It has been reported that : A single dose of a coronavirus vaccine can reduce household transmission of the virus by up to half, a study shows.
Those given a first dose of either the Pfizer or AstraZeneca vaccines - and who became infected three weeks later - were between 38% and 49% less likely to pass the virus on than unvaccinated people, PHE found.
Health Secretary Matt Hancock described the study's results as "terrific news".
He has urged "everybody to get their vaccines as soon as they are eligible".
In the study, protection against Covid was seen from about 14 days after vaccination, with similar levels of protection regardless of age of cases or contacts, PHE said in a statement.