Slow enrollment has led to simmering frustrations over the progress and potential of the NIH's RECOVER Initiative, the research consortium focused on studying post-acute sequelae of SARS-CoV-2, or long COVID, according to researchers and leaders within the initiative.
The was designed to support research on long COVID across the U.S., including among every group of people affected by this poorly understood condition.
More than 40% of American adults have reported a COVID-19 infection, and 19% have reported experiencing symptoms of long COVID, according to collected by the U.S. Census Bureau and reviewed by the CDC. In total, the survey results suggest that nearly 20 million U.S. adults are suffering from these symptoms.
This large-scale impact is one of the reasons behind the RECOVER Initiative's slow start, said Walter Koroshetz, MD, director of the National Institute of Neurological Disorders and Stroke and co-chair of RECOVER's Senior Oversight Committee, noting that the initiative is designed to cast a wide net as it starts to recruit participants for the many arms of the initial observational studies.
"We want to come up with solutions for the medical community. That's the whole purpose," Koroshetz told ֱ. "But if it's quick and easy, then someone else is going to get it quick and easy and that would be fine. RECOVER was set up as if there is no quick, easy solution to this problem. And we know right now that looks like the case."
Koroshetz compared long COVID to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) found in other post-viral infections, like Lyme disease or Epstein Barr virus, which can affect people for decades.
"There's a real chance that this is not going to be easy, and it's going to be more like what we've seen with ME/CFS," he said. "RECOVER is put together to leave no stone unturned, so if we don't figure this out at the end of RECOVER, it's not because we didn't try. It's going to be because it's just too hard a problem."
Slow Start to Enrollment
Overall, enrollment for the adult cohort of the study has been preceding as planned, according to Koroshetz. But the Initiative has run into challenges for specific groups, including the acute infection cohort, the pediatric cohort, and the autopsy cohort.
The acute infection cohort has not enrolled as quickly largely due to a lack of awareness of the program, Koroshetz said, noting that most people with COVID-19 are not seeking treatment, which means their healthcare providers are not even able to recommend that they join the study.
He explained that while this specific cohort has proven to be the most difficult to recruit, it is also one that researchers are eager to observe, since it is important to understand "the differences in the recovery process from the acute stage to either a normal recovery [with] no symptoms compared to a pattern which leaves you with persistent symptoms."
The autopsy cohort has a similar problem in that the awareness of need for participation is low, Koroshetz said. Researchers for this cohort need people and their families to be aware of the study and willing to choose to be enrolled after their death.
The pediatric cohort is struggling to enroll mostly due to delays in paperwork, explained Lawrence Kleinman, MD, MPH, of the department of pediatrics at Rutgers Robert Wood Johnson Medical School in New Jersey.
Kleinman, who leads the pediatric study hub at Rutgers, compared the RECOVER studies to a team trying to build an airplane as it is rolling down the runway.
"It's a complicated study in terms of enrollment. It's a complicated study in terms of assessment. It's a complicated study because we don't have an encompassing definition with any detail about this illness," he said. "It's very hard to study an emerging disease [when] you don't have parameters ... around it when you begin."
Focused on the Future
One cohort that has not seen difficulties with enrollment is the primary adult population, with some research sites more than half full. Sally Hodder, MD, of West Virginia University's Health Sciences Center, said that her research group has enrolled more than 60% of the targeted 914 participants across their sites, which includes locations in Maine, Puerto Rico, Hawaii, and several states in the Midwest and South.
Hodder expects to reach full enrollment in her group by the fall, but admits that her sites are only part of the 17,700-adult study group. She noted that the important thing to remember about RECOVER is that it is a large observational study that is trying to understand how long COVID affects all communities throughout the country.
"I think any study, when you start, it's sort of an exponential curve," Hodder told ֱ. "You start and it builds slowly, and then that enrollment curve becomes much more steep, and in fact, that is exactly what is happening with RECOVER."
The more people are aware of the work they are trying to do with RECOVER, the easier enrollment will become, she said.
Researchers across several RECOVER study sites agreed that the slow enrollment was not unexpected, but they all stressed that they are on the right path to collecting the necessary data to better understand long COVID.
"The RECOVER Initiative is really trying to do an exhaustive study of this condition, to get answers to patients, [and] provide the practitioners with the tools to reduce their suffering," Koroshetz said. "I feel the frustration, but I do feel that this is the best thing to do, so that we're not frustrated 10 years from now. It's the best chance of getting the answers."