Research

Several RECOVER studies report on the symptoms of Long COVID. View studies [1], [2], [3], [4], [5], [6]. RECOVER research shows there are symptoms that cluster and present together. View studies [1], [2], [3]. In one study, researchers found six distinct symptom clusters. The clusters involve different body systems at the same time, including: the lung; brain and nervous system; heart and blood vessels. Some clusters include pain, and some are accompanied by abnormal laboratory findings. View the study. Another study found that four Long COVID symptom clusters (heart and lungs, neurological, gastrointestinal, and coexisting medical conditions) differed depending on the age of patients. In the study, children and teens were more likely to have gastrointestinal and upper respiratory problems (such as stomachache and cough); adults aged 21-45 years were more likely to have neurological problems (such as brain fog and fatigue); and adults aged 66 and older were more likely to have coexisting medical conditions (such as heart problems and diabetes). View the study.

RECOVER researchers are also examining how PASC diagnoses, underlying health conditions, and prescription medications might differ geographically. They compared electronic health records from four states (New York City, Florida, Georgia, and Alabama) and found differences in the number of PASC conditions reported across data sites. Researchers found a wide range of diagnosis and medication categories that suggest differences in PASC diagnoses, conditions, and medications among different populations based on neighborhood socioeconomic status, age, gender, race, and outbreak waves. View the study.

Researchers found ethnic and racial differences in PASC symptoms and conditions in a RECOVER study of adults with COVID-19 in New York City between March 2020 and October 2021. In the 30-180 days after infection, compared to White people hospitalized for COVID-19, Black and Hispanic people hospitalized for COVID-19 had higher rates of certain PASC symptoms such as shortness of breath, chest pain, joint pain, and newly diagnosed diabetes. Results also suggest that people from different racial and ethnic groups may experience different symptoms and conditions of PASC. View the study.

RECOVER researchers are studying large groups of people over a long period of time to gain a deeper understanding of Long COVID, how long its symptoms last, and whether it can have effects later in life. Learn more about RECOVER Longitudinal Observational Cohort Studies.

RECOVER researchers are studying if Long COVID affects other diseases or health problems that people may have. RECOVER researchers compared electronic health records (EHR) to examine the possible link between SARS CoV-2 infection and new diagnoses of type 2 diabetes. Patients who had at least 1 visit 6 months before their SARS CoV-2 infection and 6 months of EHR data post-infection were included in the analysis. Researchers found the number of new diabetes diagnoses to be lower in the months after SARS-CoV-2 infection than in the months before. New diabetes cases in the 6 months after infection were 83% lower than in the 6 months before infection. View the study.

RECOVER studies are examining risk factors for developing Long COVID.

RECOVER researchers have found that SARS-CoV-2 infection increases the risk of developing PASC and Long COVID. View studies [1], [2], [3]. People who tested positive for SARS-CoV-2 between March and December 2020 and were hospitalized or received mechanical ventilation during their illness had a higher prevalence of multiple symptoms at 1 to 5 months after testing positive compared to those who tested negative. The symptoms included: shortness of breath, heart rate abnormalities, fatigue, brain fog, sleep disorder, type 2 diabetes, and muscle weakness. View the study. In another study, researchers found that 23% of people with SARS-CoV-2 infection developed PASC, while only 3.7% of people without a reported positive test developed symptoms consistent with PASC. View the study.

A large RECOVER study looked at risk factors associated with specific PASC conditions. Researchers found that the risk of PASC increases with hospitalization for acute infection and similarly with reinfections. View the study. Another study found that 39% of people hospitalized with acute COVID-19 developed PASC, compared to 22% of people not hospitalized for acute COVID-19. Among people infected with the Omicron variant, those that had reinfections were more likely to develop PASC (21%) compared to those with one infection (16%). View the study.

RECOVER research using electronic health records (EHR) suggests that obstructive sleep apnea may increase the risk for developing Long COVID after infection. Among people who had COVID-19, adults with obstructive sleep apnea were more likely to experience long-term symptoms suggestive of Long COVID than those without the sleep disorder. The analysis of EHR found that adults with sleep apnea may have up to a 75% higher risk of developing Long COVID after infection. View the study.

RECOVER researchers found that certain environmental factors related to where people live, like air quality, access to food, green spaces, neighborhood characteristics, and social factors, may increase the risk of having Long COVID symptoms. View the study.

RECOVER researchers are exploring whether variants of the SARS-CoV-2 virus and COVID-19 vaccines make a difference for developing Long COVID.

In a study following more than 9,000 people over time, RECOVER researchers found that PASC was more common and associated with more severe manifestations for adults infected before the Omicron variant emerged. View the study. Regardless of the variant, the rates of PASC among those fully vaccinated were lower than those who were unvaccinated. Researchers found the same pattern when they compared vaccinated and unvaccinated adults at three different points in time - in adults with post-acute COVID, pre-Omicron (31% vs. 37%), with acute Omicron infection (9.7 vs. 17%), and post-acute Omicron (16% vs. 22%). Similarly, in a large observational study, RECOVER researchers found that vaccination was consistently associated with lower rates of Long COVID, before and after Omicron emerged. View the study.

RECOVER researchers reviewed the electronic medical records of more than 15 million people (age 5 and older) to compare the risk of rare heart problems in people who had a SARS-CoV-2 infection with people vaccinated for COVID-19. They found that the risk of having a rare heart problem after having COVID is much higher than the risk after vaccination. The risk of rare heart problems after COVID-19 vaccination with an mRNA vaccine (Pfizer or Moderna) were very, very low, supporting the continued use of vaccination to prevent COVID-19. View the study.

In addition to the observational cohort studies that re-examine participants over time, RECOVER researchers are conducting more than 40 different pathobiology studies focusing on COVID-19's effects on different body tissues and organs.

At this time, the only known way to prevent Long COVID is to avoid getting COVID-19. The observational cohort studies and the RECOVER Pathobiology Research Program are investigating potential mechanisms for how some people may be protected from Long COVID or some of its symptoms.

RECOVER researchers are making progress toward understanding why some people develop Long COVID and how these long-term symptoms affect one’s health. Based on what the researchers have learned so far, RECOVER has launched clinical trials to test different interventions for Long COVID. Two RECOVER clinical trials have launched, with three more planned: RECOVER NEURO and RECOVER VITAL. RECOVER NEURO focuses on treatments for cognitive symptoms associated with Long COVID [learn more]. RECOVER VITAL (viral persistence and reactivation, and immune dysregulation) focuses on treating viral persistence—which is when the SARS-CoV-2 virus stays in the body and damages organs or the immune system. Viral persistence or reactivation are possible explanations for what causes Long COVID symptoms. This trial focuses on treatments to stop the virus from causing continued damage and to resolve symptoms caused by the virus [learn more]. Learn more about RECOVER Clinical Trials.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a type of Long COVID that may develop in children and young adults. In a small study with seven outpatient children diagnosed with MIS-C, outpatient treatment alone was sufficient, and they did not need hospitalization. View the study.