Stanford University announced Wednesday it would require weekly Covid testing for students, regardless of their vaccination status.
In a message to students, school officials revealed new safety protocols on campus beginning Aug. 15, citing the surge of the delta variant of the coronavirus across the country.
Returning students will be mandated to continue to wear face masks and get vaccinated, as well as undergo weekly testing for the coronavirus, regardless whether they are vaccinated or not, the school said. Students are expected to receive their test results within 24 hours.

Unvaccinated students were asked to arrive at the university a week before "in-person activities to complete entry testing, vaccination, and a period of restricted activity," the school said.
"We will continually assess these measures and will notify the entire campus community if changes are needed," Vice Provost Susie Brubaker-Cole wrote in the message. "In summary, we are confident these public health measures will protect our campus community."
The new safety measures mark a shift from the school's initial policy for vaccinated students. Last month, the university said "students living on campus or coming to campus frequently this summer" were no longer required to participate in Covid testing.
Stanford has since joined a small list of elite colleges that have required weekly coronavirus tests for vaccinated students, including Brown University, Harvard University and Princeton University.
Since March 2020, the university has recorded a total of 261 cumulative positive tests among students as of Sunday, according to the university's Covid-19 dashboard.
A NBC News analysis found that severe breakthrough cases were rare and unvaccinated people experienced significantly higher rates of severe illness and death.