Duke University, already operating under lockdown to combat a rise in coronavirus infections, on Tuesday reported 231 cases from last week, almost as many as the school had the entire fall semester.

“This was the highest number of positive cases reported in a single week,” the school said in a statement. “The individuals who tested positive have been placed in isolation, while those identified as potential contacts have been placed in precautionary quarantine.”

The school issued a “stay in place” order Saturday, requiring students living in Duke-provided housing to remain in their residence hall room or apartment at all times except for essential activities related to food, health or safety. Students living off campus are required to stay there except for a few exceptions.

Rush events by unaffiliated fraternities appear to be the main culprit for the outbreak.

“This (stay-in-place) action is necessary to contain the rapidly escalating number of COVID cases among Duke undergraduates, which is principally driven by students attending recruitment parties for selective living groups,” the university said.

Also in the news: 

►The White House said Tuesday that more than 22 million doses of COVID-19 vaccines will be distributed in the next seven days, a new high that would send the daily average over 3 million for the first time. Of that total, 16 million doses would be distributed to the states and the rest to federally administered programs, including mass vaccination sites, retail pharmacies and community health centers.

►More states are allowing all adults to get vaccinated. Mississippi joined Alaska on Tuesday in opening the vaccine eligibility flood gates. Ohio’s governor said Tuesday the vaccine will be available to anyone in the state 16 and older by the end of March, and Connecticut is preparing to open to all 16 and over starting April 5.

►The seven-day rolling average for daily new cases in the U.S. decreased over the past two weeks from 67,570 on March 1 to 55,332 on Monday, while the average for daily deaths on those same dates dropped from 1,991 to 1,356, according to Johns Hopkins University data.

►Rep. John Katko, R-N.Y., is calling on President Joe Biden to declare “National COVID-19 Vaccination Awareness Day” as a one-time federal holiday to promote and encourage vaccination efforts nationwide.

►China has approved a fifth vaccine for emergency use, a three-dose vaccine with one month each between shots. China has been slow in vaccinating its population of 1.4 billion people, with 65 million doses administered. Most went to health care workers, those working at the border or customs, and specific industries.