A third dose of the Pfizer/BioNTech Covid-19 vaccine can "strongly" boost protection against the Delta variant -- beyond the protection afforded by the standard two doses, new data released by Pfizer suggests.Data posted online suggests that levels of antibodies that can target the coronavirus Delta variant grow fivefold in people 18 to 55 who get a third dose of the vaccine.Among people ages 65 to 85, the Pfizer data suggests that antibody levels that should protect against Delta grow 11-fold more than following a second dose.
