Research Summaries

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 getting COVID-19 multiple times, also called a reinfection, is worse than the first time getting COVID-19. RECOVER researchers identified a reinfection when a person had a positive COVID-19 test at least 60 days after getting COVID-19 for the first time. 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.

Some people develop new conditions or symptoms after having COVID-19, called Long COVID. This can lead to ongoing health problems. Researchers still don’t fully understand why some people get Long COVID while others do not. In this RECOVER study, researchers wanted to learn what increases someone’s risk of developing Long COVID after getting COVID-19. Researchers studied the electronic health records of 2.1 million people from New York and Florida who either had or had not had COVID-19 between March 2020 and November 2021. Using this data, they created a new computational model (a computer program that imitates how something works in real life) to help identify the things that Long COVID patients had in common. The researchers looked at whether these shared factors increased their risk of developing Long COVID. The model found that the people who were more likely to develop Long COVID if they had severe COVID-19 the first time they got the virus, were underweight, or had other health problems, like cancer or liver disease. The results also show that computational models can help identify people who have a higher chance of developing different symptoms and types of Long COVID. This information is important because it can be used to help researchers find new ways to prevent, diagnose, and treat Long COVID.

Little is known about Long COVID in pregnant women. This study looked at whether getting COVID-19 while pregnant might increase the chances of getting Long COVID. Researchers from the RECOVER Patient-Centered Clinical Research Network (PCORnet) checked health records from 19 health systems across the US. They studied women ages 18–49 years old who had a test showing that they had COVID-19 between March 2020 and February 2022, and looked at 83,915 women who were not pregnant and 5,397 who were. Women who got COVID-19 while pregnant were less likely to get Long COVID than those who weren’t pregnant. Pregnant women with COVID-19 were more likely to develop certain conditions related to Long COVID, like an abnormal heartbeat. But they had a lower risk of getting other conditions, like malaise (feeling unwell). Overall, pregnant women with COVID-19 had a lower chance of getting Long COVID in the 30 to 180 days after they first got sick.

This RECOVER literature review paper discusses what researchers know so far about Long COVID and how Long COVID studies can be improved. The paper’s authors reviewed findings from different types of Long COVID studies, including electronic health record (EHR) studies, surveys of large groups of people, and laboratory studies involving animals (including mice). The authors found that Long COVID is difficult to study because results do not always agree across publications. Some study findings suggest that parts of the SARS-CoV-2 virus that causes COVID-19 may stay in the body for months and may affect how the body works. However, more research is needed to know for sure. The authors highlight the need for doctors and researchers to work together to better define Long COVID, learn what causes it, and improve clinical trials that test possible treatments. This literature review is important because it can help guide future Long COVID research, which could lead to clearer answers and better treatments for patients.

The virus that causes COVID-19 can change over time, creating new virus types called variants. This study explored if problems related to Long COVID were different in people who got different variants of COVID-19. Researchers looked at medical records from 2 databases in New York and Florida. They compared people who had the original type of COVID-19 with those who had a variant called Delta, which was one of the main variants in 2021. The researchers found that some Long COVID conditions were more common in the people who had Delta. For example, some people who got the Delta variant developed clots in the blood vessels in their lungs. People who had Delta were also more likely to have stomach symptoms than people who got the original type of COVID-19. Based on these findings, the researchers concluded that Long COVID symptoms can be different depending on which variant of COVID-19 someone had.

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.

The researchers and study team running the RECOVER-NEURO clinical trial published a paper detailing the study’s design. RECOVER-NEURO is looking at 3 possible treatments for cognitive dysfunction, or brain fog, symptoms related to Long COVID. The possible treatments, also called study interventions, are BrainHQ (an interactive online brain training program), PASC-Cognitive Recovery (an online goal management training program), and transcranial direct current stimulation (a safe, noninvasive form of brain stimulation). The research team is using a variety of assessments, including brain function tests and participant surveys, to determine if these study interventions reduce brain fog symptoms and help people function better.

People with brain fog may have trouble thinking clearly, remembering things, or focusing on tasks, which can severely affect their daily functioning and quality of life. Results from this study will help the Long COVID community learn if BrainHQ, PASC-Cognitive Recovery, and transcranial direct current stimulation can be used to treat cognitive dysfunction symptoms related to Long COVID.

Long COVID may occur in people recovering from a COVID-19 infection and often includes symptoms related to the heart and lungs, which together are called the cardiopulmonary system. These symptoms, which include fatigue, shortness of breath, chest pain, cough, and reduced ability to do physical activity, can cause significant disability. This paper explores current knowledge about what causes Long COVID and how it affects the heart and lungs, in both adults and children. The authors also discuss how participants in the Researching COVID to Enhance RECOVERY (RECOVER) Initiative will help answer questions about the impact of Long COVID on the cardiopulmonary system. Understanding these causes and effects may help researchers discover new therapies for Long COVID symptoms. 

Research shows that the COVID-19 vaccine lowers the chance of children getting sick from COVID-19. But it is not clear whether the COVID-19 vaccine protects against Long COVID. RECOVER researchers did a study to look at how well vaccines work in protecting children, ages 5–17, against Long COVID. They studied data from a group of more than 1 million children. The vaccine was 42% effective in lowering the chance of getting Long COVID in kids ages 5–11 and 50% effective for kids ages 12–17. The vaccine works best against Long COVID within the first 6 months of getting it. After 6 months, it does not work as well, so getting the vaccine every year is important to prevent Long COVID. These results show that the COVID-19 vaccine can help children 5 years and older to keep from getting very sick. While this study helps scientists understand how vaccines can protect against COVID-19, they still need to do more research to understand how they protect against Long COVID.