The Pfizer/BioNTech COVID-19 vaccine is highly effective at preventing infection and symptomatic disease from the Delta variant among 12- to 18-year-olds, research conducted in Israel shows. The findings, published in the New England Journal of Medicine, will likely provide further reassurance the shot is effective against the variant among younger people as the U.S. drug watchdog considers authorising use of the vaccine on children as young as five. The study found the estimated vaccine effectiveness against documented COVID-19 infection in adolescents was 90%, and 93% against symptomatic C...