ABSTRACT
BACKGROUND: We sought to evaluate whether race/ethnicity disparities in severe COVID-19 outcomes persist in the era of vaccination. METHODS: Population-based age-adjusted monthly rate ratios (RR) of laboratory-confirmed COVID-19-asssociated hospitalizations were calculated among adult patients from COVID-19-Associated Hospitalization Surveillance Network (COVID-NET) during March 2020 - August 2022, by race/ethnicity. Among randomly sampled patients, July 2021-August 2022, RRs for hospitalization, intensive care unit (ICU) admission, and in-hospital mortality were calculated for Hispanic, Black, American Indian/Alaskan Native (AI/AN), and Asian/Pacific Islander (API) versus White persons. RESULTS: Based on data from 353,807 hospitalized patients, hospitalization rates were higher among Hispanic, Black and AI/AN versus White persons during March 2020 - August 2022, yet the magnitude of the disparities declined over time (for Hispanic, RR=6.7; 95%CI: 6.5-7.1 in June 2020 vs RR<2.0 after July 2021; for AI/AN, RR=8.4; 95%CI: 8.2-8.7in May 2020 vs RR<2.0 after March 2022; and for Black persons RR=5.3; 95%CI: 4.6-4.9 in July 2020 vs RR<2.0 after February 2022; all p≤0.001). Among 8,706 sampled patients during July 2021 - August 2022, hospitalization and ICU admission RRs were higher for Hispanic, Black, and AI/AN (range for both hospitalization and ICU admission: 1.4-2.4) and lower for API (range for both: 0.6-0.9) versus White persons. All other race and ethnicity groups had higher in-hospital mortality rates versus White persons (RR range: 1.4-2.9). CONCLUSIONS: Race/ethnicity disparities in COVID-19-associated hospitalizations declined but persist in the era of vaccination. Developing strategies to ensure equitable access to vaccination and treatment remains important.
ABSTRACT
BACKGROUND: Data assessing protection conferred from COVID-19 mRNA vaccination and/or prior SARS-CoV-2 infection during Delta and Omicron predominance periods in the United States are limited. METHODS: This cohort study included persons ≥18 years who had ≥1 health care encounter across 4 health systems and had been tested for SARS-CoV-2 before 26 August 2021. COVID-19 mRNA vaccination and prior SARS-CoV-2 infection defined the exposure. Cox regression estimated hazard ratios (HRs) for the Delta and Omicron periods; protection was calculated as (1-HR)×100%. RESULTS: Compared to unvaccinated and previously uninfected persons, during Delta predominance, protection against COVID-19-associated hospitalizations was high for those 2- or 3-dose vaccinated and previously infected, 3-dose vaccinated alone, and prior infection alone (range, 91%-97%, with overlapping 95% confidence intervals [CIs]); during Omicron predominance, estimates were lower (range, 77%-90%). Protection against COVID-19-associated emergency department/urgent care (ED/UC) encounters during Delta predominance was high for those exposure groups (range, 86%-93%); during Omicron predominance, protection remained high for those 3-dose vaccinated with or without a prior infection (76%; 95% CI = 67%-83% and 71%; 95% CI = 67%-73%, respectively). CONCLUSIONS: COVID-19 mRNA vaccination and/or prior SARS-CoV-2 infection provided protection against COVID-19-associated hospitalizations and ED/UC encounters regardless of variant. Staying up-to-date with COVID-19 vaccination still provides protection against severe COVID-19 disease, regardless of prior infection.