Single dose of vaccine cuts Covid spread by half: Study
Protection against coronavirus seen from about 14 days after vaccination
Asingle dose of either the Oxford/ Astrazeneca or Pfizer/biontech vaccines have been found to cut Covid-19 transmission rates by up to half, according to a new Public Health England (PHE) study on Wednesday.
Those given a first dose of either of the two vaccines currently being administered by the National Health Service (NHS) and who became infected with SARS-COV-2 — the coronavirus which causes Covid-19 — three weeks later were between 38 and 49 per cent less likely to pass the virus on than unvaccinated people.
The PHE also found that protection against Covid-19 was seen from about 14 days after vaccination, with similar levels of protection regardless of age of cases or contacts.
“This is further evidence that the vaccine protects you and those around you,” said UK Health Secretary Matt Hancock. The study, yet to be fully peer-reviewed, included more than 57,000 contacts from 24,000 households in which there was a lab-confirmed coronavirus case that had received a vaccination, compared with nearly 1 million contacts of unvaccinated cases.
Contacts were defined as secondary cases of coronavirus if they tested positive two to 14 days after the initial household case. Most of the people in the study were under the age of 60.
The protection against transmission was found on top of the reduced risk of a vaccinated person developing symptomatic infection in the first place, which has previously been found to be 60 to 65 per cent — four weeks after one dose of either vaccine.