The United States Centers for Diseases Control and Prevention decided to shorten the isolation period to half for those people contacted with the coronavirus.

The CDC said that just five days after their positive test results those without symptoms could safely resume mixing with others.

Furthermore, the CDC reduced the time that close contacts must quarantine if they are vaccinated to 5 days, and they do not have to be isolated if they have gotten a booster dose.

Growing research suggests that the virus is most contagious two days before and three days after symptoms appear, according to the CDC. Those who are still experiencing symptoms after five days are advised to stay at home.

Dr. Antony Fauci, director of the National Institute of Allergy and Infectious Diseases and Chief Medical Advisor to President Joe Biden, said Monday morning that it would be "reasonable" to require vaccination of those who board domestic flights, a requirement that has so far only been requested of international passengers, but that no decision has been made.