Consequences of missed COVID vaccines: SAIL Databank contributes to first all-UK study of 67 million people

The first research study of the entire UK population highlights gaps in COVID-19 vaccine coverage. Between a third and a half of the populations of the four UK nations had not had the recommended number of COVID vaccinations and boosters by summer 2022.

Findings suggest that more than 7,000 hospitalisations and deaths might have been averted in summer 2022 if the UK had had better vaccine coverage, according to the paper, published in The Lancet.

The research sheds light on vaccine uptake and hesitancy and could inform policy-makers as public health campaigns for COVID-19 and flu jabs continue to be rolled out this winter.

SAIL Databank, based at Population Data Science at Swansea University in Wales, was used to provide de-identified data, that combined Welsh health records with data from multiple, independent COVID-19 vaccine studies. These linkable datasets were made available for safe use within SAIL for approved study researchers. These results were combined with those from other Trusted Research Environments (TRE’s) across the four nations to perform UK-wide analyses.

Professor Ronan Lyons, Co-director of the SAIL Databank, said, “These large-scale studies of entire populations are tremendously helpful in conducting research to guide the scientific management of epidemics and other threats to health. We are enormously grateful to the population of Wales and the health and social care organisations who make their privacy-protected data available to undertake this vital research.”

The study, led by Health Data Research UK (HDR UK) and the University of Edinburgh, relied on secure access to anonymised health data for everyone in all four nations of the UK, an advance that has only become possible during the pandemic. The researchers say that this approach could be extended to many other areas of medicine with great potential for new discoveries in the understanding and treatment of disease.

Professor Sir Aziz Sheikh, Director of the Usher Institute at the University of Edinburgh, and study co-lead, said, “Large-scale data studies have been critical to pandemic management, allowing scientists to make policy-relevant findings at speed. COVID-19 vaccines save lives. As new variants emerge, this study will help to pinpoint groups of our society and areas of the country where public health campaigns should be focused and tailored for those communities.”

Early COVID-19 vaccine rollout began strongly in the UK, with over 90% of the population over the age of 12 vaccinated with at least one dose by January 2022. However, rates of subsequent booster doses across the UK were not known until now.

Scientists from England, Scotland, Northern Ireland and Wales studied securely held, routinely collected NHS data from everyone over 5 years of age during June 1 to September 30 2022.

Data from across the four countries was then pooled and harmonised – or made more uniform – a feat that was not possible until now. People were grouped by vaccine status, with under-vaccination defined as not having had all doses of a vaccine for which a person was eligible.

The findings reveal:

  • The proportion of under-vaccinated people on June 1st 2022 ranged between one-third and one-half of the population – 45.8% for England, 49.8% for Northern Ireland, 34.2% for Scotland and 32.8% Wales.
  • Modelling suggests 7,180 hospitalisations and deaths out of around 40,400 severe COVID-19 outcomes in summer 2022 might have been averted
  • Under-vaccination led to more hospitalisations and deaths across all age groups studied – those over 75 were more than twice as likely to have a severe COVID-19 outcome than those who were fully protected.
  • The highest rates of under-vaccination were found in younger people, men, people in areas of higher deprivation, and people of non-white ethnicity.

Researchers say the study – the largest ever carried out in the UK – also ushers in a new era for UK science by overcoming challenges in uniting NHS data that is gathered and stored in different ways between devolved nations.

Professor Cathie Sudlow, Chief Scientist at Health Data Research UK and Director of the British Heart Foundation (BHF) Data Science Centre, said, “The infrastructure now exists to make full use of the potential of routinely collected data in the NHS across the four nations of the UK. We believe that we could and should extend these approaches to many other areas of medicine, such as cancer, heart disease and diabetes to search for better understanding, prevention and treatment of disease.”

The study – named COALESCE – was set up to provide UK and devolved governments with data-driven insights into COVID-19 vaccination coverage and establish data pooling methods and infrastructure to pave the way for future UK-wide studies. It is led by HDR UK and the University of Edinburgh, in collaboration with research teams from across the four nations.

Read the full publication here in The Lancet

Infographics of study analysis and results. See also, a plain English summary here.