News Release

Vaccinated groups at highest risk of Covid-19 hospitalisation and death identified using new QCovid tool

Peer-Reviewed Publication

University of Oxford

Researchers from the University of Oxford have today reported on findings on the vaccinated people who are at greatest risk from severe Covid-19 leading to hospitalisation or death from 14 days post the second dose vaccination, when substantial immunity should be expected.

In a paper published in the British Medical Journal, they write that by updating the QCovid tool developed in 2020, which directly influenced UK policy in February 2021, adding 1.5 million people in February 2021 to list of those advised to shield, they are able to identify groups more at risk of hospitalisation or death from Covid-19.

They used national linked datasets from general practice, national immunisation and SARS-CoV-2 testing, death registry and hospital episode data, in order to analyse a sample of over 6.9m vaccinated adults, of whom 5.2m had both vaccines doses, which was representative of the UK population as a whole. This sample included 2,031 Covid-19 deaths and 1,929 Covid-19 related hospital admissions, of which 81 deaths and 71 admissions occurred 14 or more days after the second vaccine dose.

Based on this, the researchers have developed cumulative risk scores to calculate people’s risk of hospitalisation or death from Covid-19 following one, or two vaccination doses. These scores take into account factors including age, sex, ethnic group and the background rate of Covid infections, and in particular highlight an elevated risk to:

  • Those who are immunosuppressed as a result of chemotherapy, a recent bone marrow or solid organ transplant, or HIV/AIDS
  • People with neurological disorders, including dementia and Parkinson’s
  • Care home residents, and those with chronic disorders including Down’s Syndrome

Julia Hippisley-Cox, Professor of Clinical Epidemiology and General Practice at the University of Oxford, co-author of the paper, said:

‘The UK was the first place to implement a vaccination programme and has some of the best clinical research data in the world. We have developed this new tool using the QResearch database, to help the NHS identify which patients are at highest risk of serious outcomes despite vaccination for targeted intervention. This new tool can also inform discussions between doctors and patients about the level of risk to aid shared decision making.’

The researchers report that there were relatively few COVID-19 related hospitalisations or deaths in the group who had received the second dose of any vaccine, meaning that the study lacked the statistical power to determine if the groups listed above are more, or less, at risk following a second vaccine dose compared with following the first dose.

Furthermore, they did not distinguish between type of vaccination offered, and acknowledge that their study may have been limited by factors such as exposure, as occupation for example is not something that is often recorded in general practice or hospital records.

Aziz Sheikh, Professor of Primary Care Research & Development and Director of the Usher Institute at The University of Edinburgh and a co-author of the paper, said:

‘This enormous national study of over 5 million people vaccinated with 2 doses across the UK has found that a small minority of people remain at risk of Covid-19 hospitalisation and death.  Our risk calculator helps to identify those who remain most at risk post-vaccination.’

‘Our new QCovid tool, developed with the help of experts from across the UK, has been designed to identify those at high risk who may benefit from interventions such as vaccine booster doses or new treatments such as monoclonal antibodies, which can help reduce the risk of progression SARS-CoV-2 infection to serious Covid-19 outcomes.’

The researchers hope that these data can be used in a variety of health and care settings to inform those more likely to be at risk, and potentially help to prioritise those identified for further trials of vaccines, boosters or future preventative therapies.

Prof. Hippisley-Cox concludes:

‘Individual risk will always depend on individual choices as well as the current prevalence of the disease, however we hope that this new tool will help shared decision making and more personalised risk assessment.’

ENDS

An embargoed media briefing, hosted by the UK Science Media Centre, will be held at 09:00 (UK- UTC+1). To sign up for this briefing, please email: lethbridge@sciencemediacentre.org

For requests for media interviews, please contact the University of Oxford News Office: news.office@admin.ox.ac.uk

+44 1865 280528

About the study:

This study was funded by the National Institute for Health Research.

An infographic is also available, please email news.office@admin.ox.ac.uk for a copy.

About the Nuffield Department of Primary Health Care Sciences

The Nuffield Department of Primary Care Health Sciences has been one of the world’s most important primary care centres for almost 20 years. With research led by internationally renowned scientists; many of whom are practising GPs, it also has academics from a range of non-medical disciplines including the social sciences and humanities.

About the Medical Sciences Division

The Medical Sciences Division is an internationally recognised centre of excellence for biomedical and clinical research and teaching and is the largest of the four academic divisions within the University. The other three divisions are Humanities, Mathematical, Physical and Life Sciences and Social Sciences.

Over 5000 academics, researchers, NHS clinicians and GPs, and administrative staff, 1500 graduate and 1600 undergraduate students, together contribute to its extensive and exemplary research, teaching and clinical portfolios.

It aims to be the best university biomedical institution in Europe and amongst the best five biomedical institutions in the world, and has been ranked number one for the last ten years in the Times Higher Education World University Rankings for clinical, pre-clinical and health sciences - the only non-North American institution to be top-ranked by THE in any subject discipline.

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the fifth year running, and at the heart of this success is our ground-breaking research and innovation.

Oxford is world-famous for research excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 200 new companies since 1988. Over a third of these companies have been created in the past three years.


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.