Once upon a time, it seemed that once you recovered from Covid-19, you were home free—that experiencing the disease might be terrible, but surviving it meant you were done with it. Now we know that’s not the case, as it’s become clear that a growing number of Covid-19 survivors are experiencing long-term effects—known as “long Covid” (formally Post-Acute Sequelae of SARS-CoV-2 or PASC)—even after the virus is ostensibly out of their bodies. What’s more, these “long haulers” are not a small group: studies are showing that, given the vast number of people who have survived Covid-19 globally, it could actually be in the millions.
A survey earlier this month from the Office for National Statistics in Britain polled more than 20,000 participants who’d tested positive for Covid-19 in the last year and found that one in five survivors reported having symptoms after five weeks—and at 12 weeks, the number was still 13.7% (almost one in seven people). The most common symptoms experienced at five weeks were fatigue (11.8%), cough (11%), headache (10%), and muscle pain (7.7%). (Loss of taste and smell followed, each affecting about 6.3% of participants.) At 12 weeks, the prevalence of symptoms was slightly lower, but still distributed similarly and much higher than a control group who hadn’t had Covid-19.
In terms of the big picture, when the authors extrapolated the numbers to the whole of the UK, they suggest that more than a million residents may have experienced long Covid by the beginning of March 2021.
Studies have also shown the striking array of acute effects the coronavirus can have on the body and its organ systems, from cardiovascular to pulmonary to neurological-psychological to kidney and more. That Covid-19 is now considered a multi-organ disease may translate to a wider spectrum of long Covid symptoms than previously understood.
In fact, a new study from researchers at hospitals around the country found that long Covid symptoms included fatigue, shortness of breath, brain fog, loss of sense of smell or taste, anxiety, depression, post-traumatic stress disorder, headache/migraine, and non-restorative sleep. The authors offer guidelines on how to treat patients with long Covid, and urge a multidisciplinary approach to support both the physical and the mental health of those living with long Covid.
“Covid-19 is the first infectious disease that I’ve come across that has such an effect on a wide variety of organs. It’s changed my clinical practice,” said Columbia University’s Elaine Y. Wan in a statement. “No matter what the patient comes in for, I now ask if they ever had Covid-19. It changes the possible range of diagnoses.”
While it seems that people with more severe Covid-19, especially those who were hospitalized, are at higher risk for long Covid (a study from Wuhan found that after six months, three-quarters of these patients still had at least one symptom), this doesn’t mean that people with mild illness are off the hook. A study out last week from the Karolinska Institute reported that among a group of healthcare workers who’d had mild Covid-19, 10% still had at least one symptom severe enough to impact their work, home, or social lives eight months later (the most common symptoms were loss of smell and taste, fatigue, and respiratory problems). While the study was quite small and the results should be interpreted with some caution, other studies have also suggested that even mild initial illness can lead to long-term effects.
It’s not totally clear what causes long Covid, or any post-viral syndrome, for that matter, including chronic fatigue syndrome/myalgic encephalomyelitis. It may be that remnants of the virus are left in the body or that symptoms are due to damage from the body’s own immune response—and/or the fact that it may just take a long time to repair the various levels of injury caused by the acute phase of the illness. There’s some early suggestion that the Covid-19 vaccine reduces symptoms in long haulers, most in the form of anecdotal evidence and surveys, not yet in peer-reviewed studies. One in-the-works study found that after vaccination, long Covid symptoms resolved in over 20% of participants, and some suggest it may be even higher.
Luckily, more research is being done and will hopefully shed additional light on the prevalence of long Covid, whether it gets better over time, and what treatments may be help alleviate it. And hopefully patients will be taken seriously and treated sensitively by the medical community, and that the sheer number of people experiencing long Covid will prompt more resources and more research to understand it.