Optimized Post-Vaccination Strategies and Preventative Measures for SARS-CoV-2

Area of Science:

• Epidemiology
• Infectious Disease Modeling
• Public Health Policy

Background:

• The COVID-19 pandemic necessitated widespread non-pharmaceutical interventions (NPIs) and vaccination campaigns.
• The emergence of variants like Delta highlighted the need for adaptable strategies.
• Site-specific data is crucial for justifying the relaxation or intensification of COVID-19 preventative measures in workplaces.

Approach:

• A simulation model was developed to assess SARS-CoV-2 transmission in a workplace setting.
• The model incorporated variables such as community infection rates (CIR), vaccination status and efficacy, NPIs, and testing strategies.
• 33,462 unique workplace scenarios were simulated to estimate infection counts.

Key Points:

• Low CIR (≤5/100,000) and 50% vaccination (95% efficacy) allow daily antigen or PCR testing of unvaccinated workers with <1 infection per 4,800 person-weeks.
• At CIR ≤60/100,000 and 100% vaccination (95% efficacy), no masking or routine testing/isolation is needed, irrespective of variant.
• Antigen-based testing and isolation yield similar or fewer workplace infections compared to PCR methods.

Conclusions:

• Specific workplace scenarios permit the safe relaxation of masking and testing/isolation strategies.
• Targeted testing and quarantine for unvaccinated cohorts are effective.
• Antigen testing offers advantages over PCR due to faster turnaround times, despite lower sensitivity.