Long COVID and Multisystem Inflammatory Syndrome in Children (MIS-C)


“Long COVID” or Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) refers to the prolonged symptoms or new or returning symptoms that people may develop after recovery from initial SARS-CoV-2 infection. Large numbers of people have reported symptoms such as fatigue, shortness of breath, “brain fog,” sleep disorders, gastrointestinal issues, chronic cough, anxiety, and depression, which can persist for months and range from mild to incapacitating.

NIAID is conducting and supporting research, such as natural history studies, to understand what factors (e.g. age, sex, existing co-morbidities, and host genetic factors) may impact the development of post-acute symptoms, as well as the incidence and prevalence of long COVID. NIAID is also supporting research to understand the immune and inflammatory responses during acute disease and how those may be connected to long-term sequelae. A better understanding of long COVID is essential to identifying and evaluating interventions to prevent and treat these long-term symptoms. NIAID will support the evaluation of promising therapeutic and prevention strategies.

NIH RECOVER Initiative

NIAID hosted a virtual workshop on long COVID in December 2020 to review existing data on long COVID and to identify knowledge gaps. In February 2021, NIH announced a major new initiative to learn more about how SARS-CoV-2 may lead to such widespread and lasting symptoms, and to develop ways to treat or prevent these conditions. The NIH REsearching COVID to Enhance Recovery (RECOVER) Initiative will enable studies that advance understanding of long COVID by enrolling new cohorts of COVID-19 survivors and also by leveraging existing long-running large cohort studies. Read more about the RECOVER Initiative.

MIS-C and Long COVID in Children

The Centers for Disease Control and Prevention define multisystem inflammatory syndrome in children (MIS-C) as a condition where different body parts can become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs. The cause of MIS-C is not yet known, but many children who develop MIS-C previously had COVID-19.

CARING for Children with COVID

NIAID, the National Heart, Lung, and Blood Institute (NHLBI) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) have launched the Collaboration to Assess Risk and Identify Long-term Outcomes for Children with COVID (CARING for Children with COVID), which is developing and funding studies to investigate why some children are at greater risk for SARS-CoV-2 infection than others, why symptoms vary among children who are infected, and how to identify children at risk for severe illness, including MIS-C, from SARS-CoV-2 infection. Read more about CARING for Children with COVID.


NIAID is evaluating the short- and long-term health outcomes of SARS-CoV-2 infection in children, including MIS-C, and characterizing the immunologic pathways associated with different disease presentations and outcomes. Read more about the Pediatric Research Immune Network on SARS-CoV-2 and MIS-C (PRISM) study.

NIH Clinical Center and Children’s National Hospital Study

As part of the RECOVER Initiative, NIAID and Children’s National Hospital in Washington, D.C., are conducting a long-term study on the impacts of COVID-19 on children. The study is expected to yield a detailed picture of COVID-19’s effects on the overall health of children, their development and immune responses to infection, and their overall quality of life in the years following infection. Read more about the study.

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