of intubation — with the more mysterious ones that follow a mild infection.

When they compared an exhaustive list of measurements, a few stood out as being distinct features of long COVID. Among the strongest signal: Many people with long COVID had much lower levels of cortisol, which regulates our sense of alertness. In a healthy person, the stress hormone hits a nadir around midnight, then rises to a peak somewhere between 6am and 8am. That lack of cortisol could help explain the bone-crushing fatigue experienced by some people with long COVID.

The researchers are already working to understand the root cause of that hormone imbalance, work that ultimately should point to treatment strategies.

They also observed key differences in immune responses. People with long COVID showed signs of B-cell activation and T-cell exhaustion, indications that the body has been fighting something for a very long time, Putrino says.

That result lends credence to one theory about the cause of long COVID: Some people never fully clear the virus. Their immune system keeps reacting to what it perceives as a threat — for months on end. Researchers are now running clinical trials to see if treating people with longer courses of Pfizer’s antiviral Paxlovid could get rid of that lingering virus and help people feel better.

The last big finding was that in some people with long COVID, other latent viruses — things like Epstein Barr virus that go dormant, but don’t disappear — were reactivated. One theory is that the immune system, exhausted by COVID, starts losing its ability to keep those latent viruses at bay, too.

None of these signals should be taken as the arrival of a simple test for the chronic condition. But that doesn’t mean the findings aren’t good news for the millions of people struggling with long COVID. While not quite the comprehensive diagnostic toolkit many would like now, this short list still could be useful. Doctors can very easily run a full hormone panel to look for dysregulation and also test for evidence of latent virus reactivation, Putrino says.

And Putrino suggests more data will come soon. Moreover, this kind of research should become a template for studying other mysterious long-haul conditions, like ME/CFS, known more commonly as chronic fatigue syndrome, or long Lyme disease.

Finally, the work offers concrete, biological evidence that long COVID is real. That gives people with long COVID a helpful rejoinder to the skeptics who believe their condition is exaggerated or simply in their heads.

It’s important progress for the millions whose lives have been interrupted by chronic symptoms. And it’s a necessary step to finding cures.

Javier Blas is a Bloomberg Opinion columnist covering energy and commodities. Views are personal, and do not represent the stand of this publication. 

Credit: Bloomberg