Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
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.
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.
Travel requirements to enter the United States are changing, starting November 8, 2021. More information is available here.

Post-COVID Conditions: CDC Science

Post-COVID Conditions: CDC Science

How CDC is using science to learn more about post-COVID conditions (or long COVID)

Updated May 5, 2022

CDC is analyzing healthcare data, partnering with clinicians, and working with researchers to learn more about post-COVID conditions (Long COVID).

Post-COVID conditions (PCC, or Long COVID) are a wide range of new, returning, or ongoing health problems people can experience four or more weeks after first being infected with the virus that causes COVID-19.

What CDC Is Doing to Learn about Post-COVID Conditions

CDC and partners are doing research on post-COVID conditions in a variety of populations and settings. These partnerships are essential for expanding the base of evidence needed for addressing post-COVID conditions. CDC and its partners are working to:

  • Characterize and assess post-COVID conditions to provide estimates on the prevalence (number) and incidence (frequency) of people experiencing post-COVID conditions by demographic group, symptom, and new diagnosis. This will allow us to
    • Identify risk factors to better understand how to prevent post-COVID conditions.
    • Identify groups disproportionately affected by post-COVID conditions.
    • Assess the burden (health and financial costs) of post-COVID conditions.
  • Identify successful interventions to prevent and lessen the effect of post-COVID conditions. This research includes
    • Assessing if COVID vaccinations reduce the occurrence of post-COVID conditions.
    • Promoting equity in healthcare access and utilization for people with post-COVID conditions.
  • Disseminate clinical guidance and other education materials for healthcare providers, patients, and the public to improve understanding of post-COVID conditions and reduce stigma.
Science at CDC
Scientific articles and manuscripts about COVID-19 and post-COVID conditions

MMWR COVID-19 ReportsCDC Scientific Publications on COVID-19

CDC and partners are collecting and analyzing information about post-COVID conditions 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 post-COVID conditions
  • Medical chart abstraction to collect data on the health and medical care of patients with post-COVID conditions
  • Analyses of electronic healthcare data and large patient databases
  • State and national health surveys
  • Evaluation of models of care

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

Related Research

Select examples of research on post-COVID conditions conducted by CDC and partners

Interim Clinical Guidance

CDC is sharing information with healthcare providers to support evaluation and care of patients with post-COVID conditions.

Clinical Outreach and Communication Activity (COCA) Calls

The purpose of COCA continuing education opportunities is to increase clinicians’ knowledge and competencies of threats to the public’s health, their effects on human populations, and evaluation and management strategies of 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 post-COVID conditions and how best to support people experiencing post-COVID conditions and 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