Fig. 1

Declining viral loads after symptom onset. a Data from all 17 studies used in our analysis (circles). For illustrative purposes, viral samples that were negative for the virus are set to 1 viral copy per ml. The median viral load is calculated for each day (purple line), as well as the interquartile range (purple shaded region). From day 20 onwards, over half the samples recorded on each of these days were below the limit of detection. b Here we show the quantified PCR data (yellow) separately from the data for which viral loads were estimated (blue) using an averaged standard curve (Materials and methods). In the lower panels (c, d), we display the number of data points available on each day for this analysis