Correction and Republication: Early Estimates of Bivalent mRNA Vaccine Effectiveness in Preventing COVID-19-Associated Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompetent Adults - VISION Network, Nine States, September-November 2022

Vaccine effectiveness against hospitalisation estimated using a test-negative case-control study design, and comparative odds of hospital admission and severe outcomes with COVID-19 sub-lineages BQ.1, CH.1.1. and XBB.1.5 in England

Background

Since the first emergence of Omicron BA.1 in England in November 2021, numerous sub-lineages have evolved. In September 2022, BA.5 dominated. The prevalence of BQ.1 increased from October, while the prevalence of CH.1.1 and XBB.1.5 increased from December 2022 and January 2023, respectively. Little is known about the effectiveness of the vaccines against hospitalisation with these sub-lineages, nor the relative severity, so we here used national-level electronic health records from England to estimate vaccine effectiveness and variant severity.

Methods

The study period for tests contributing to all analyses was from 5th December 2022 to 2nd April 2023, when the variants of interest were co-circulating. A test-negative case-control study was used to estimate the incremental effectiveness of the bivalent BA.1 booster vaccines against hospitalisation, relative to those with waned immunity where the last dose was at least 6 months prior. The odds of hospital admission for those testing PCR positive on the day of an attendance to accident and emergency departments and the odds of intensive care unit admission or death amongst COVID-19 admissions were compared between variants. Additionally, a Cox proportional hazards survival regression was used to investigate length of stay amongst hospitalised cases by variant.

Findings

Our vaccine effectiveness study included 191,229 eligible tests with 1647 BQ.1 cases, 877 CH.1.1 cases, 1357 XBB.1.5 cases and 187,348 test negative controls. There was no difference in incremental vaccine effectiveness against hospitalisation with BQ.1, CH.1.1 or XBB.1.5, nor was there a difference in the severity of these variants. Effectiveness against hospitalisation was 48.0% (95% C.I.; 38.5-56.0%), 29.7% (95% C.I.; 7.5-46.6%) and 52.7% (95% C.I.; 24.6-70.4%) against BQ.1, CH.1.1 and XBB.1.5, respectively, at 5-9 weeks post booster vaccination. Compared to BQ.1, the odds of hospital admission were 0.87 (95% C.I.; 0.77-0.99) and 0.88 (95% C.I.; 0.75-1.02) for CH.1.1 and XBB.1.5 cases attending accident and emergency departments, respectively. There was no significant difference in the odds of admission to intensive care units or death for those with CH.1.1 (OR 0.96, 95% C.I.; 0.71-1.30) or XBB.1.5 (OR 0.67, 95% C.I.; 0.44-1.02) compared to BQ.1. There was also no significant difference in the length of hospital stay by variant.

Interpretation

Together, these results provide reassuring evidence that the bivalent BA.1 booster vaccines provide similar protection against hospitalisation with BQ.1, CH.1.1 and XBB.1.5, and that the emergent CH.1.1 and XBB.1.5 sub-lineages do not cause more severe disease than BQ.1.

Funding

None.

Managing hospitalized patients with COVID-19

ABSTRACT

Treatment for COVID-19 has significantly changed since the beginning of the pandemic and continues to change as new evidence is published. This article describes which COVID-19 patients require hospitalization and how to manage hospitalized patients based on current evidence from randomized clinical trials.

Bolstering the Measurement of Racial Inequity of COVID-19 Vaccine Uptake

Inequities in COVID-19 vaccine uptake by racialized groups have been persistent throughout the vaccine rollout, leading to disparate burdens of COVID-19 outcomes. A cross-sectional study was conducted to determine COVID-19 vaccine uptake across racialized groups within the nine-county Finger Lakes region of New York State in December 2021. Cross-matching and validation were performed across multiple health information systems for the region to reduce the percentage of vaccine records with missing race information. Additionally, imputation techniques were applied to address the remaining missing values. Uptake of ≥1 dose of the COVID-19 vaccine by race was then examined. By December 2021, 828,551 individuals in our study region had received ≥1 dose of the COVID-19 vaccine, with ~25% having missing race values. Cross-matching and validation within existing records reduced this to ~7%. Uptake of ≥1 dose of a COVID-19 vaccine was greatest among individuals identifying as White, followed by those identifying as Black. The application of imputation techniques reduced the percent of missing race values to <1%; however, this reduction did not significantly change the distribution of vaccine uptake across race groups. Utilization of relevant health information systems, accompanied by imputation techniques, stands to greatly reduce the burden of missing race data within vaccine registries, facilitating accurate targeted interventions to mitigate inequities in COVID-19 vaccination.