Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Obtaining two vaccine doses remains the most effective way to ensure protection against the COVID-19 Delta variant of concern dominant in the UK today, according to a study from the University of Oxford.

Rendered picture depicting vaccine effectiveness against Covid-19 virus

Conducted in partnership with the Office of National Statistics (ONS) and the Department for Health and Social Care (DHSC), the study found that with Delta, Pfizer-BioNTech and Oxford-AstraZeneca vaccines still offer good protection against new infections, but effectiveness is reduced compared with Alpha.

Two doses of either vaccine still provided at least the same level of protection as having had COVID-19 before through natural infection; people who had been vaccinated after already being infected with COVID-19 had even more protection than vaccinated individuals who had not had COVID-19 before.

However, Delta infections after two vaccine doses had similar peak levels of virus to those in unvaccinated people; with the Alpha variant, peak virus levels in those infected post-vaccination were much lower.

Other key findings from the study:

  • A single dose of the Moderna vaccine has similar or greater effectiveness against the Delta variant as single doses of the other vaccines.
  • Two doses of Pfizer-BioNTech have greater initial effectiveness against new COVID-19 infections, but this declines faster compared with two doses of Oxford-AstraZeneca.
  • Results suggest that after four to five months effectiveness of these two vaccines would be similar – however, researchers say long-term effects need to be studied.
  • The time between doses does not affect effectiveness in preventing new infections, but younger people have even more protection from vaccination than older people.

Read the full story on the University of Oxford website

Similar stories

NHS garden in full bloom at RHS Chelsea Flower Show

The sun was shining for the RHS Chelsea Flower show press day earlier this week. One garden in particular bloomed particularly brightly, with the 'Finding Our Way: An NHS Tribute Garden' getting plenty of attention.

University of Oxford launches Podium Analytics Institute for Youth Sports Medicine and Technology

Oxford University has been selected as the home of the new Podium Analytics Institute for Youth Sports Medicine and Technology. This will be the world’s first academic Institute focused on young athletes’ safety and lifelong health and will combine Oxford’s longstanding tradition in sports and education with the very best of science, medicine, and technology.

QCovid highly commended for ‘best use of technology in Patient Safety’ at the 2021 HSJ Patient Safety Awards

Professor Julia Hippisley-Cox and her team in Nuffield Department of Primary Care Health Sciences have been Highly Commended in the ‘Best use of technology in Patient Safety’ category for the QCovid risk calculator at this year’s Health Service Journal Patient Safety Awards.

New guidelines to improve reporting standards of studies that investigate causal mechanisms

Researchers in the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS) have developed a new set of guidelines for reporting mediation analyses in health research.

Prestigious award for Oxford professor's diabetes work

A University of Oxford professor has been awarded the 2021 EASD-Novo Nordisk Foundation Prize for Excellence for his decades of effort to understand, prevent and combat type 1 diabetes.