Lack of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) transmission from a healthcare worker to a cohort of immunosuppressed patients during the SARS-CoV-2 omicron variant surge, California, 2022

Infection of healthcare workers despite a high vaccination rate during the fifth wave of COVID-19 due to Omicron variant in Hong Kong

“…Recent studies showed that the universal use of surgical respirators as an additional infection preventive measure contributed to the rapid control of Omicron transmission in the hospital [ 42 ]. Use of the surgical respirator by an infected HCW may be one of the reasons for the lack of Omicron transmission in a cohort of immunosuppressed patients [ 43 ]. These preliminary findings may provide indirect epidemiological evidence of airborne transmission of the Omicron variant in the clinical areas.…”