RECOVER Research Update: September 2026

Clinical Trials

Patient-centered study tools help measure the effectiveness of possible Long COVID treatments

• Researchers working on RECOVER Clinical Trials (RECOVER-CT) found that study tools called patient-reported outcome measures (PROMs) did a good job of reflecting the experiences of people with Long COVID and were easy for participants to use.
• In this study, 30 English-speaking adults with Long COVID reviewed 4 PROMs. Each PROM focused on different symptoms relevant to specific RECOVER clinical trials.
• Most reviewers said the PROMs were easy to understand and reflected their experiences. However, reviewers also suggested several changes to the PROMs—including simpler instructions, clearer wording, and shorter questionnaires—that could help make them easier to understand and use.
• These findings show that, with some improvements, PROMs can be useful tools for measuring the effectiveness of possible Long COVID treatments.

Observational Cohort Studies

People with kidney disease may experience worse COVID-19 outcomes, including Long COVID, than people without kidney disease

• This study found that people with pre-existing chronic kidney disease (CKD) may be more likely to experience severe COVID-19 than people without CKD. It also found that COVID-19 vaccines may trigger a weaker immune response in people with more advanced CKD.
• Among the 26,039 participants in this study, most (about 82%) belonged to a group with low CKD risk. Of those 26,039 participants, 4,791 (18%) got COVID-19. Almost 12% of participants with COVID-19 met criteria for likely Long COVID as defined by RECOVER’s Long COVID Research Index (LCRI). This link was strongest among study participants with the most advanced CKD.
• These findings may help researchers better understand which pre-existing health conditions put some people at greater risk of experiencing severe COVID-19 and developing Long COVID. These findings also support the need for continued research in 2 areas:
  • How underlying kidney disease influences recovery from COVID-19.
  • How to improve COVID-19 outcomes for people with CKD.

Long COVID’s impact on a person’s physical fitness can last for years

• Many Long COVID symptoms can affect the heart and lungs, or cardiopulmonary system. Researchers wanted to learn more about the overall long-term health effects of these symptoms.
• Researchers analyzed data shared by 1,475 adults participating in RECOVER’s Digital Health Program (DHP).
• Almost 1 in 3 adults participating in the DHP had a high burden of Long COVID symptoms. These people also had higher resting heart rates, lower heart rate variability, fewer daily steps, lower activity levels, and lower indicators of physical fitness than DHP participants with a low Long COVID symptom burden.
• These findings suggest that Long COVID can limit some people’s physical activity for several years. Researchers recommend that future studies focus on understanding whether Long COVID increases a person’s risk of developing cardiopulmonary disease.

Some health conditions and medications may influence how the body reacts to SARS-CoV-2

• Researchers compared people with pre-existing health conditions called systemic autoimmune rheumatic diseases (SARDs) who’d had COVID-19 to people without SARDs who’d had COVID-19. They examined whether people with SARDs experience longer viral persistence, which is when pieces of a virus—like SARS-CoV-2—remain in the body for weeks or months after someone has recovered from their acute (initial) illness.
• SARDs are chronic (long-lasting) health conditions, like lupus and rheumatoid arthritis, in which an overactive immune system begins attacking the body itself. Researchers also wanted to know if SARDs medications may be a factor that contributes to viral persistence. These medicines suppress (calm) the immune system, which means it may be less effective at responding to viruses.
• Researchers found evidence of viral persistence in the blood of almost 37% of study participants with SARDs. About 19% of study participants without SARDs had evidence of viral persistence in their blood samples.
• Researchers then looked at whether people with SARDs who had evidence of viral persistence in their blood were more likely to have Long COVID symptoms. In this part of the study, they did not find a significant link. However, this part of the study only included 37 people, so it may have been limited in its findings.
• Better understanding when, how, and why viral persistence occurs could help researchers develop more targeted approaches to preventing and treating Long COVID.

EHR Studies

Advanced computer programs can reliably identify people with likely Long COVID based on their health data

• Researchers found that an advanced computer program called a computable phenotype algorithm could reliably identify people who probably have Long COVID based on their medical records.
• This study included 1,501 adults participating in RECOVER’s adult observational study. Researchers only included those people who had EHR data linked to symptoms they reported when responding to health surveys.
• The algorithm showed good accuracy. In most cases, the algorithm correctly distinguished people with highly symptomatic Long COVID, as defined by RECOVER’s LCRI, from people without it.
• Researchers found that simply searching medical records for the official Long COVID diagnostic code (U09.9) performed poorly on its own. This suggests that Long COVID is underdiagnosed or underdocumented in routine care.
• These findings could help use available information in health records to address a major challenge in Long COVID research: quickly and accurately identifying people who are good candidates to participate in Long COVID studies, including clinical trials.

Long COVID can impact children’s mental and emotional health

• This study found that young people with Long COVID were more likely to experience difficulties participating in everyday activities, like going to school or playing with friends, than children who had COVID-19 but did not develop Long COVID.
• First, researchers used an algorithm to find symptom, diagnosis, and treatment patterns in EHR data provided by 21 children’s hospitals across the United States. Specifically, researchers asked clinicians whether they agreed with the computable phenotype’s determination that an individual should be diagnosed as having Long COVID.
• Young people with likely Long COVID were more likely to experience one or more functional impairments when compared with the young people the clinicians decided should not be diagnosed with Long COVID.
• These findings highlight that Long COVID can affect more than a young person’s physical health. For this reason, the authors of this publication urge that Long COVID care for young people include a focus on growth, learning, and emotional well-being.

Steroid treatment is not linked to a lower risk of Long COVID in children

• Researchers wanted to know if steroids—medicines that can reduce inflammation (swelling) and calm overactive immune systems—could help prevent Long COVID in children and adolescents (teens up to age 19).
• Using more than 850,000 EHRs, researchers compared children who received a steroid treatment within 12 days of getting COVID-19 with children who did not. Researchers also looked to see which children developed Long COVID within 6 months.
• Researchers found that, with one exception, children with COVID-19 who received steroid treatments were neither more nor less likely to develop Long COVID than children who did not receive steroids.
• These findings could inform future research to understand which treatments may help prevent Long COVID in children.

SSRI/SNRI use is not linked to a lower risk of Long COVID in children, but may affect the Long COVID symptoms children experience

• Researchers wanted to know whether 2 drugs—selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs)—might help prevent Long COVID in young people.
• Many young people with neuropsychiatric conditions (mental and emotional health issues), such as anxiety and depression, take SSRIs or SNRIs. Researchers wanted to study SSRIs or SNRIs because they can affect both the immune system and the autonomic nervous system, which is the body system that controls autonomic functions (automatic activities like breathing and heartbeat).
• Researchers examined EHR data collected from 37 health systems across the United States. By analyzing this data, researchers identified almost 111,000 children (ages 5–11), adolescents (ages 12–15), and older adolescents (ages 16–20) who had been diagnosed with an existing neuropsychiatric condition before they got COVID.
• Researchers found that young people taking an SSRI or SNRI were neither more nor less likely to be diagnosed with Long COVID than young people not taking an SSRI or SNRI.
• Researchers looked at which Long COVID–related symptoms were most common in these 2 groups of young people (those who were taking an SSRI or SNRI and those who were not).
• Young people taking an SSRI or SNRI were more likely to experience Long COVID symptoms like cognitive dysfunction (thinking and memory problems), fatigue (extreme tiredness), and postural orthostatic tachycardia syndrome (POTS). POTS is an autonomic disorder that can cause symptoms like dizziness, rapid heartbeat, and being unable to stand for long periods.
• Young people who were not taking an SSRI or SNRI were more likely to experience Long COVID symptoms such as fever, chills, and breathing problems.
• These findings suggest that healthcare providers should tailor their COVID and Long COVID care for young people diagnosed with neuropsychiatric conditions.

Pathobiology Studies

Viral variants and a child’s age, sex, race, and ethnicity can influence their COVID-19 outcomes

• Researchers found that 2 factors may work together to influence how severe (bad) a young person’s COVID-19 symptoms can be:
  • The version, or variant, of SARS-CoV-2 virus that causes a young person’s COVID-19.
  • A young person’s age, sex, race, and ethnicity (demographic characteristics).
• Researchers classified COVID-19 cases as mild, moderate, or severe based on whether a young person’s symptoms were severe enough to require a hospital stay or respiratory support (help from a breathing machine). Researchers then examined how COVID-19 severity was related to viral variants, age, race and ethnicity, and other demographic factors.
• Compared with pre-Omicron variants, Omicron variants were associated with a higher risk of a young person developing either moderate or severe COVID-19 symptoms.
• Researchers also found relationships between COVID-19 severity and a young person’s age, sex, and race.
• This study reveals patterns that could help explain why some young people may be at higher risk of experiencing severe COVID-19 or developing Long COVID.

Different immune system responses may lead to different COVID-19 outcomes in children

• Researchers found that a child’s COVID-19 symptoms may depend, in part, on how their immune system responds to SARS-CoV-2.
• Researchers wanted to understand whether children who did not get very sick because of COVID-19, children who got very sick because of COVID-19, and children who developed multisystem inflammatory syndrome in children (MIS-C) had different antibodies in their blood.
• Researchers measured levels of different antibodies in children’s blood samples. Specifically, they measured levels of antiviral antibodies, which target SARS-CoV-2, and autoantibodies, which mistakenly target a person’s own tissues or proteins instead of viruses or bacteria.
• Researchers found high levels of antiviral antibodies in the blood of children who’d had COVID compared to those who hadn’t had COVID. However, researchers found that these levels were the same regardless of how sick a child became with COVID or whether they developed MIS-C.
• Additionally, levels of some autoantibodies were higher in children who became very sick because of COVID-19. This includes autoantibodies that can cause inflammation and autoantibodies that can target the thyroid gland.
• By comparison, children whose COVID-19 symptoms were milder had higher levels of other autoantibodies in their blood.
• These findings suggest that different patterns of autoantibodies may be partially responsible for how COVID-19 affects a child. Better understanding these autoantibody patterns could help researchers better understand the long-term effects COVID-19 can have on the immune system.

Long COVID symptoms affecting the brain and nervous system could be caused by the immune system targeting the body’s own cells

• Researchers found that autoantibodies could be one cause of Long COVID symptoms affecting the brain and nervous system. These symptoms, also called neurological symptoms, include headaches, fatigue, and having difficulty thinking clearly, concentrating, or remembering things.
• Researchers found that adults with Long COVID had increased levels of a broad range of autoantibodies (immune cells that can damage the body) in their blood. Researchers also found that certain autoantibodies were associated with specific Long COVID symptoms.
• For example, an autoantibody called immunoglobulin G (IgG) can react to an area of the brain that controls alertness and the body’s response to stress. IgG was more likely to react to this area of the brain in adults who had lost their senses of taste and smell due to Long COVID.
• Next, researchers observed how mice behaved for up to 5 days after being injected with human autoantibodies associated with specific Long COVID symptoms.
• In several cases, these mice showed signs of developing the specific Long COVID symptoms associated with the autoantibodies they received.
• For example, mice who received autoantibodies from adults experiencing any neurological symptoms of Long COVID showed signs of fatigue after spending time on a treadmill.
• These findings could inform the development of targeted treatments for different types of Long COVID.