English data shows vaccines cut household COVID-19 transmission by up to a half

Shots reducing the risk of developing an infection by around 60% to 65% from four weeks after one dose

COVID-19 vaccines deployed in England can cut transmission of the coronavirus by up to a half, data from Public Health England showed on Wednesday, in addition to the protection the shots offer against symptomatic infection.

News research showed that people who became infected with the coronavirus three weeks after receiving one dose of Pfizer or AstraZeneca vaccine were between 38% to 49% less likely to pass it on to household contacts compared to those who were unvaccinated.

The shots also stop a vaccinated person from developing an infection to start with, reducing the risk by around 60% to 65% from four weeks after one dose of either vaccine.

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"This study is the most comprehensive real-world data showing they also cut transmission of this deadly virus," health minister Matt Hancock said.

"It further reinforces that vaccines are the best way out of this pandemic as they protect you and they may prevent you from unknowingly infecting someone in your household."

The study included over 57,000 contacts from 24,000 households in which there was a lab-confirmed case that had received a vaccination, Public Health England (PHE) said, compared with nearly 1 million contacts of unvaccinated cases.