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.

SARS-CoV-2 Viral Culturing at CDC

SARS-CoV-2 Viral Culturing at CDC
Updated Dec. 29, 2020

SARS-CoV-2, the virus that causes COVID-19, was isolated in the laboratory and is available for research by the scientific and medical community.

One important way that CDC has supported global efforts to study and learn about SARS-CoV-2 in the laboratory was by growing the virus in cell culture and ensuring that it was widely available. Researchers in the scientific and medical community can use virus obtained from this work in their studies.

CDC is using SARS-CoV-2 in various ways, including the following:

SARS-CoV-2 strains supplied by CDC and other researchers can be requested, free, from the Biodefense and Emerging Infections Research (BEI) Resources Repositoryexternal icon by established institutions that meet BEI requirements. These requirements include maintaining appropriate facilities and safety programs, as well as having the appropriate expertise. BEI supplies organisms and reagents to the broader community of microbiology and infectious disease researchers.

Some areas of COVID-19 research that public and academic institutions may study with the SARS-CoV-2 strains include:

  • Antiviral research:external icon This includes research aimed at testing the ability of existing or experimental antiviral medications to treat or prevent infection with SARS-CoV-2.
  • Vaccine development:external icon Scientists in public, private sector, and academic institutions continue to work together to develop safe and effective COVID-19 vaccines. Learn more about currently authorized vaccines in the United States.
  • Pathogenesis research: This includes research to determine the various ways the virus can be transmitted to a host, the severity of illness it causes in a host, how much virus is produced in the body, and what organs the virus can spread to within the body.
  • Virus stability research:external icon This is research that indicates how long the virus can survive under certain conditions, such as how long the virus can survive and remain infectious on surfaces, and the temperatures at which it can survive.


  • On January 20, 2020, CDC received a clinical specimen collected from the first reported U.S. patient infected with SARS-CoV-2. CDC immediately placed the specimen into cell culture to grow a sufficient amount of virus for study.
  • On February 2, 2020, CDC generated enough SARS-CoV-2 grown in cell culture to distribute to medical and scientific researchers.
  • On February 4, 2020, CDC shipped SARS-CoV-2 to the BEI Resources Repository.
  • An article discussing the isolation and characterization of this virus specimen is available in Emerging Infectious Diseases.