Extended Data Fig. 5. Impact of prevalence of extant variant of concern (I_0,WT) at the time of new variant introduction.

For each Ag-RDT availability (differently colored), the expected day (points and line) and the standard deviation (shaded region) when the first Omicron variant specimen (in the background of Delta) is sampled for sequencing since its introduction is plotted against the proportion of positive specimens to be sampled for sequencing daily. Each panel shows a different prevalence of the Delta variant (I_0,WT) at the point of Omicron introduction. Sampling for sequencing was drawn from the population-wide scenario. The plotted results were computed from 1,000 random independent simulations for each surveillance strategy.