Harvard Business School is returning to remote instruction for its first-year students in an effort to curb an increase in breakthrough COVID-19 infections.
Online instruction will take place through Oct. 3 and coronavirus testing will increase to three times a week, Mark Cautela, a spokesman for the business school, said in a statement. Some second-year MBA students will also take remote classes.
Harvard University reported 74 positive tests among students, faculty, and staff in the six-day period that ended Saturday. Of those infections, 60 — or 81 percent — were among graduate students.
Harvard’s population is highly vaccinated — 95 percent of students and 96 percent of faculty and staff are fully immunized, according to university figures.
The majority of transmissions at the business school have taken place off campus among students who may not have complied with indoor mask recommendations, Cautela said.
“Contact tracers who have worked with positive cases highlight that transmission is not occurring in classrooms or other academic settings on campus,” Cautela said. “Nor is it occurring among individuals who are masked.”
Along with increased testing frequency, Harvard has “asked all students to eliminate unmasked indoor activities, limit in-person interactions with others outside their household, move all group gatherings online, and cancel group travel,” Cautela said.
Last November, administrators shifted classes from a hybrid format to fully remote instruction as cases rose among students.
Other universities have struggled to minimize transmission among students. Earlier this month, the University of Massachusetts Amherst reported an outbreak of nearly 400 cases and recorded 100 cases from Sept. 15 to 21.
Globe correspondent Julia Carlin contributed to this report.