COVID-19 long-term sequelae: Omicron versus Alpha and Delta variants

Area of Science:

• Virology
• Infectious Diseases
• Public Health

Background:

• COVID-19, caused by SARS-CoV-2, can lead to persistent symptoms known as long COVID or post-COVID-19 syndrome.
• Different SARS-CoV-2 variants, including Alpha, Delta, and Omicron, have emerged with varying characteristics.
• Understanding the association between specific variants and the risk of long-term sequelae is crucial for patient management.

Purpose of the Study:

• To investigate the association between SARS-CoV-2 variants (Alpha, Delta, Omicron) and the risk of long COVID, post-COVID-19 syndrome, and viral persistence.
• To identify risk factors contributing to the development of long-term COVID-19 symptoms.
• To inform clinical management strategies for patients with varying COVID-19 variant infections.

Main Methods:

• Retrospective analysis of 325 hospitalized COVID-19 patients with available genomic sequencing data.
• Comparison of symptom frequency and long-term sequelae across different SARS-CoV-2 variants using statistical tests (Chi-squared, Fisher's exact, Kruskal-Wallis, Dunn's).
• Logistic regression models were employed to calculate odds ratios (OR) for risk factors and sequelae.

Main Results:

• The Omicron variant was associated with significantly lower odds of long COVID and post-COVID-19 syndrome compared to the Alpha variant (OR, 0.30).
• Indicators of severe illness, such as ICU admission (OR, 1.14) and treatment with antiviral or immunomodulatory drugs (OR, 2.01), predicted increased risk of long-term symptoms.
• No significant differences in viral persistence were observed between the studied variants.

Conclusions:

• The Omicron variant demonstrates a reduced risk for developing long-term COVID-19 sequelae compared to earlier variants.
• Severity of illness is a key predictor for long-term symptoms, independent of vaccination status, age, sex, or comorbidities.
• Findings have implications for healthcare management and outpatient follow-up; further research on non-hospitalized patients is warranted.