Catalog · Physics of COVID-19 Transmission Lecture 35 of 49 Video 4-9: Safety Guideline for COVID-19—Role of Prevalence of Infection ← Previous Video 4-8: Safety Guideline for COVID-19—Case Studies Next → Video 4-10: Safety Guideline for COVID-19—Risk Scenarios ✓ Mark complete Materials Transcript (PDF) ↗ transcript