Before revision:  We find that , even with relatively high levels of vaccine coverage , reopening may lead to infection prevalence well above current ambient community levels. As many students attending urban universities belong to vaccine hesitant groups, asymptomatic cases present increased collateral risk to these students' households and communities. We recommend that such universities ensure that most of the campus population is vaccinated, perform asymptomatic screening testing, limit the number of individuals on-campus, and encourage students to socialize safely.
After revision:  We find that mRNA vaccine coverage above 80\% makes it possible to safely reopen to in-person instruction. If vaccine coverage is 100\%, then our model indicates that facemask use is not necessary. Our simulations with vaccine coverage below 70\% exhibit a right-skew for total infections over the semester, which suggests that high levels of infection are not exceedingly rare with campus social connections the main transmission route. Less effective vaccines or incidence of new variants may require additional intervention such as screening testing to reopen safely.