Psaki described the official in question as a “mid-level employee” who does not have regular contact with Mr. Biden. The official is fully vaccinated and had taken a booster shot before they boarded Air Force One. The official did not experience any symptoms until Sunday when they received the positive result.

On Sunday, Mr. Biden had an antigen test and it was negative. The president was informed about the positive test by staff members and took a PCR test Monday. It was again negative. His next test was scheduled for Wednesday. Psaki stated that the CDC guidance does not require people who have been fully vaccinated to be quarantined after being exposed to COVID-19. He was therefore continuing his daily routine.


US President Joe Biden wave as he boarded Air Force One at Columbia Metropolitan Airport, West Columbia, South Carolina on December 17, 2021. MANDEL NGAN/AFP/Getty

Psaki stated that others in close contact with Air Force One staff were being contacted and advised by Psaki to take a COVID-19 testing, as per Centers for Disease Control and Prevention guidelines.

According to new data from the CDC, the president was exposed when the Omicron variant, which is highly transmissible in humans and has overtaken the Delta variant as the most prevalent strain of COVID-19 here. This variant is now responsible for more than 73% new infections. That’s nearly six times the number of cases compared to last week.

Omicron is the most common new case in the South, Central Midwest and Pacific Northwest.