A Big Unknown: Long Covid-19

Welcome to Plugging the Gap (my email newsletter about Covid-19 and its economics). In case you don’t know me, I’m an economist and professor at the University of Toronto. I have written lots of books including, most recently, on Covid-19. You can follow me on Twitter (@joshgans) or subscribe to this email newsletter here. (I am also part of the CDL Rapid Screening Consortium. The views expressed here are my own and should not be taken as representing organisations I work for.)


Last week I met someone who has not had the best pandemic. He contracted Covid in March 2020 and then again in May 2021 (likely the Alpha variant). He is now fully vaccinated. Both of his Covid experiences involved bad symptoms on the edge of going to the hospital and, in each case, his immediate family also contracted the virus. But what was most worrying is that his symptoms have persisted. He has continued to get ‘Covid nails’ which are pussey build-ups on his fingernails along with “attacks” of shooting pains followed by exhaustion that lasts for a couple of days. I must say that he seemed in remarkably good spirits given all this. But the story really impacted on me.

Long Covid is something that has been documented but is not well understood. Here is a very long post from Astral Codex that covers what is currently known. One good take-a-way is that Long Covid seems to be rare in children although the evidence is pre-Delta. So I will “pretend” that is true for the purposes of this post. There is also this piece by Ed Yong that looks at the mixed scientific response to Long Covid.

As I try to think about when we might move from dealing with Covid to living with Covid, one of the big unknowns is what the impact of vaccines are on Long Covid. Vaccines do not protect you from being infected with the coronavirus but they do yield great results in keeping you out of hospital or worse. The problem is that we don’t know how well they protect you against persistent non-mild Covid symptoms. This is important as the current expectation is that the “living with Covid” endgame involves most of us being infected with Covid — likely the Delta variant — before it dies out as a pandemic. We might be able to move to that endgame if the main health risks were hospitalisation or death (as these seem to have been dealt with) but what about Long Covid. It doesn’t seem like having persistent issues would be something that one would want to risk.

What do we know about Long Covid amongst the vaccinated?

Sadly, not much. The problem is the “long” part. We have only recently got vaccines and so there just hasn’t been enough infections amongst the vaccinated, let alone time passed, to assess Long Covid prevalence.

One new British study does suggest that vaccines help. From the NYT:

People who experience breakthrough infections of the coronavirus after being fully vaccinated are about 50 percent less likely to experience long Covid than are unvaccinated people who catch the virus, researchers said in a large new report on British adults.

The study, which was published in The Lancet Infectious Diseases journal on Wednesday, also provides more evidence that the two-shot Pfizer-BioNTech, Moderna and AstraZeneca vaccines offer powerful protection against symptomatic and severe disease.

Here is the relevant chart:

One problem with this study, however, is that “long” wasn’t that long — defined as four weeks after infection. Moreover, the symptoms were self-reported which carries its own issues — although which direction the bias might go is uncertain.

Nonetheless, the chart is pretty encouraging as the long-term symptom drop was higher than almost anything else.

The point, however, is that this remains a big unknown and suggests that we need to wait for more information on Long Covid before transitioning to the expected endgame.

About “waiting for the science”

The problem we face, however, in waiting for the science on Long Covid is that the science is currently in dispute. From Ed Yong:

Long-haulers were the ones who described, defined, and drew attention to their condition: “Patients collectively made long Covid,” two long-haulers, the geographer Felicity Callard and the archaeologist Elisa Perego, wrote in a historical review. Now many feel that their expertise is being ignored and their hard-won knowledge is being excluded from investigations into their own illness. The message seems to be: Thanks for everything; academia can take it from here.

This attitude is slowing down long-COVID research and skewing its focus. Both long-haulers and researchers who work with them have told me about flawed studies that paint an inaccurate picture of the condition, or clinics that are recommending potentially harmful treatments. Many researchers, they argue, are missing the full picture because they’re treating long COVID as a completely new entity, and ignoring telling similarities to other complex illnesses such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

“The interest of the biomedical community is welcome—we wanted their attention!” says Athena Akrami, a neuroscientist at University College London who is part of the Patient-Led Research Collaborative, a group of long-haulers who have been studying their own community. But many academics, as they are wont to do, are contorting questions about long COVID to fit their preexisting research agendas. “In an ideal scenario with infinite resources, scientists could take an intellectual interest in some peculiarity of the condition,” Akrami told me. “But this is the real world, and limited resources need to be distributed according to the needs of patients.”

What to make of this. Yong documents that, a year since Long Covid started to be reported as potentially a thing, academic research has been slow. There is a tension between those who have Long Covid symptoms and their beliefs that academic researchers are not taking it seriously and academic researchers who are sceptical because that is what they tend to be. I can’t parse this tension to say anything meaningful about it.

But it does strike me as exactly the sort of tension between long-standing presumptions in a scientific field versus observations on the ground during the pandemic that have more often than not resolved themselves against the scientific consensus as new information has come to light. In other words, I have some sympathies now with the notion that scientific research can be somewhat stuck in its ways.

Take the above quote that references chronic fatigue syndrome. Scientists have often concluded this is psychosomatic rather than real because they have failed to find causal correlates that explain why one person has it and others don’t. Scientists have noted that Long Covid has symptoms that look alot like chronic fatigue syndrome. The conclusion they have reached is to project their presumptions about that on to Long Covid — that is, to believe that Long Covid may also be psychosomatic.

But I have to wonder, as a layperson it should be emphasised, why this is the likely conclusion to draw. What if that a past viral infection is responsible for chronic fatigue syndrome but it has been hard to identify because we haven’t had a pandemic that has given it to large numbers of people in a short period of time? In that case, might Long Covid be evidence that the cause of all of these other unexplained conditions may itself be a long-lasting impact of a past viral infection that was just never measured or recorded? This is opposed to Long Covid being just another manifestation of a series of unexplained phenomenon that is timed with psychological stress. In my mind, there is surely some possibility that Covid may be the thing that tells us about conditions similar to Long Covid that were previously unexplained rather than being confirmation of the residual explanation when there are unexplained conditions observed.

The point here is that if Long Covid is the thing we need to learn more about, we need scientists to approach it more objectively than they have apparently approached other things about Covid — most notably aerosol transmission that is causing a re-write of all the science on the transmission of respiratory illnesses including influenza. Time is of the essence here.