Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
UPDATE
The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.

CDC Science behind Long COVID

CDC Science behind Long COVID

How CDC is using science to learn more about Long COVID

Updated Mar. 14, 2024

For the General Public: Long COVID (Post-COVID Conditions)

Long COVID is a real illness and can result in chronic conditions that require comprehensive care. There are resources available.

Long COVID includes a wide range of new, returning, or ongoing health problems people can experience 4 or more weeks after being infected with SARS-CoV-2, the virus that causes COVID-19.

What CDC Is Doing to Learn about Long COVID

CDC is analyzing healthcare data, partnering with clinicians, and working with researchers to learn more about Long COVID in a variety of populations and settings. These partnerships are essential for expanding the base of evidence needed for addressing Long COVID. CDC and its partners are working to:

  • Characterize and assess Long COVID to estimate both the risk of experiencing Long COVID and the numbers of people experiencing these conditions by demographic group.
  • Identify risk factors to better understand how to prevent Long COVID.
  • Identify groups disproportionately affected by Long COVID.
  • Assess the burden (health and financial costs) of Long COVID.
  • Identify successful interventions to prevent and lessen the effect of Long COVID. This research includes:
    • Assessing if COVID-19 vaccinations and treatment reduce the occurrence of Long COVID, and
    • Promoting equity in healthcare access and utilization for people with Long COVID.
  • Disseminate clinical guidance and other education materials for healthcare providers, patients, and the public to improve understanding of Long COVID.
Science at CDC
Scientific articles and manuscripts about COVID-19 and Long COVID

MMWR COVID-19 ReportsCDC Scientific Publications on COVID-19

CDC and partners are collecting and analyzing information about Long COVID and health problems through several public health activities, including:

  • Prospective cohort studies that observe people over time,
  • Sentinel surveillance to collect information from select public health sources on cases of Long COVID,
  • Medical chart abstraction to understand the health and medical care of patients with Long COVID,
  • Analyses of electronic healthcare data and large patient databases,
  • State and national health surveys, and
  • Evaluation of models of care.

Inclusion of data and analyses of Long COVID by race/ethnicity, age, sex, and other factors are a CDC priority.

Related Research

Select examples of research on Long COVID conducted by CDC and partners

How can I Participate in Long COVID Research?

The National Institutes of Health (NIH) created the RECOVER Initiative, a research project that aims to understand how people recover from a SARS-CoV-2 infection and why some people do not fully recover and develop Long COVID or post-acute sequelae of SARS-CoV-2 (PASC). Anyone can participate in the RECOVER project, including those who have COVID-19 now, had COVID-19 before, or never had COVID-19. People of all races and ethnicities, genders, ages, and locations will be included in the research project to better understand how Long COVID affects people.

To learn more, including enrollment, visit the RECOVER web page.

Clinical Outreach and Communication Activity (COCA) Calls

The purpose of COCA continuing education opportunities is to increase clinicians’ knowledge of threats to the public’s health and provide information on clinical evaluation management strategies to address these threats. COCA continuing education is free. Learn about receiving continuing education (CE) credit for COCA calls.

CDC Publications

CDC is publishing the results of studies aimed at better understanding Long COVID and how best to support people experiencing Long COVID symptoms and related health problems.

Select CDC publications on Post-COVID Conditions and related topics:

Prospective Cohort Studies


Analysis of Electronic Healthcare Data


Health Surveys


Electronic Medical Chart Abstraction


Commentary