NEW HAVEN, Conn. (AP) — Yale University has announced that it will delay the start of its spring semester for undergraduates and the graduate school of arts and sciences by a week amid the latest surge in COVID-19 cases.

In an email sent Wednesday night to the Yale community, school President Peter Salovey and University Provost Scott Strobel said the school also will shorten spring break from two weeks to one week.

Yale’s spring semester will now begin online on Jan. 25, with in-person classes starting on Feb. 7, the officials said. Students must be back on campus no later than Feb. 4, according to the email, which was first reported by the Yale Daily News.

Yale plans to use the week of Jan. 18 to administer online makeup exams for students who were unable to complete their finals in December. In addition, the school canceled in-person exams for the fall semester on Dec. 18.

Spring break will now run from March 19 to March 28.

“Of course, the past months have been difficult for many of us, but we also displayed unmatched strength, kindness and ingenuity. We are grateful for your tremendous efforts,” Salovey and Strobel wrote. “Together, we will continue to navigate through this extraordinary moment in history.”

The changes to the calendar were made after the university reported 67 cases of COVID-19 on Dec. 20.

The seven-day rolling average of daily new cases in Connecticut has risen from 1,525 new cases on Dec. 7 to 2,729 on Dec. 21, according to Johns Hopkins University Center for Systems Science and Engineering.

The state reported that 821 people were hospitalized Wednesday with COVID-19. The governor’s office was set to release its weekly accounting of COVID-19 deaths on Thursday afternoon.

In response to the new cases, the state Department of Public Health has rescinded guidance that would have allowed vaccinated high school athletes in the state to stop wearing masks during competition beginning on Friday.

Dr. Manisha Juthan, the state’s public health commissioner, said in a statement that the rapid rise in cases and the omicron variant “forced us to reconsider that assessment.”

“Guidance that has been in place for winter sports throughout this season will remain in place,” Juthan said. “In line with our neighboring states of Massachusetts and Rhode Island, DPH is advising that all participants continuously wear a mask over the nose and mouth during all indoor athletic activities to help reduce the spread of COVID-19 in our state and region.”