The 29-year-old celebrated the holiday with her roommate's family five days after nabbing her first Moderna vaccine shot. Quinn falls into an unlucky group of Americans exposed to the virus before their vaccine doses could offer them full protection. Krutika Kuppalli, an infectious-disease doctor in South Carolina, said most patients who tested positive after a first vaccine dose that she encountered had mild symptoms. Others who tested positive for coronavirus after their first vaccine dose have been trying to make sure their bad timing does not fuel vaccine hesitancy among friends and family. Her husband, who also tested positive, is just starting to recover his sense of taste and smell four months later.