As well as being effective in providing high levels of protection, both the Pfizer and Oxford jabs appear to be capable of minimising the spread of coronavirus in people who have received two full doses.
The findings come from a study conducted by Public Health Scotland and the University of Glasgow, which assessed 300,000 NHS workers and their households between 8 December and 3 March.
For people living with vaccinated and unvaccinated healthcare workers, the likelihood of catching Covid-19 was reduced by at least 30 per cent after the health workers had received a single dose.
Given that people living with healthcare workers could also catch the virus from other sources, researchers said the 30 per cent figure is a low estimate.
For those living with workers who had both doses of either vaccine, their risk of infection was found to be at least 54 per cent lower.
Dr Dianne Stockton, the Public Health Scotland lead for the Covid-19 Vaccination Surveillance Programme, said the results are “encouraging”, but stressed this should not make the public complacent.
“Despite this good news, it is important to remember that infection prevention and control practices in healthcare settings remain of paramount importance, as do the mitigations to prevent spread in our daily lives," she said.
Professor Keith Neal, an epidemiologist in infectious diseases at the University of Nottingham, said: “It is not surprising that vaccination prevents transmission as we have increasing evidence the vaccines can stop disease and asymptomatic infection and you can only spread an infection if you have that infection.”
More than 23.3 million first doses have been administered across the UK, while 1.4 million people have received both jabs.
The results of the study come as new estimates from the Office for National Statistics show that the number of people infected with coronavirus is continuing to fall across England – though cases appear to be levelling off in both Northern Ireland and Scotland.
An estimated 1 in 270 individuals in England were infected with the virus between 28 February and 6 March, according to the latest infection survey published by the ONS – the equivalent of 200,600 people.
The figure is down from around one in 220, or 248,100 people, for the previous week, and is the lowest figure since the week to 24 September, when the estimate stood at one in 470.
Meanwhile, government scientific advisers said the latest R rate for the UK ranges between 0.6 and 0.8 – down from 0.7 and 0.9 last week.
Under the current estimates, for every 10 individuals who catch Covid, a further six to eight people will become infected.
The government’s Scientific Advisory Group for Emergencies said: “While the epidemic continues to decrease nationally, there may be more variation in transmission locally, with slower rates of decline in some areas and communities.”
Despite the falling rates, the number of cases in England remains high compared to last summer. In the week to 25 August, around one in 2,000 people had coronavirus.
The latest data for Wales shows around one in 365 people are estimated to have had Covid-19 between in the seven days to 6 March – down from one in 285 the week before.
In Northern Ireland, around one in 310 people were infected, up from one in 325. The estimate for Scotland was around one in 320 people, an increase from one in 335.
The percentage of people testing positive has decreased in a majority of regions in England but there were “early signs of a possible increase ... in the southeast and southwest,” the ONS said.
The ONS data is based on swabs taken from people in households, regardless of whether they have symptoms or not. It does not include care homes, hospitals and other institutional settings.
Because of this, it is seen as a more accurate reflection of the current state of the epidemic in the UK.
Test and trace data released on Thursday showed a 34 per per cent decrease in cases from the previous week, but the system does not account for asymptomatic infections within the population – a key driver of the Covid crisis.
Separately, provisional data from the Ministry of Justice (MoJ) has shown that, between 16 March 2020 and 28 February 2021, 118 prisoners died after testing positive for coronavirus.
Of these, the deaths of 93 inmates were suspected or confirmed to have been caused by coronavirus. The deaths occurred in 54 prisons across England and Wales, the MoJ report said.
Some 14,480 prisoners have tested positive for Covid-19 since the start of the pandemic, in 127 jails. Some 106 of the inmates were child criminals in youth custody.
A total of 125,343 people have now died from coronavirus in the UK after 175 further fatalities were reported on Friday. The government said that new 6,609 infections had also been confirmed.
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