Omicron Positivity in Air of Hospital Settings Gathered COVID-19 Patients, Vaccinated/Unvaccinated Populations

The Omicron variant spreads quicker than the earlier variants and can evade immune response. behavior changes waning immunity could cause large numbers of COVID-19 infections potential hospitalizations. Here, we present a cross-sectional/longitudinal study conducted in tertiary hospital Istanbul. In cross-sectional part, collected aerosol samples from clinical public areas hospital. We performed qPCR viral culture. pediatrics, outpatient clinic waiting room, where children were without masks, unvaccinated, 66% positive for RNA. However, positivity rate was 14% staff dining hall everybody masks but fully vaccinated. RNA 50% patient rooms, 33% febrile disease clinic, laboratory room. There no growth culture all samples. highest load detected room (3.60×1010 PFU m-3), followed by pediatrics (2.8×108 m-3). longitudinal study, 0, 2.5, 4.5, 24 hours after meeting which attendees wearing three participants diagnosed with COVID-19. Only one sample weakly (1.12×102 conclusion, mask use vaccination are still main effective methods preventing indoor environments. Unvaccinated significant source air contamination risk further transmission