SARS-CoV-2 Omicron variant shedding during respiratory activities.

Area of Science:

• Virology
• Infectious Diseases
• Public Health

Background:

• The transition to COVID-19 endemicity necessitates understanding aerosol shedding of SARS-CoV-2 variants of concern (VOCs).
• Previous studies analyzed pre-Omicron variants, but Omicron's shedding patterns require further investigation for effective infection control.
• Seasonal circulation of VOCs demands updated public health strategies.

Purpose of the Study:

• To compare the aerosol shedding patterns of the Omicron VOC with pre-Omicron variants.
• To assess SARS-CoV-2 aerosol shedding during different respiratory activities.
• To inform infection control measures against currently circulating variants.

Main Methods:

• Aerosol samples (coarse and fine) were collected from 47 SARS-CoV-2 infected patients.
• Samples were analyzed during passive breathing, talking, and singing using RT-qPCR and virus culture.
• Comparison of shedding between Omicron and pre-Omicron variant infections.

Main Results:

• Comparable SARS-CoV-2 RNA copy numbers were found in aerosols of Omicron-infected patients versus pre-Omicron variants, irrespective of vaccination status.
• Omicron infections showed a slight increase in viral aerosol shedding during breathing.
• A higher likelihood of persistent aerosol shedding beyond 7 days post-onset was observed in Omicron cases.

Conclusions:

• Omicron exhibits distinct aerosol shedding characteristics compared to previous SARS-CoV-2 variants.
• Findings support continued layered public health interventions, even in highly vaccinated populations.
• Understanding variant-specific shedding is crucial for managing seasonal COVID-19 transmission.