Immunocompromised individuals remain at risk of COVID-19: 2023 results from the observational INFORM study

Abstract

Objectives

We aimed to characterise coronavirus disease 2019 (COVID-19) severity, mortality and healthcare utilisation in immunocompromised individuals in England during 2023, using INFORM (INvestigation oF cOvid-19 Risk among iMmunocompromised populations) study data.

Methods

Retrospective cohort study (ISRCTN53375662) using pseudonymised electronic health records of individuals aged ≥12 years from a random 25% sample of England’s population. Over 1 January–31 December 2023, adjusted incidence rate ratios (aIRRs; adjusted for age, sex, non-immunocompromising comorbidities) between immunocompromised and non-immunocompromised individuals for COVID-19-related hospitalisation, death, and healthcare utilisation were estimated.

Results

Immunocompromised individuals represented 4.0% of 12,056,685 individuals studied but accounted for 21.7% and 21.9% of COVID-19 hospitalisations and deaths, respectively. Risk of severe COVID-19 was elevated for immunocompromised vs. non-immunocompromised; aIRRs: 2.04, 95% CI 1.95–2.14 (COVID-19 hospitalisation); 1.69, 95% CI 1.53–1.87 (COVID-19 death). COVID-19 vaccination was more likely in immunocompromised vs. non-immunocompromised (≥4 doses 72.6% vs. 29.8%). The aIRRs for COVID-19-related general practitioner consultations and accident and emergency/day case visits were 2.26 (95% CI 2.22−2.29) and 3.02 (95% CI 2.84−3.20), respectively, for immunocompromised vs. non-immunocompromised.

Conclusions

Beyond three years since the start of the COVID-19 pandemic, immunocompromised individuals remain disproportionately impacted from COVID-19 despite increased vaccination. These findings highlight a persistent need for additional COVID-19 interventions for immunocompromised populations.