FILE – In this March 29, 2021 file photo, a worker readies syringes with the Moderna COVID-19 vaccine in Metairie, La. Even people who have recovered from COVID-19 are urged to get vaccinated to avoid reinfection, especially amid the threat of the extra-contagious delta variant — and there’s growing evidence the shots offer those survivors bonus protection against mutants.(AP Photo/Gerald Herbert, File)