Fig. 2: Description of the Omicron positive swabs.
From: Dynamics of a national Omicron SARS-CoV-2 epidemic during January 2022 in England
Daily proportion of BA.2 (vs BA.1 or BA.1.1) infections among (n = 2393) positive swabs with determined lineage and at least 50% genome coverage in round 17 (A). Point estimates (means) are represented (dots) along with 95% confidence intervals (vertical lines). Smoothed estimates of the proportion are also shown (solid line) together with their 95% credible intervals (shaded regions). No sequencing data were available for January 21, 2022. Distribution of the Ct value for the N gene (B) and E gene (C) in swab-positive samples from round 15 (Delta), round 16 (predominantly Delta) and round 17 (predominantly Omicron). Within each round, distributions are compared (i) for vaccinated vs. unvaccinated participants aged 17 years and under, (ii) those having received three vs two vaccine doses in adults aged 18 to 54 years, and (iii) for those reporting any symptoms vs those not reporting any symptom in the month prior to swabbing. For each comparison, we report the P-value from a non-parametric (Kruskal-Wallis) test.
