Inflammatory Biomarkers Differ among Hospitalized Veterans Infected with Alpha, Delta, and Omicron SARS-CoV-2...

Area of Science:

• Infectious Diseases
• Immunology
• Public Health

Background:

• COVID-19 mortality is linked to inflammatory markers like C-reactive protein (CRP).
• The Omicron variant's lower mortality compared to Alpha and Delta may stem from variant-specific immunity or host factors like vaccination.
• Previous research suggests a correlation between COVID-19 variants and disease severity.

Purpose of the Study:

• To investigate if the Omicron variant causes less inflammation than Alpha and Delta variants.
• To compare inflammatory markers and in-hospital mortality between COVID-19 variants in a veteran population.
• To determine the impact of vaccination status on these comparisons.

Main Methods:

• Retrospective cohort study of hospitalized COVID-19 veterans at the Veterans Health Administration.
• Comparison of inflammatory markers (CRP, Ferritin, AST, ALT, LDH, Albumin) and mortality across Alpha, Delta, and Omicron variant infections.
• Analysis stratified by vaccination status.

Main Results:

• Omicron infections showed significantly lower odds of abnormal C-reactive protein (CRP) compared to Alpha and Delta variants.
• Inflammatory markers including Ferritin, Alanine aminotransferase, Aspartate aminotransferase, Lactate dehydrogenase, and Albumin were also lower in Omicron cases.
• In-hospital mortality was significantly lower for Omicron variant infections compared to Alpha and Delta, irrespective of vaccination status.

Conclusions:

• The Omicron variant is associated with milder inflammatory responses and reduced mortality compared to the Alpha and Delta variants.
• These findings suggest a variant-specific effect on disease severity, independent of host vaccination status.
• The study highlights the importance of considering viral variants when assessing COVID-19 outcomes.