Pfizer coronavirus vaccine reduces transmission after one dose, UK study finds
- Researchers found a fourfold decrease in the risk of asymptomatic Covid-19 infection among health workers who have been jabbed for more than 12 days
- Earlier, a key Israeli study showed that two doses of the Pfizer shot cut symptomatic cases by 94 per cent across all age groups
Researchers analysed results from thousands of Covid-19 tests carried out each week as part of hospital screenings of health care staff in Cambridge, eastern England.
“Our findings show a dramatic reduction in the rate of positive screening tests among asymptomatic health care workers after a single dose of the Pfizer-BioNTech vaccine,” said Nick Jones, an infectious diseases specialist at Cambridge University Hospital, who co-led the study.
After separating the test results from unvaccinated and vaccinated staff, Jones’ team found that 0.80 per cent tests from unvaccinated health care workers were positive.
This compared with 0.37 per cent of tests from staff less than 12 days post-vaccination – when the vaccine’s protective effect is not yet fully established – and 0.20 per cent of tests from staff at 12 days or more post-vaccination.