WEST LAFAYETTE, Ind. — Starting Monday, Purdue University will again require face masks for everyone indoors on campus, regardless of vaccination status. The policy update includes students, employees and visitors to campus. The university said Friday that Tippecanoe County is among the areas of substantial transmission that the CDC recommended to return to masks for vaccinated and unvaccinated people as part of an effort to slow the spread of the very contagious delta variant of COVID-19.