Among subjects with a positive RT-PCR result for influenza A at the first measurement and a self-swab available, 109 of 121 (90%) subjects in the IRIS had detectable virus in the selfcollected swab 2-5 days after illness onset. In the HTS with an HCP-collected swab, 132 of 183 (72%) subjects had detectable virus in the swab 2-7 days after illness onset. For influenza B, the corresponding statistics were 49 of 55 (89%) for the IRIS (2-5 days after onset) and 74 of 117 (63%) for the HTS (2-7 days after onset).