Hospitalization and Mortality Rates in US Veterans with COVID-19 During XBB, JN.1, KP Variants

Overview

This study analyzed 130,263 US Veterans infected with SARS-CoV-2 during the XBB, JN.1, and KP variant periods from September 2023 to October 2024. Hospitalization odds decreased significantly during the JN.1 and KP eras compared to the XBB era, while in-hospital mortality rates remained consistently low across all variant periods.

Background

SARS-CoV-2 has continued to evolve, with the XBB, JN.1, and KP variants predominating sequentially between September 2023 and October 2024. Although hospitalization and death risks from COVID-19 have declined since the pandemic began, these risks had not been evaluated during these newer variant periods. Understanding variant-specific risks is critical for guiding clinical management and public health strategies, especially in vulnerable populations such as US Veterans. This study leverages the Department of Veterans Affairs national database to assess hospitalization and mortality outcomes associated with these variants.

Data Highlights

Key Findings

• A total of 130,263 Veterans tested positive for SARS-CoV-2 during the study period.
• Overall hospitalization rate for COVID-19 was 2.07% (2,690 patients).
• In-hospital mortality was very low at 0.03% (38 patients) across all variant periods.
• Hospitalization odds were significantly lower during the JN.1 (OR 0.81) and KP (OR 0.80) variant eras compared to the XBB era.
• Patient characteristics associated with hospitalization and mortality included older age, higher area deprivation index, and greater healthcare utilization.
• Findings were robust across multiple sensitivity analyses including regional variant predominance and exclusion of coinfections.

Clinical Implications

Clinicians can anticipate a lower risk of hospitalization for COVID-19 among Veterans infected during the JN.1 and KP variant periods compared to the earlier XBB period, while mortality risk remains low. These data support continued vigilance but suggest improved clinical outcomes with newer variants in this population. Vaccination and comorbidity management remain important given patient risk profiles.

Conclusion

Among US Veterans infected with SARS-CoV-2 from September 2023 to October 2024, hospitalization risk declined during the JN.1 and KP variant periods compared to XBB, with consistently low in-hospital mortality across all periods. These findings provide important epidemiologic insights into evolving COVID-19 variant impacts in a high-risk population.

References

1. CDC COVID Data Tracker -- SARS-CoV-2 Variant Proportions Laboratory Surveillance
2. US Department of Veterans Affairs Study 2024 -- Hospitalization and Mortality Rates Associated with COVID-19 in US Veterans