Discover what the latest science from the RECOVER Initiative means for our ability to understand, diagnose, prevent, and treat Long COVID.
This page contains descriptions of findings from RECOVER research studies. These descriptions use plain language and a format that is easy to understand.
If you want to learn more about the scientific discoveries described here, you can also browse and search the complete list of RECOVER Publications.
In this RECOVER study, researchers wanted to find out which health conditions were common in people with long-term effects of COVID-19, known as Long COVID. They looked at the medical records of over 14 million patients who had and did not have COVID using a method called topic modeling. Topic modeling is a method to find patterns in groups of documents. Researchers used topic modeling to look at lists of health problems that millions of patients faced over time, including before and after they had COVID. This allowed them to find the conditions that were more common in people with Long COVID. Researchers found that health problems related to the lungs, heart, brain, and immune system were more common in people with Long COVID compared to those who didn’t have Long COVID or had not had COVID. Common problems included chronic fatigue (feeling tired all the time), headaches, anxiety, and heart issues. They also found that some problems were more common in people of a certain age or sex (whether they are male or female). The study shows that Long COVID can affect many parts of the body and highlights how health problems can differ between groups. It also shows that age and sex can affect the chance of getting certain health conditions after COVID.
Metformin is a drug that many doctors prescribe as treatment for type 2 diabetes mellitus (T2DM). Studies in the past have found that taking metformin before and during a COVID-19 infection helps lower the chances of getting very sick with COVID. These studies also found that taking metformin can lower the chance of a person being sick many months after getting COVID, which is called Long COVID. In this study, RECOVER researchers were interested in understanding if people with diabetes who were on different medications got Long COVID or died. They looked at electronic health records (EHRs), or computer-based versions of patient health records, for 88,342 adults with T2DM. The study looked at 2 groups. The first group used metformin to control their diabetes, while the second group used other medications to control their diabetes. The researchers found that the chances of getting Long COVID or dying were a little bit lower in the group that took metformin compared to the group taking other medications. Since being on metformin may help only a little bit with Long COVID for adults with T2DM, people taking diabetes medications do not need to change their treatment plans unless told by their doctor.
Many research centers have general formal guidelines about whether and how employees can participate in research studies. However, these guidelines don’t always discuss the risks and benefits of researchers, staff, and community partners enrolling in studies they are involved in, which can create ethical questions. It is very important to consider these ethical questions for studies that aim to enroll large numbers of diverse participants.
All authors of this article are part of the Researching COVID to Enhance Recovery (RECOVER) Initiative, a large study enrolling participants at multiple locations across the country. They used what they learned from RECOVER to address what’s currently missing from existing policy and ethics papers by creating a set of guidelines for how research studies can enroll researchers, staff, and community partners. The authors conclude that people should not be excluded from participating in their own research studies if certain requirements are met and there are rules to ensure everyone’s safety.
RECOVER researchers know that there is a lot of important information about COVID-19 and Long COVID in electronic health records (EHRs), especially in the notes that doctors write during care. The researchers used a computer tool called Natural Language Processing (NLP) to find signs and symptoms of different conditions. However, NLP doesn’t always work well, especially with new health problems like COVID or Long COVID, which are always changing. To improve this, researchers created a new NLP system that could collect detailed information about Long COVID signs and symptoms from EHRs. After testing the system at other medical sites, they found it worked well across different locations. The study showed that the new NLP system could successfully find the information they were looking for about COVID and Long COVID in EHRs. The NLP is now available to other researchers and is being used to collect information that can support additional studies on COVID and 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. 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 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. This is because researchers could not tell if COVID caused the differences in the blood, or if they were there before people got sick.
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. 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 COVID, such as obesity, depression, or anxiety. Future research will focus on whether having COVID while pregnant changes the chance of developing Long COVID. Researchers will compare this to people who got COVID 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 a COVID infection. 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
This RECOVER study looks at a medicine called nirmatrelvir/ritonavir, which is used to treat COVID-19 in teens and adults who are more likely to be hospitalized from the infection. Researchers wanted to understand why doctors might give this medicine to teens ages 12 to 17. They reviewed electronic health records (EHRs) from January 2022 to August 2023 to find which teens got this medicine after testing positive for COVID. Out of almost 21,000 teens with COVID-19, only 408 got the medicine within 5 days of diagnosis. The study found that teens with long-term health problems were 2.5 times more likely to get the medicine. Those with comorbidities (more than 1 ongoing health problem) were more likely to receive it. But most teens with 1 or more health problems did not receive this medication. This could be a reason why many teens with COVID-19 need to be hospitalized. The study also found that Hispanic or Latino kids were less likely to get the medicine compared to non-Hispanic, white kids. This study shows that kids with chronic health issues are more likely to get nirmatrelvir/ritonavir, but not many kids are getting this medicine overall.
This RECOVER study looks at how often people get COVID-19 more than once and if they develop Long COVID afterward. The study also looks at whether a repeat COVID-19 infection, or reinfection, is worse than the first one. RECOVER researchers identified a reinfection when a person had a positive COVID-19 test at least 60 days after their first infection. They studied the health records of over 3 million patients in different ways to understand COVID-19 reinfections. By studying a large number of patients, the researchers were able to learn key details about COVID-19 reinfections. They found that about 6.9% of people got COVID-19 more than once. Most reinfections happened when the Omicron variant was spreading. Researchers found that Long COVID was more common in people who had COVID-19 for the first time compared to those who were reinfected. This finding suggests that protecting yourself from getting COVID-19 is the best way to prevent Long COVID. People who had a moderate or severe case of COVID-19 the first time were also more likely to get very sick again when they were reinfected. These people were often older and at higher risk of death.
