Fully-vaccinated individuals have a 50 to 60% reduced risk of contracting infection from the Delta variant, including those who are asymptomatic, suggests a large coronavirus prevalence study by researchers from Imperial College London.

According to the researchers, fully-vaccinated individuals were found to be half as likely to test positive for COVID-19, after adjusting for factors such as age, irrespective of whether the tested individuals had COVID symptoms or not. Among people who had symptoms, the effectiveness was around 59%.

The researchers stated that the prevalence in unvaccinated individuals was 1.21%, which is 3-fold higher than the prevalence of 0.40% among the fully-vaccinated. They added that the viral load was also lower among the vaccinated individuals… (Reuters, August 4, 2021)