"In the absence of any national strategy for tackling the coronavirus pandemic, colleges and universities in the United States are on their own when it comes to deciding whether and how to bring students back for the autumn term, which has already started for some institutions. Many are relying on their own experts, resulting in a wide range of approaches, from telling students to attend online classes from home to bringing everyone back and testing them three times a week. Some are welcoming limited numbers of students with a face mask stamped with the university’s mascot, a bottle of hand sanitizer and plans to test only a fraction of people on campus. It all amounts to a gigantic, unorganized public-health experiment — with millions of students and an untold number of faculty members and staff as participants. Bringing so many university students to crowded campuses is uniquely risky in the United States, which has seen the largest number of deaths to COVID-19 of any country and has active community transmission of SARS-CoV-2, the virus responsible for the pandemic. Other large countries with surging infection rates, such as India and Brazil, are not opening up campuses to the same degree. According to the College Crisis Initiative, a research project at Davidson College in North Carolina, more than 1,000 four-year colleges and universities in the United States will bring students back to campus in some form, with 45 operating “fully in person”, another 446 as “primarily in person”, and nearly 600 offering various combinations of online and in-person classes as of 7 August (see ‘Back to school’). But plans change daily, with many universities that boldly planned to hold in-person classes deciding at the last minute to switch to virtual versions."