Over 10% of COVID Hospitalizations Involve Immunocompromised People

Immunocompromised individuals made up 12.2% of all COVID-related hospitalizations, despite accounting for only about 3% of the U.S. population, a CDC report showed.

And once hospitalized, there was no difference in the risk for death between vaccinated and unvaccinated immunocompromised patients, reported Jason Robert Singson, MPH, of the California Emerging Infections Program in Oakland, and colleagues in the Morbidity and Mortality Weekly Report.

Among vaccinated adults, those who were immunocompromised had higher odds of intensive care unit (ICU) admission (adjusted odds ratio [aOR] 1.40, 95% CI 1.01-1.92) and in-hospital death (aOR 1.87, 95% CI 1.28-2.75) compared with non-immunocompromised patients.

Immunocompromised patients who were not vaccinated also had higher odds of both ICU admission (aOR 1.26, 95% CI 1.08-1.49) and in-hospital death (aOR 1.34, 95% CI 1.05-1.70) compared with unvaccinated non-immunocompromised patients, the authors noted.

"The generally consistent association of individual immunocompromising conditions with increased odds of death suggests that immunocompromise itself was likely associated with severe outcomes," wrote Singson and colleagues.

In-hospital death varied depending on specific immunocompromising condition, with higher odds for those with multiple myeloma (aOR 5.28), solid organ transplant (aOR 2.12), AIDS or low CD4+ count (aOR 2.03), and immunosuppressive therapy use (aOR 1.65). Those with immunoglobulin deficiency had lower odds of in-hospital death (aOR 0.16).

COVID-19 variants also appeared to play a role in odds of ICU admission and in-hospital death. During the pre-Delta and Delta-predominant periods, immunocompromised patients had higher odds of death, regardless of vaccination status. During the Omicron-predominant period, there was no statistically significant difference between immunocompromised and non-immunocompromised individuals, regardless of vaccination status.

"Given the increased odds of severe COVID-19 outcomes among immunocompromised hospitalized patients, multilayered prevention strategies for immunocompromised persons are critical to preventing hospitalization for COVID-19 and subsequent severe outcomes, especially when community levels indicate increased transmission and disease severity," Singson and team noted.

"These strategies include implementing nonpharmaceutical interventions; ensuring that immunocompromised persons and their close contacts are up to date with COVID-19 vaccination; urging immunocompromised persons to use effective pre-exposure prophylactic therapeutics, such as Evusheld [tixagevimab and cilgavimab]; early testing, such as at-home tests; and early disease treatments, such as antiviral medications," they continued. "Improved access to and use of these measures with considerations for socioeconomically disadvantaged and historically underserved racial and ethnic groups will help ensure health equity."

For this report, data were taken from 10 states (California, Colorado, Connecticut, Georgia, Michigan, Minnesota, New Mexico, New York, Oregon, and Tennessee) in the COVID-19-Associated Hospitalization Surveillance Network (COVID-NET) from March 2021 through February 2022.

Of the 22,345 adults admitted to the hospital for COVID-19 during this time period, 2,209 were immunocompromised (354 vaccinated and 1,855 unvaccinated). Vaccination status was defined as having completed both doses of a two-dose series, or one dose of a single-dose vaccine, with or without additional or booster doses ≥14 days before a positive test result, per state immunization information system records.

Among the immunocompromised group, 37% had a solid tumor malignancy, 32% were on immunosuppressive therapies, 14% were solid transplant recipients, 6.7% had HIV, 2.7% had multiple myeloma, and 1.3% had AIDS or a low CD4+ count.

Analyses did not control for time since vaccination; since immunocompromised patients were eligible for vaccination before those who are not immunocompromised, earlier waning immunity was likely among this group.

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