Fig. 1: Kaplan–Meier survival curve of time to symptom end date in those self-reporting symptomatic SARS-CoV-2 infection, overall and by dominant variant at the time of infection.

The curve shows the probability that a participant continues to have symptoms beyond time t. Participants infected at a time when Wild-type (blue) was dominant had a higher probability of symptoms continuing beyond time t compared to Alpha (red), Delta (grey) and Omicron (orange). The number at risk table below the curve shows, overall and by dominant variant at the time of infection, the number at risk at any specific time point. This is equal to the total number of participants remaining in the study including any individuals who experience the event of interest (symptom end date) or participants who are censored at this time point. The unit of time is “weeks,” so the number at risk is those participants who have not yet experienced the event of interest or been censored at the beginning of the week (before any event or censoring could occur). The number of participants who recovered within the previous time window are shown below the number at risk table. This is equal to the total number of participants with a symptom end date within the time window ending at this time point.