Chicago Blackhawks’ captain Jonathan Toews announced he is dealing with symptoms of long Covid and what he has describes as a chronic immune response syndrome. Toews missed the entire 2020-21 NHL season due to this syndrome. Though he did return to play in the 2021-2022 season as well as part of the current season, Toews hasn’t played since January 28th. He will now step back from playing hockey to focus on his health.
Another NHL player, Brandon Sutter of the Vancouver Canucks, is also suffering from long Covid. Sutter hasn’t played since 2021.
In the anti-vax community, conspiracy theories abound, suggesting that long Covid, and even death in some cases, are effects of vaccines. Perhaps some of these folks will soon turn to social media and other outlets to blame Toews’ symptoms on the Covid-19 vaccine. But Toews’ (and Sutter’s) long Covid symptoms predate being vaccinated. Toews believes he contracted a fairly severe case of Covid-19 in late February 2020, and has experienced periodic symptoms ever since. Sutter got Covid-19 in March 2021, before he received his first dose of vaccine.
Toews wouldn’t be the first to have experienced long Covid as early as the spring of 2020. By late spring 2020, long Covid had been reported independently in multiple countries. Back then, the clinical literature named persons suffering from persistent Covid symptoms, “long-haulers.”
Clinicians and researchers began tabulating the different sets of lingering Covid-19 symptoms afflicting tens of thousands of patients. These sometimes debilitating symptoms included shortness of breath, extreme fatigue, intermittent fevers, cough, concentration issues, chest pressure, headaches, and heart palpitations.
By the fall of 2020 - again, months before anyone was vaccinated - the existence of a constellation of long Covid symptoms among hundreds of thousands of patients worldwide had been well-established.
This doesn’t mean that in 2020 it was perfectly clear to clinicians how to demarcate long Covid, or that the set of symptoms remained constant from wave to wave or (sub)variant to (sub)variant. Moreover, clinicians found that post-Covid conditions did not affect everyone uniformly.
Gradually, in 2021 more evidence came to light confirming the presence of a still unexplained syndrome. For instance, a University of California Davis study found that 10% of Covid-19 patients suffered from long Covid symptoms. Another study suggested that 30% developed at least one long Covid symptom over time. The discrepancies in percentages could be explained by differences in the populations examined, and the fact that there was no widely accepted definition of long Covid.
Even today, there isn’t a firm consensus on long Covid’s precise definition, and multiple avenues for causality are being explored and investigated by clinical researchers around the globe.
Yet, current research on the topic is both more in-depth and sophisticated than it was early on in the pandemic. In December 2022, a team of researchers at Weill Cornell Medicine published a comprehensive study on long Covid in Nature Medicine. To date, it was the largest of its kind to examine the syndrome.
The researchers delineated four major subtypes of long Covid. The first, which accounted for 34% percent of patients, was dominated by heart, kidney and circulation-related symptoms. Patients in this group, compared with those in other groups, were older (median age 65), had a comparatively high rate of Covid hospitalization (61%) and more pre-existing conditions. This group also had the highest proportion (37%) of patients who contracted the coronavirus during the first U.S. wave from March to June 2020.
The second symptom pattern, impacting 33% of patients, was dominated by respiratory and sleep problems, anxiety, headache, and chest pains. Patients with this pattern were mostly female (63%), with a median age of 51, and a much lower rate (31%) of Covid hospitalization. Nearly two-thirds of the patients in this group tested positive for the coronavirus during later waves, from November 2020 to November 2021. And here, the pre-existing conditions were mainly respiratory issues, such as chronic obstructive pulmonary disorder and asthma.
The other two symptom patterns were dominated, respectively, by musculoskeletal and central nervous system symptoms.
The Cornell study isn’t the only one making the rounds in the academic and clinical community. Last year, a survey by the Centers for Disease Control and Prevention (CDC) estimated that of the 40% or so of Americans who reported a Covid-19 infection, 19% of them went on to develop at least one symptom of long Covid.
These kinds of detailed surveys are also being conducted by CDC counterparts outside the U.S. For example, the Dutch RIVM, which is the country’s CDC, is carrying out a long-term investigation on long Covid. The agency released interim results last summer, which showed that approximately 50% of patients enrolled in the large ongoing study still had one or more symptoms three months after becoming infected with the coronavirus.
The RIVM designed an extensive health survey questionnaire, which was taken by a total of 14,572 participants. 9,166 people filled out the survey shortly after testing positive for SARS-CoV-2. The control group consisted of 5,406 people who tested negative for the coronavirus and applied to take part in the survey, or were invited by letter from the general population. The RIVM requested that all survey participants fill out questionnaires about their health at intervals of three months.
Around 33% of study participants who became infected with coronavirus still suffered from fatigue three months later. Persistent shortness of breath occurred in 16% of respondents, 15% had ongoing brain fog, and 12% had chronic loss of their normal sense of smell and taste for at least three months after their initial infection.
What’s striking is that these reported symptoms are 1.5 times more common among Covid-19 patients than among those who have had other (non Covid-19) respiratory infections.
Given the now mounting evidence that suggests not only long Covid’s existence - albeit variegated - but also its rather profound impact, it’s strange that the term long Covid has become a trigger of sorts for a curious collection of critics, skeptics, and contrarians. There’s the anti-vax community who associate numerous long Covid symptoms with the vaccines. Not only that, they denote vaccines as a causative agent. Then, there is a criticism leveled at long Covid which perhaps can be taken more seriously in that it doesn’t deny its existence or attribute it to the vaccine. Rather, it says the reported prevalence of long Covid is exaggerated and even political.
Though there may indeed be response bias in some of the many reports out there, surely large-scale studies like the ones being conducted by Cornell and the Dutch CDC conform to widely accepted scientific standards. Additionally, it’s hard to detect any political aim whatsoever in the Cornell or Dutch study. They’re observing a pattern, reporting it, and learning as they gather more data.
If there’s any lesson to be drawn from Toews’ leave of absence, or the study findings cited above, it’s that long Covid is a problem that shouldn’t be ignored or downplayed.