The Daily Pennsylvanian is a student-run nonprofit. Please support us by disabling your ad blocker on our site. Image 04-14-21 Penn Vaccination Site Covid-19 Vaccine Mask Nurse.jpg By Chase Sutton 04/19/21 8:20pm Penn Institute of Immunology found that people who have recovered from COVID-19 may only need a single dose of the vaccine. PennConnects