More than 7,000 COVID-19 deaths and hospitalizations in the United Kingdom could have been averted in summer 2022 if the population had received the recommended number of vaccine doses, suggests a meta-analysis published yesterday in The Lancet.
Researchers from the Health Data Research (HDR) UK COALESCE Consortium and the University of Edinburgh analyzed the electronic health records of 67 million UK residents aged 5 and older to identify the factors and risks tied to undervaccination from June to September 2022.
In the United Kingdom at that time, the recommended vaccine schedule was one dose for those aged 5 to 11 years, two doses for those 12 to 15 years, three doses for 16 to 74 years, and four for those 75 years and older.
"In the UK, uptake of the first vaccine dose was high; by January, 2022, more than 90% of the UK population older than 12 years had received a COVID-19 vaccine," the study authors wrote. "However, as more doses have been offered, uptake has declined."
Elderly at nearly triple the risk for severe outcomes
A total of 45.8% of about 59 million people in England, 49.8% of 1.9 million in Northern Ireland, 34.2% of 5 million in Scotland, and 32.8% of 2.4 million in Wales were undervaccinated.
Risk factors for undervaccination were younger age, socioeconomic deprivation, non-White ethnicity, and fewer underlying illnesses. Of the 40,393 poor COVID-19 outcomes, 14,156 were among undervaccinated participants.
In total, 33,885 COVID-19 patients died or were hospitalized during the study period. The estimated reduction in death or hospitalization over 4 months of follow-up had everyone been fully vaccinated as of June 1, 2022, was 210 in those aged 5 to 15 years, 1,544 in those 16 to 74, and 5,426 in those 75 years or older, for a total of 7,180.
"Our analysis indicates that higher vaccination coverage would have been associated with considerable reduction in severe COVID-19 outcomes, particularly among at-risk subpopulations in the UK," the researchers wrote.
Adjusted hazard ratios (aHRs) for death or hospitalization for participants aged 16 to 74 years were 1.26 for a vaccine deficit of one dose, 1.88 for two missed doses, and 1.50 for three missed doses. The aHRs among those aged 75 years or older were 2.70 for one missing dose, 3.13 for two missed doses, 3.61 for three, and 3.08 for four.
Our analysis indicates that higher vaccination coverage would have been associated with considerable reduction in severe COVID-19 outcomes, particularly among at-risk subpopulations in the UK.
"COVID-19 vaccines save lives," study co-lead author and HDR UK Research Director Aziz Sheikh, MBBS, MD, of the University of Edinburgh, said in a consortium news release. "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."
Boosting capacity, motivation for full vaccination
In a related commentary, Martin Gulliford, MD, and Claire Stevens, MSc, both of King's College London, noted that missing just one COVID-19 vaccine dose in those aged 75 and older had close to the same link with poor outcomes as missing all four doses recommended for that age-group. "This is likely to be accounted for by a known decline in vaccine-induced immunity over time," they wrote.
Increasing COVID-19 coverage in socioeconomically deprived area will require continued efforts by vaccination-program providers to reach people eligible for vaccines to boost capacity, opportunity, and motivation for receiving all recommended doses.
"Although dissemination of key messages from Kerr and colleagues through social media might be particularly relevant in communities where these media provide important sources of information to shape attitudes and behaviours, the study found that the greatest benefit will be achieved in addressing deprived populations over the age of 75 years, for whom misinformation might be less salient," they concluded.
