Simulating COVID-19 classroom transmission on a university campus

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Modeling

Background:

• Assessing airborne transmission risk of SARS-CoV-2 in university settings is critical for safe operations.
• Understanding the impact of variants and mitigation strategies like vaccination and mask-wearing is essential.

Purpose of the Study:

• To model and quantify airborne transmission risk of SARS-CoV-2 in university classrooms.
• To evaluate the effectiveness of reduced in-person classes, mask usage, and vaccination on mitigating transmission.
• To determine vaccination thresholds for safe full occupancy under different scenarios.

Main Methods:

• Developed an airborne transmission risk model for enclosed spaces, incorporating room characteristics, mask efficacy, and infection probability.
• Simulated transmission risk using university course registration data from pre-pandemic and hybrid instruction periods.
• Assessed the impact of varying levels of online classes, mask mandates, and vaccination rates.

Main Results:

• Shifting 90% of classes online reduced new cases by 17-18x without vaccination.
• Universal mask usage decreased classroom-related infections by 2.7-3.6x.
• For the original SARS-CoV-2 strain, 23% vaccination (with masks) or 64% (without masks) was needed for full occupancy; for a more contagious variant, 93% vaccination was required even with masks.

Conclusions:

• Hybrid learning models and universal masking are effective in reducing SARS-CoV-2 transmission in university settings.
• Vaccination is a critical component for enabling full campus occupancy, with higher rates required for more transmissible variants.
• The developed model accurately predicts observed infection trends, providing a valuable tool for university pandemic planning.