Vaccination reduces Covid-19 hospital admissions, NIHR study suggests
Vaccination has been linked to a substantial reduction in the risk of Covid-19 admissions to Scotland’s hospitals, landmark research suggests.
The Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) project was funded by round 2 of the joint NIHR and UKRI rapid COVID-19 funding call. The study builds on EAVE I – one of a collection of NIHR hibernating studies reactivated once the pandemic hit.
It is the first to describe across an entire country the effect of the Pfizer-BioNTech and Oxford-AstraZeneca jabs in the community on preventing severe illness resulting in hospitalisation. Previous results about vaccine efficacy have come from clinical trials.
By the fourth week after receiving the initial dose, the Pfizer-BioNTech and Oxford-AstraZeneca vaccines were shown to reduce the risk of hospitalisation from Covid-19 by up to 85 per cent and 94 per cent, respectively.
Among people aged 80 years and over, one of the highest risk groups, vaccination was associated with an 81 per cent reduction in hospitalisation risk in the fourth week, when the results for both vaccines were combined.
As part of the EAVE II project, which uses patient data to track the pandemic and the vaccine roll out in real time, researchers from the Universities of Edinburgh, Strathclyde, Aberdeen, Glasgow and St Andrew’s and Public Health Scotland (PHS) analysed a dataset covering the entire Scottish population of 5.4 million.
Data on vaccine effect was gathered between 8 December 2020 and 15 February 2021. During this period, 1.14 million vaccines were administered and 21 percent of the Scottish population had received a first dose based on Scottish Government prioritisation.
The Pfizer-BioNTech vaccine has been received by some 650,000 people and 490,000 have had the Oxford- AstraZeneca vaccine.
Researchers analysed data for every week during this period – including GP records on vaccination, hospital admissions, death registrations and laboratory test results – and compared the outcomes of those who had received their first jab with those who had not.
The preliminary results have been posted on the SSRN preprint server and submitted to a journal to undergo peer review.
The study team says the findings are applicable to other countries that are using the Pfizer-BioNTech and Oxford-AstraZeneca vaccines. They caution that the data does not allow for comparisons between the two.
Lead researcher Professor Aziz Sheikh, Director of the University of Edinburgh’s Usher Institute, said: “These results are very encouraging and have given us great reasons to be optimistic for the future. We now have national evidence – across an entire country – that vaccination provides protection against Covid-19 hospitalisations.”
“Roll-out of the first vaccine dose now needs to be accelerated globally to help overcome this terrible disease.”
Professor Chris Whitty, Chief Medical Officer for England and co-lead for the National Institute for Health Research (NIHR), said: "This research provides encouraging early data on the impact of vaccination on reducing hospitalisations.”