Home / Health / Covid: One dose of vaccine halves transmission – study

Covid: One dose of vaccine halves transmission – study

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.
UK Health Secretary Matt Hancock 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, PHE said in a statement.

It added that this protection was on top of the reduced risk of a vaccinated person developing symptomatic infection in the first place which is around 60 to 65% – four weeks after one dose of either vaccine.

Dr Mary Ramsay, head of immunisation at PHE, said: “Vaccines are vital in helping us return to a normal way of life. Not only do vaccines reduce the severity of illness and prevent hundreds of deaths every day.”

Households are high-risk settings for transmission, meaning the study provides early evidence on the impact of vaccines in preventing onward transmission, PHE said.