Hospital outbreak of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) delta variant in partially and fully vaccinated patients and healthcare workers in Toronto, Canada.

The severe acute respiratory coronavirus virus 2 (SARS-CoV-2) delta variant is highly transmissible, and current vaccines may have reduced effectiveness in preventing symptomatic infection. Using epidemiological and genomic analyses, we investigated an outbreak of the variant in an acute-care setting among partially and fully vaccinated individuals. Effective outbreak control was achieved using standard measures.