Figure : Proportion of HCWs testing positive for SARS-CoV-2 in the CUHNHFT asymptomatic screening programme (grey bars; week 1, 18/01/2021-24/01/2021; week 2, 25/01/2021-31/01/2021) and Ct values of positive tests (CT<36; blue dots; both weeks). RT-PCR targeting the SARS-CoV-2 ORF1ab genes was conducted at the Cambridge COVID-19 Testing Centre (part of the UK Lighthouse Labs Network). For proportions testing positive, p values for pair-wise comparisons of unvaccinated HCWs with HCWs <12 days or> 12 days post-vaccination are shown (Fisher’s exact test; both weeks). For Ct values, medians ± interquartile ranges are shown.