One dose of COVID vaccine halves transmission, study shows

New research by Public Health England reveals real-world impact of shots produced by Pfizer-BioNTech and AstraZeneca.

A single dose of the coronavirus vaccines deployed in England can cut transmission of COVID-19 within households by up to 50 percent, data from a new study showed on Wednesday. The Public Health England (PHE) research found that those who became infected three weeks after receiving their first jab of the Pfizer-BioNTech or AstraZeneca vaccines were between 38 and 49 percent less likely to pass the virus on to their household contacts compared to others who were unvaccinated. The shots also stop a vaccinated person developing symptomatic infection to start with, reducing the risk by about 60-65 percent from four weeks after one dose of either vaccine.