Credit: A man receives his first dose of the Pfizer vaccine against the coronavirus at the mass vaccination site at Ripken Baseball on May 05, 2021 in Aberdeen, Maryland. The man got a ride to the site from his landlord, Jorge Ardila-Medina of Fallston, Maryland, who has already taken several more car-loads of his tenants to be vaccinated. Maryland Governor Larry Hogan announced that more than 5 million people in Maryland have now received their first dose of the COVID-19 vaccine. (Photo by Chip Somodevilla/Getty Images)
Study: COVID-19 antibodies last longer, stay higher in those vaccinated after earlier infection
