February 18, 2021
People who are fully vaccinated against the coronavirus do not need to quarantine if they are exposed to COVID-19 and meet certain criteria, according to the U.S. Centers for Disease Control and Prevention.
The agency's new guidance, issued last week, defines fully vaccinated as people who have gone at least two weeks since receiving their second doses of the Pfizer or Moderna vaccines. The same time frame also will apply to any future single-dose vaccines, like the Johnson & Johnson shot awaiting authorization.
Vaccinated people seeking to skip quarantine also must meet the following criteria:
•No more than three months have passed since they received their final COVID-19 doses.
•They must have remained asymptomatic since their potential COVID-19 exposures.
Everyone else is instructed to quarantine for one to two weeks to determine whether they develop symptoms. The shorter duration requires a negative COVID-19 test.
The three-month criteria mirrors the guidance given to people with natural immunity to the coronavirus, NBC reported. Anyone who has recovered from COVID-19 within the previous 90 days also does not need to quarantine.
The CDC acknowledged it updated the guidelines despite additional research being needed to determine whether vaccinated people can still transmit the disease to others.
"There is currently limited information on how much COVID-19 vaccines might reduce transmission or how long the duration of protection lasts," CDC spokesperson Kristen Nordlund told CNN.
"It's important to note that CDC is not suggesting someone who is vaccinated cannot spread COVID-19 within the first 90 days of being fully vaccinated, nor are we suggesting that expected protection from COVID-19 vaccines wears off after 90 days."
Despite this uncertainty, the CDC stressed that asymptomatic cases are thought to be less easily transmitted.
"Although the risk of SARS-CoV-2 transmission from vaccinated persons to others is still uncertain, vaccination has been demonstrated to prevent symptomatic COVID-19; symptomatic and pre-symptomatic transmission is thought to have a greater role in transmission than purely asymptomatic transmission," the CDC said.