By Karen Weintraub
Six months after getting a second dose of the Pfizer-BioNTech vaccine (click here) as part of a 46,000-person clinical trial, volunteers remained more than 90% protected against symptomatic COVID-19 and even better protected against severe disease, a new company study found.
Out of 927 trial participants who fell ill with COVID-19 more than a week after their second dose, only 77 had received the active vaccine, compared with 850 who got a placebo.
There were no serious safety concerns among the 12,000 volunteers who are at least six months past their second dose, according to the newly released findings. Many, however, did have typical, short-term side effects such as fatigue and sore arms.
The study also showed that the vaccine is effective against a virus variant called B.1.351, first identified in South Africa....