Scientists believe lasting symptoms following a coronavirus infection are not a single disorder. So new clinical trials are hunting for a range of solutions.
Three years in, the pandemic mania has settled to a rumbling hum. We’re back to sweating on each other in nightclubs, spluttering out birthday candles, and sharing firm handshakes. Covid-19, while still very much alive, has for most people diminished to an everyday threat, thanks to vaccines and treatments.
It’s only now, over three years into the pandemic, that a consensus on what long Covid is has started to solidify. And what it is, it turns out, is a whole bunch of things. Rather than a single disorder, it’s more likely a smorgasbord of diseases that fall under one big umbrella. That means there likely won’t be a one-size-fits-all treatment either.
What triggers long Covid for you may not be what sets it off for another. Perhaps your long Covid is caused by your immune system turning on you, attacking your body—a phenomenon called autoimmunity. So goes one theory. Or maybe it’s that splinters of the virus are hanging around your body long after the initial infection, keeping your immune system’s engine revved up to the point of exhaustion. Another theory is that SARS-CoV-2 causes long-lasting damage to certain organs or tissues. Maybe it’s that a Covid infection reawakens latent viruses your body has encountered before, such as the Epstein-Barr virus, which causes mononucleosis.
Akiko Iwasaki, an immunologist at Yale University, is running a randomized controlled trial of 100 long Covid patients to investigate whether Pfizer’s antiviral drug, Paxlovid, designed to treat symptomatic Covid, could actually help treat long Covid—a theory that has anecdotal backing from patients. The rationale behind the trial is based on the viral reservoir hypothesis: that Paxlovid could eradicate any lingering remnants of SARS-CoV-2 that have managed to persist despite the body’s immune response.
Other ongoing trials target alternative mechanisms. Some researchers are looking at low-dose naltrexone, a drug normally used to treat opioid addiction, which could treat long Covid by hampering inflammation in the body. In the UK, a trial called Stimulate-ICP is looking at using a blood thinner called rivaroxaban to treat microclots in the blood, as some contend that these cause long Covid by blocking oxygen delivery to tissues in the body.
Iwasaki is hopeful that if her team is successful, their research could shed light on other long-overlooked chronic illnesses. “If we can figure out something about long Covid, we might be able to help people with ME/CFS [chronic fatigue syndrome], and other diseases that are related,” says Iwasaki. It could be that they share mechanisms.
What’s crucial is that long Covid doesn’t meet the fate of many other chronic illnesses and end up being grossly neglected—often due in part to the sheer complexity of figuring out their root causes. While many people are returning to their normal lives, we can’t forget about long Covid, says Geng. “There’s still many, many, many people suffering, not able to work, not able to live their normal lives.”
The ME Association comment
“Nothing really new in this review of the possible causes and treatments under investigation for the treatment of Long Covid. The link to ME/CFS is briefly acknowledged:
“Iwasaki is hopeful that if her team is successful, their research could shed light on other long-overlooked chronic illnesses. “If we can figure out something about long Covid, we might be able to help people with ME/CFS [chronic fatigue syndrome], and other diseases that are related,” says Iwasaki. It could be that they share mechanisms.””
What’s crucial is that long Covid doesn’t meet the fate of other chronic illnesses and end up being grossly neglected – often due to the sheer complexity of figuring out the root causes.”
Dr Charles Shepherd,
Trustee and Hon. Medical Adviser to the ME Association.