Stanford medical specialists tackle long-COVID and its public implications

Jan. 2, 2022, 9:06 p.m.

For some people, COVID-19 symptoms can persist well beyond their initial recovery from the illness. Months after contracting the virus, a COVID-19 survivor can still experience symptoms of discomfort and exhaustion that hinder their return to a pre-COVID routine, Stanford researchers said. 

While post-viral symptoms are nothing new, the issue has come into the limelight because of the widespread nature of COVID-19.

“It’s not surprising that COVID has caused this post-viral syndrome. Post-viral symptoms have been known and described for many other infections as well,” said Hector Bonilla, clinical associate professor of infectious diseases, adding that Herpes and Epstein-Barr are examples of viruses that have long-lasting symptoms.

In May, Stanford Health Care’s Post-Acute COVID-19 Syndrome Clinic (PACS) opened to specifically treat patients with this new condition described as post-COVID-19, more commonly known as long-COVID. 

The co-directors of the PACS Clinic, Bonilla and Linda Geng, clinical assistant professor of medicine, are experts in post-viral syndromes.   

For long-COVID, the severity of the initial illness does not necessarily predict or correlate with the likelihood of developing post-COVID conditions, according to Geng. 

“There is a propensity for acute COVID-19 to be very severe for the elderly population with certain risk factors. However, the population most at risk for long-COVID can include younger patients,” she said. 

According to Geng, the average patient with long-COVID is in their 30s or 40s, and there is a higher percentage of females being treated for long-COVID at the PACS Clinic. 

In terms of how common long-COVID is, study reports vary. 

“The prevalence in the general population is around 1.5%, but for hospitalized COVID-19 patients, the range can go from 30 to 50%,” Bonilla said. 

For hospitalized COVID-19 patients, the conservative estimate is around 10 to 20%, but there are studies reporting as high as 70 to 80%, according to Geng. A Stanford School of Medicine study published in the Journal of the American Medical Association Network Open estimated the prevalence of long-COVID for hospitalized COVID-19 patients to be more than 70%. 

Geng added that the varying findings mean that some of the symptoms may not be severe enough to be brought to attention, which leads to underdiagnosis of long-COVID.

Symptoms of long-COVID are complex. Although most commonly reported symptoms by patients include fatigue and shortness of breath, Geng noted that many have multi-system symptoms that simultaneously appear in respiratory, cardiovascular, neurological and cognitive regions. Bonilla also emphasized the importance of recognizing the varying definitions of long-COVID. While some professionals define long-COVID as symptoms lasting for 30 days, others define it as lasting more than 12 weeks.

With a wide time range of prolonged symptoms, Geng emphasized that patients need to monitor themselves after they have had a COVID-19 infection, and she urges them not to be afraid to raise these symptoms with their physician.

As long-COVID is an active area of ongoing research, much remains unknown. Bonilla emphasized the importance of vaccines, as more research is needed in understanding the effects of long-COVID.

“A study done in the UK showed that vaccination decreased COVID-19 symptoms and the prevalence of long-COVID,” Bonilla said. “This study speaks to the importance of getting vaccinated if not already and then [getting] subsequent boosters as indicated.”

In addition to the PACS Clinic, Stanford Medicine announced on Nov. 22 that its researchers are embarking on a four-year long-COVID study sponsored by the National Institutes of Health (NIH).

As a part of the NIH’s Researching COVID to Enhance Recovery Initiative, the Stanford team — which includes Stanford Medicine professors Upinder Singh, P.J. Utz, Catherine Blish and Yvonne Maldonado — is expected to receive nearly $15 million in funding for the study of prevention and treatment of long-COVID. Stanford Medicine will also enroll 900 COVID-19 survivors and long-COVID patients in the study to monitor over four years. 

Singh, one of the study’s principal investigators, said that there has not yet been a definitive study that tries to define the epidemiology as well as the pathophysiology of long-COVID.

For the researchers, they hope that their funding and patient pool will assist them in answering essential questions on long-COVID. 

“How often does it happen? In whom does it happen? Can we predict who will get long-COVID? Can we treat or prevent it? These are the questions that this study aims to answer,” Singh said. She said she hopes to find answers as a team with researchers across the country. 

“Stanford Medicine will be part of a large national effort to understand long-COVID. Our contributions will be on the recruitment of individuals who have had COVID, as well as appropriate controls and to help answer questions,” Singh added. “We have much to learn.”

Enkhjin Munkhbayar is a beat reporter in the News section covering international students. Contact Enkhjin at news ‘at’

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