Nurse Cindy Mendez wearing a protective mask holds a syringe with a dose of Pfizer-BioNTech COVID-19 vaccine during the coronavirus disease (COVID-19) pandemic, at NYC Health + Hospitals Harlem in the Manhattan neighborhood in New York, New York, February 25, 2021.
Jeenah Moon | Reuters
LONDON – A single dose of a coronavirus vaccine can halve transmission within a household, according to a study by Public Health England.
People who became infected with the coronavirus three weeks after receiving a single dose of the Pfizer-BioNTech or AstraZeneca-Oxford University vaccine were between 38% and 49% less likely to pass the virus to their household contacts than those who did were not vaccinated. , revealed the PHE study.
Protection was observed approximately 14 days after vaccination, with similar levels of protection regardless of the age of the cases or contacts.
This protection is in addition to the reduced risk for a vaccinated person of developing a symptomatic infection in the first place, which is about 60% to 65% – four weeks after a dose of either vaccine, PHE noted. . Having both doses of a coronavirus vaccine (the time between doses can be up to 12 weeks in the UK) provides an even higher level of protection against Covid infection.
British Health Secretary Matt Hancock hailed the study’s findings as “excellent news”. “We already know that vaccines save lives and this study is the most comprehensive of the actual data showing that they also reduce the transmission of this deadly virus.”
“This further reinforces the fact that vaccines are the best way out of this pandemic because they protect you and they can prevent you from unknowingly infecting someone in your household.”
“I urge everyone to get vaccinated as soon as they are eligible and to make sure you get your second dose for the strongest protection possible,” he added.
The Pfizer-BioNTech and AstraZeneca vaccines are widely deployed in the UK, with the Moderna vaccine also now being added to the vaccination schedule.
The rollout of the vaccine has been a remarkable success in Britain and a beacon of hope after the destruction of the pandemic, which has caused more than 127,000 deaths so far in the country.
The UK has seen cases, hospitalizations and deaths drop dramatically since its deployment began in December, alongside strict lockdown measures. To date, nearly 34 million UK adults have received a first dose of a vaccine and more than 13 million have received two doses, according to government data.
The PHE study noted that households are areas at high risk of transmission and provide early evidence of the impact of vaccines on preventing transmission. Similar results could be expected in other settings with similar transmission risks, such as shared housing and prisons, he noted.
The study, which is a pre-print that has not yet been peer-reviewed, included more than 57,000 contacts from 24,000 households in which there was a laboratory-confirmed case of coronavirus that had received a vaccination, against nearly a million contacts of unvaccinated cases. .
By linking case and household contact data to vaccination status, the study compared the probability of transmission from a vaccinated case to an unvaccinated case.
PHE is also undertaking separate studies on the effect of vaccination on transmission in the general population.