Research Summaries

This RECOVER study found that adults who had COVID-19 were more likely to develop a condition called myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) compared to those who didn’t have COVID-19. ME/CFS can be very severe and similar to many forms of Long COVID. Even small amounts of effort can lead to days or weeks of physical and mental exhaustion in people with ME/CFS. Researchers studied about 13,000 RECOVER participants and found that 4.5% of people who had COVID-19 in the study later developed ME/CFS, while only 0.6% of those who didn't have COVID-19 got ME/CFS. These findings highlight the need for healthcare professionals to be aware that ME/CFS can develop after having COVID-19.

This RECOVER report looked at how using electronic health records (EHRs) to study Long COVID can be both helpful and challenging. EHRs are digital records with a patient’s health information. One good thing about using EHRs is that researchers can use computer programs to find people who might have Long COVID based on their symptoms. This can help researchers figure out what might increase the risk of getting Long COVID, like age and other health problems. EHRs also provide quick access to health records from many patients, which speeds up Long COVID research. A main problem with studying EHRs is that the information in them is not always complete or consistent because different medical providers enter it in different ways. This makes it harder for researchers to find patterns or other details they need to better understand Long COVID. Even with these challenges, the researchers explain that looking at EHRs can still help us better understand Long COVID and improve the lives of people with Long COVID.

This RECOVER study looked at whether children and teens who had COVID-19 were more likely to have stomach problems later. To do this, researchers compared electronic health record (EHR) data from over 1.5 million US children and teens who had COVID-19 with those who didn’t. The study found that kids who had COVID-19 were 25% more likely to have stomach issues, like belly pain, even after recovering from COVID-19. Specifically, 8.64% of kids who had COVID-19 experienced new stomach problems within a few months of having COVID-19 while only 6.85% of kids who didn’t have COVID-19 had stomach problems. This was true not only a few months after getting COVID-19 but also up to 2 years later. Doctors should be aware that kids who had COVID-19 might have more stomach problems. Knowing this can help doctors check for symptoms early and provide the right care.

In this RECOVER study, researchers aimed to improve a large national database on COVID-19 patients from many hospitals to better answer research questions about Long COVID. They noticed that the current database was missing the details needed to study Long COVID properly. To fix this, researchers created clear, step-by-step instructions to help hospitals add specific details from patients’ electronic health records (EHRs) to data they submitted to RECOVER. These extra details included notes on patient visits to Long COVID clinics, hospital stays, living situations, jobs, and if they needed extra oxygen while in the hospital. By June 2024, 29 hospitals had added this more complete information to the data they submitted to RECOVER. Having the hospitals submit data this way made it easier for researchers to compare patient information from different places. This study shows that using clear and standard ways to collect data are important for big research studies. It also shows that researchers sometimes need more details to study difficult research questions, like those about the long-term effects of COVID.

This RECOVER study looked at whether some children were more likely to have long-term breathing or brain/nerve problems after having COVID-19. Researchers studied the electronic health records (EHRs) of 771,725 pediatric patients under the age of 21 across the US. They found that children under 5 years of age and Hispanic White children had a higher chance of having breathing problems linked to Long COVID. This was also true if they lived in low-income areas or had other breathing problems before getting COVID-19. Children ages 12–17 years old and non-Hispanic White children were more likely to have brain and nerve problems related to Long COVID, especially if they already had other problems related to the brain and nerves. These findings show that race and ethnicity may affect how children experience Long COVID. Factors like where children live and how easy it is for them to get healthcare could play a role in these differences. This research shows why it’s important to understand these factors, so all children can get the care they need after having COVID-19.

Scientists updated a prior RECOVER study to explore Long COVID symptoms reported by participants in the RECOVER-Adult Observational Cohort Study. They compared symptoms in people who had COVID-19 to those who did not have COVID-19 to find the symptoms that were most different. The updated study included 13,647 participants, compared to 9,764 in the original, and added 8 new symptoms based on patient and community feedback. Symptoms that were most different between people with and without COVID-19 include post-exertional malaise, fatigue, brain fog, dizziness, palpitations, smell or taste change, thirst, chronic cough, chest pain, shortness of breath, and sleep apnea. In addition, this research update classifies Long COVID symptoms into 5 groups of symptoms called clusters. The previous study focused on 4 clusters. This study update is important because it highlights the wide range of symptoms experienced by people with Long COVID. Understanding these symptoms will help researchers study Long COVID and look for treatments.

This RECOVER study focused on what causes Long COVID and why it affects people in different ways. Researchers created an "omics" task force made up of doctors, scientists, and data experts. For 14 months, they worked together to figure out the best way to study Long COVID. They recommended using "multi-omics," which means studying many layers of health information at the same time, like genes, proteins, and chemicals that show how the body is working. To do this, RECOVER researchers collected blood, urine, and saliva samples from more than 34,000 people including adults, pregnant adults, and children, at least twice since joining the study. Looking at all these layers together gives a clearer picture than studying them one by one. It also avoids differences between laboratories and makes it easier to find patterns that could tell us more about Long COVID. The research and recommendations are important because they can help researchers find out what causes Long COVID, predict who might get it, and find treatments. The data collected in this study will also be shared with other researchers so they can continue to learn more.

This RECOVER study looked at how a child’s race or ethnicity might affect their chances of developing long-term health problems after getting COVID-19. Researchers studied data from 225,723 children and teens across 13 US hospitals and clinics from March 2020 to October 2022. They compared children who were diagnosed with COVID-19 or had a positive COVID-19 test to those who never tested positive. The study found that children with COVID-19 were more likely to develop many health problems weeks or months after getting COVID-19 than those who never had it. These problems included trouble breathing, feeling very tired (fatigue), and mental health problems.

Researchers also found that the chance of having these problems was different depending on a child's race or ethnicity. For example, Hispanic children with severe COVID-19 were more likely to have hair loss after getting sick than Non-Hispanic White children with severe cases. Non-Hispanic Black children with less severe COVID-19 were more likely to experience cognitive symptoms (related to thinking, memory, or concentration) than Non-Hispanic White children with less severe COVID-19. In children with less severe COVID-19, Asian American/Pacific Islander children were more likely to have more fever, chills, and respiratory symptoms (related to breathing) than Non-Hispanic White children. This study shows that long-term health problems in children and teens after COVID-19 may be different between racial and ethnic groups. This can help doctors better understand and treat Long COVID in people who are more likely to get it.

A RECOVER study looked at whether a person’s sex at birth affects their risk of developing Long COVID. To do this, researchers studied a large group of people enrolled in the RECOVER adult cohort. They found that females were more likely to have Long COVID symptoms than males. Among females, the risk of getting Long COVID changed based on age, pregnancy status while having COVID-19, and if they had gone through menopause. Researchers discovered that the risk of getting Long COVID was higher in females ages 40–54 years and females who had not gone through menopause. On the other hand, females who had already gone through menopause were not at a higher risk compared to males. More research is needed to understand why differences in sex at birth may put someone at higher risk of experiencing the long-term effects of COVID-19. Knowing this and understanding which hormones play a role in Long COVID risk could help researchers develop treatments and ways to prevent Long COVID.