Abstract and Introduction
Introduction
Immunocompromised persons are at increased risk for severe COVID-19–related outcomes, including intensive care unit (ICU) admission and death.[1] Data on adults aged ≥18 years hospitalized with laboratory-confirmed COVID-19 from 10 U.S. states in the COVID-19–Associated Hospitalization Surveillance Network (COVID-NET) were analyzed to assess associations between immunocompromise and ICU admission and in-hospital death during March 1, 2020–February 28, 2022. Associations of COVID-19 vaccination status with ICU admission and in-hospital death were also examined during March 1, 2021–February 28, 2022. During March 1, 2020–February 28, 2022, among a sample of 22,345 adults hospitalized for COVID-19, 12.2% were immunocompromised. Among unvaccinated patients, those with immunocompromise had higher odds of ICU admission (adjusted odds ratio [aOR] = 1.26; 95% CI = 1.08–1.49) and in-hospital death (aOR = 1.34; 95% CI = 1.05–1.70) than did nonimmunocompromised patients. Among vaccinated patients,* those with immunocompromise had higher odds of ICU admission (aOR = 1.40; 95% CI = 1.01–1.92) and in-hospital death (aOR = 1.87; 95% CI = 1.28–2.75) than did nonimmunocompromised patients. During March 1, 2021–February 28, 2022, among nonimmunocompromised patients, patients who were vaccinated had lower odds of death (aOR = 0.58; 95% CI = 0.39–0.86) than did unvaccinated patients; among immunocompromised patients, odds of death between vaccinated and unvaccinated patients did not differ. Immunocompromised persons need additional protection from COVID-19 and using multiple known COVID-19 prevention strategies,† including nonpharmaceutical interventions, up-to-date vaccination of immunocompromised persons and their close contacts,§ early testing, and COVID-19 prophylactic (Evusheld) and early antiviral treatment,¶ can help prevent hospitalization and subsequent severe COVID-19 outcomes among immunocompromised persons.
COVID-NET is a CDC-funded collaboration for population-based surveillance of laboratory-confirmed COVID-19–associated hospitalization in 99 U.S. counties in 14 states. A COVID-NET case is defined as a positive real-time reverse transcription–polymerase chain reaction or rapid antigen test result for SARS-CoV-2 (the virus that causes COVID-19) within 14 days before or during hospitalization in a person who lived in the surveillance catchment area. Medical chart abstraction and representative sampling methods have been described previously.[2] Data collected on sampled adults hospitalized during March 1, 2020–February 28, 2022, across 10 participating states** were examined. Patients whose hospitalization was not likely related to COVID-19†† and those without a completed chart review were excluded. Immunocompromised patients were defined as those having one or more predefined immunocompromising conditions.§§ COVID-19 vaccination definitions for immunocompromised persons changed during the study period¶¶; in this analysis, a vaccinated patient was defined as one who had received both doses of a 2-dose COVID-19 vaccination series or 1 dose of a single-dose COVID-19 vaccine with or without additional or booster doses ≥14 days before their positive SARS-CoV-2 test result, per state immunization information system records. Vaccinated patients with additional or booster doses were not analyzed separately. Patients were considered unvaccinated if no COVID-19 vaccination was recorded before the positive test result; patients who were documented to have received only the first dose of a 2-dose series or their last vaccination series dose <14 days before receiving a positive SARS-CoV-2 test result were excluded.
Demographic and clinical characteristics of hospitalized patients were assessed; Pearson's chi-square tests were used to compare differences between immunocompromised and nonimmunocompromised patients. Bivariate and multivariable logistic regression analyses were used to assess associations between immunocompromise and both ICU admission and in-hospital death among vaccinated and unvaccinated patients in separate models. Associations between each individual immunocompromising condition and death were assessed using multivariable analyses, adjusting only for age and sex to improve model convergence. Bivariate and multivariable analyses were used to assess the association between vaccination status and both ICU admission and in-hospital death among immunocompromised and nonimmunocompromised patients in separate models, using data beginning March 1, 2021, when immunocompromised patients first reported receiving vaccine doses, through February 28, 2022. Multivariable analyses were adjusted for age, sex, site (entered as a fixed effect), SARS-CoV-2 variant–predominant period,*** and other factors with documented or potential association and a p-value <0.10 in bivariate analyses. Statistical analyses used SAS (version 9.4; SAS Institute) survey procedures to account for sampling weights, with statistical significance set at alpha = 0.05. This activity was reviewed by CDC and conducted consistent with applicable federal law and CDC policy.†††
During March 1, 2020–February 28, 2022, a representative sample of 24,625 (11.0%, unweighted) of 223,069 COVID-NET cases had complete chart review, including 22,345§§§ (90.7%, unweighted) that met inclusion criteria. Among the 22,345 patients included, 12.2% were immunocompromised, including 11.1%, 10.9%, and 17.3% of patients hospitalized during the pre-Delta, Delta, and Omicron variant–predominant periods, respectively. Overall, immunocompromised patients were more likely to be older and to be non-Hispanic White (Table 1). Compared with nonimmunocompromised patients, those with immunocompromise had a statistically significantly higher prevalence of all underlying medical conditions except diabetes and neurologic disease.
Among unvaccinated patients, those who were immunocompromised had higher odds of ICU admission (aOR = 1.26) and death (aOR = 1.34) than did nonimmunocompromised patients¶¶¶ (Table 2). Similarly, among vaccinated patients, those who were immunocompromised also had higher odds of ICU admission (aOR = 1.40) and in-hospital death (aOR = 1.87) compared with nonimmunocompromised patients.**** Among patients with a specific immunocompromising condition compared with patients without that condition (irrespective of immunocompromise status), the odds of in-hospital death were higher for those with AIDS or low CD4+ count (aOR = 2.03), immunosuppressive therapy use (aOR = 1.65), multiple myeloma (aOR = 5.28), or solid organ transplant (aOR = 2.12) and lower for patients with immunoglobulin deficiency (aOR = 0.16) (Supplementary Table 1, https://stacks.cdc.gov/view/cdc/118606).
Among immunocompromised patients, those who were vaccinated did not have statistically significantly different odds of ICU admission or in-hospital death†††† compared with unvaccinated patients (Table 3). Among nonimmunocompromised patients, those who were vaccinated had lower odds of death (aOR = 0.58) than did unvaccinated patients.§§§§
During the pre-Delta and Delta variant–predominant periods, immunocompromised patients generally had higher odds of death, irrespective of vaccination status compared with nonimmunocompromised patients, and nonimmunocompromised patients who were vaccinated had lower odds of death compared with unvaccinated patients (Supplementary Table 2, https://stacks.cdc.gov/view/cdc/118607). However, in the Omicron variant–predominant period, odds of death, irrespective of immunocompromise or vaccination status, were not statistically significantly different.
Morbidity and Mortality Weekly Report. 2022;71(27):878-884. © 2022 Centers for Disease Control and Prevention (CDC)
