First all-UK study reveals consequences of missed COVID-19 vaccines


A new research study has found that 7,000 hospitalisations and deaths could have been averted in summer 2022 if the UK had had better COVID-19 vaccine coverage.

Gaps in COVID-19 vaccine coverage were highlighted in the COALESCE study, the first research study of the entire UK population, which found that COVID-19 vaccination levels are lower than might be expected for booster jabs.

With COVID-19 cases on the rise and a new variant strain recently identified, this research provides a timely insight into the consequences of vaccine hesitancy that could inform public health decisions by policymakers.

It also demonstrates the value of whole-population studies and how this approach could be used in future to address other diseases.

The University of Strathclyde was a partner in the study, which was led by Health Data Research UK (HDR UK) and the University of Edinburgh. The research has been published in The Lancet.

Professor Chris Robertson, of Strathclyde’s Department of Mathematics and Statistics and Public Health Scotland, who was statistical lead, said: “This study demonstrated that analyses of health data for the whole UK are possible. Careful and collaborative work by researchers and public health experts in four nations was needed to achieve this.

“The path is now open to replicating the analysis for other vaccines and other disease areas to fully utilise the health data in the UK and provide high quality evidence for policy makers.”

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

Scientists from England, Scotland, Northern Ireland and Wales studied securely-held, routinely collected NHS data from everyone over five years of age from 1 June to 30 September 2022. All data was de-identified and available only to approved researchers.

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 that a person was eligible.

The findings reveal that the proportion of people who were under-vaccinated on 1 June 2022 ranged between one third and one half of the population – 45.7% for England, 49.8% for Northern Ireland, 34.2% for Scotland and 32.8% Wales.

Mathematical modelling indicated that 7,180 hospitalisations and deaths out of around 40,400 severe COVID-19 outcomes during four months in summer 2022 might have been averted, if the UK population was fully vaccinated.

Under-vaccination was related to significantly more hospitalisations and deaths across all age groups studied, with under-vaccinated people over 75 more than twice as likely to have a severe COVID-19 outcome as 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.

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."