English study finds 50-60% reduced risk of COVID for double-vaccinated

LONDON - Fully-vaccinated people have an around 50 to 60% reduced risk of infection from the Delta coronavirus variant, including those who are asymptomatic, a large English coronavirus prevalence study found on Wednesday.

Imperial College London researchers said people who reported receiving two vaccine doses were half as likely to test positive for COVID-19, adjusting for other factors such as age, whether or not the people tested had COVID-19 symptoms. Focusing on those who had COVID-19 symptoms, effectiveness rose to around 59%, according to the study, which covered a period when the Delta variant completely displaced the previously dominant Alpha variant.