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.

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.

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.

This RECOVER study looked at 25 different blood tests to see if any of the tests could be used to tell if someone might have Long COVID. Long COVID is when someone feels sick for a long time after having COVID-19. Researchers took blood from people who did and did not have COVID-19. They took blood from both groups 6 months after they got infected or after they joined the study. Researchers found small differences between the blood of people in each group. People who had COVID-19 had slightly lower platelet counts (platelets help stop bleeding), a bit more sugar in their blood, and signs of possible kidney problems. But, these differences were very small and might not be very important in finding out if someone has Long COVID. The study found that none of the 25 blood tests could show if someone has Long COVID because the test results were too similar between people with Long COVID and those without it. 

The RECOVER Initiative did a study to see how often pregnant women get Long COVID. The study looked at 1,502 pregnant participants. Participants took surveys about Long COVID symptoms around 10 months after they first got COVID-19. About 9% of them reported having Long COVID symptoms. The most common symptoms participants had were feeling very tired, especially after physical or mental activity, or being tired all the time. Some participants had stomach and gut problems. RECOVER researchers also found that people were more likely to get Long COVID if they needed extra oxygen while sick with COVID; had trouble paying bills; or had other health problems before having COVID-19, such as obesity, depression, or anxiety. Future research will focus on whether having COVID-19 while pregnant changes the chance of developing Long COVID. Researchers will compare this to people who got COVID-19 when they were not pregnant.

This RECOVER study is one of the first of its kind to look at Long COVID symptoms in children across age groups. Researchers for this study also developed a new research tool to help identify children who were most likely to have Long COVID. The study asked about prolonged or long-lasting symptoms in both school-age children (ages 6 to 11 years old) and teenagers (ages 12 to 17 years old) and compared these symptoms between those with and without a history of COVID-19. The symptoms that were most likely to identify school-age children with Long COVID were trouble with memory or focusing, back or neck pain, stomach pain, headache, fears, refusing to go to school, skin rashes, trouble sleeping, nausea or vomiting, and lightheadedness or dizziness. The symptoms that were most likely to identify teenagers with Long COVID included change or loss of smell or taste, bone, muscle or joint pain, back or neck pain, feeling tired all day or after walking, having low energy, trouble with memory or focusing, headache, and lightheadedness or dizziness. These study findings show Long COVID symptoms can affect almost every organ system in the body. It also showed that while many of the symptoms between the two age groups were similar, there were differences. Understanding why these differences occur can help create future Long COVID treatments for children that are age-group specific. Read the Research Q&A

Having COVID-19 can lead to new symptoms or symptoms that do not go away. This condition is called Long COVID. RECOVER researchers are working to answer questions about Long COVID in children. To do this, they are studying over 15,000 children and their caregivers in the US to understand how common Long COVID is in children and their caregivers; how the body changes when someone has Long COVID; what makes some people more likely to develop Long COVID, such as where a person lives and their age, race, and sex; and what happens in the body that might cause Long COVID. This paper is important because it can show other scientists how to do their own research on Long COVID in children.

Having COVID-19 can lead to new symptoms, or symptoms that do not go away. This condition is called Long COVID. RECOVER researchers are working to answer questions about Long COVID in pregnant women. To do this, they are studying 2,300 pregnant women and their babies in the US to understand how often pregnant women get Long COVID; how the body changes when someone has Long COVID; what makes some people more likely to develop Long COVID, such as where a person lives and their age, race, and sex; and what happens in the body that might cause Long COVID. RECOVER researchers are also studying how COVID-19 during pregnancy affects child development. This paper is important because it can show other scientists how to do their own research on Long COVID in pregnant women.

Having COVID-19 can lead to new symptoms or symptoms that do not go away. This condition is called Long COVID. RECOVER researchers are working to answer questions about Long COVID in adults. To do this, they are studying more than 14,700 adults in the US to understand how common Long COVID is in adults; how the body changes when someone has Long COVID; what makes some people more likely to develop Long COVID, such as where a person lives and their age, race, and sex; and what happens in the body that might cause Long COVID. This paper is important because it can show other scientists how to do their own research on Long COVID in adults.