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Published on: November 10, 2023
Impact of COVID-19 on immunocompromised populations during the Omicron era: insights from the observational
Rachael A Evans1, Sabada Dube2, Yi Lu3
1Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom.
Insights
Immunocompromised individuals face a higher risk of severe COVID-19 outcomes, including hospitalizations and deaths, even after vaccination. Targeted preventive strategies are urgently needed for these vulnerable populations.
Area of Science:
- Immunology
- Infectious Diseases
- Public Health
Background:
- COVID-19 vaccines offer suboptimal protection for immunocompromised individuals.
- Assessing severe COVID-19 risk in immunocompromised groups is crucial as the pandemic transitions to an endemic phase.
Purpose of the Study:
- To characterize and describe the risk of severe COVID-19 outcomes among various immunocompromised groups.
- To identify specific immunocompromised populations at highest risk for severe COVID-19.
Main Methods:
- Retrospective cohort study using electronic health data from a 25% sample of the English population (≥12 years).
- Comparison of COVID-19 hospitalizations, ICU admissions, and deaths between 2022 in immunocompromised individuals versus the general population.
- Analysis included individuals with ≥3 COVID-19 vaccine doses.
Main Results:
- Immunocompromised individuals represented 3.9% of the population but 22-28% of severe COVID-19 outcomes in 2022.
- Even with ≥3 vaccine doses, immunocompromised groups showed increased risk (aIRR 1.3–13.1 for hospitalization).
- Highest hospitalization risks were observed in solid organ transplant recipients, those with primary immunodeficiency, stem cell transplant recipients, and those recently treated for hematological malignancy.
Conclusions:
- Immunocompromised individuals remain disproportionately affected by COVID-19, necessitating additional preventive measures beyond vaccination.
- Findings can guide the development of targeted prevention strategies for high-risk immunocompromised groups.
Background:
Immunocompromised individuals are not optimally protected by COVID-19 vaccines and potentially require additional preventive interventions to mitigate the risk of severe COVID-19. We aimed to characterise and describe the risk of severe COVID-19 across immunocompromised groups as the pandemic began to transition to an endemic phase.
Methods:
COVID-19-related hospitalisations, intensive care unit (ICU) admissions, and deaths (01/01/2022-31/12/2022) were compared among different groups of immunocompromised individuals vs the general population, using a retrospective cohort design and electronic health data from a random 25% sample of the English population aged ≥12 years (Registration number: ISRCTN53375662).
Findings:
Overall, immunocompromised individuals accounted for 3.9% of the study population, but 22% (4585/20,910) of COVID-19 hospitalisations, 28% (125/440) of COVID-19 ICU admissions, and 24% (1145/4810) of COVID-19 deaths in 2022. Restricting to those vaccinated with ≥3 doses of COVID-19 vaccine (∼84% of immunocompromised and 51% of the general population), all immunocompromised groups remained at increased risk of severe COVID-19 outcomes, with adjusted incidence rate ratios (aIRR) for hospitalisation ranging from 1.3 to 13.1. At highest risk for COVID-19 hospitalisation were individuals with: solid organ transplant (aIRR 13.1, 95% confidence interval [95% CI] 11.2-15.3), moderate to severe primary immunodeficiency (aIRR 9.7, 95% CI 6.3-14.9), stem cell transplant (aIRR 11.0, 95% CI 6.8-17.6), and recent treatment for haematological malignancy (aIRR 10.6, 95% CI 9.5-11.9). Results were similar for COVID-19 ICU admissions and deaths.
Interpretation:
Immunocompromised individuals continue to be impacted disproportionately by COVID-19 and have an urgent need for additional preventive measures beyond current vaccination programmes. These data can help determine the immunocompromised groups for which targeted prevention strategies may have the highest impact.
Funding:
This study was funded by AstraZeneca UK.
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