Published: 21 October 2021
Two vaccine doses offer very high levels of protection against death should you contract the COVID-19 Delta variant, according to a landmark study conducted across Scotland.
The study is the first to provide results on the effectiveness of COVID vaccines against Delta - the UK’s dominant strain - using real-world data from an entire country.
It is part of the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) project, jointly funded by NIHR and UK Research and Innovation (UKRI) to look into the efficacy of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines.
The research team from Universities of Edinburgh and Strathclyde, as well as Public Health Scotland, analysed anonymised linked patient data to track the pandemic and the vaccine roll out in real time.
Between 1 April and 27 September 2021, 115,000 people tested positive for COVID-19 in the community out of Scotland’s 5.4m population and 201 deaths were recorded due to the virus.
Mortality figures were cross-referenced with positive PCR tests taken from people who were not in hospital. This showed that for those double jabbed, the Pfizer-BioNTech vaccine reduced the risk of dying by 90% - compared with those who were unvaccinated - while the Oxford-AstraZeneca efficacy was 91%.
To increase confidence in these early findings, published in the New England Journal of Medicine, the researchers are keen for the study to be repeated in other countries and settings, and with longer follow-up time after full vaccination.
Professor Aziz Sheikh, Director of the University of Edinburgh’s Usher Institute and EAVE II study lead, said: “With the Delta variant now the dominant strain in many places worldwide and posing a higher risk of hospitalisation than previous variants seen in the UK, it is reassuring to see that vaccination offers such high protection from death very shortly after the second dose.
“If you still have not taken up your offer to be vaccinated, I would encourage you to do so based on the clear benefits it offers.”
Previous studies using EAVE II have shown how vaccines had led to a substantial reduction in Scottish hospital admissions while illustrating that some groups were still at risk of complications from COVID-19 despite having had one or two jabs.
Read more about the latest study in the New England Journal of Medicine paper.