Fig. 2.

(A, B) Fluctuations in the titer of influenza A virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surviving on the surface of PP, IP, and IPP. For each measurement, four independent experiments were performed, and the results are expressed as mean ± standard error. (C, D) Stability of IAV and SARS-CoV-2 on the surface of PP, IP, and IPP. Data were analyzed using GraphPad Prism 7 software (GraphPad, Inc., La Jolla, CA, USA). The elapsed time was defined as an explanatory variable (X-axis), and the log virus titer of IAV or SARS-CoV-2 was defined as an explained variable (Y-axis); least-squares linear regression analysis with a logarithmic link function was performed for each virus, to generate a curve of regression. The upper and lower confidence limits are represented by dotted curves. The black dotted straight lines represent the detection limit titers of IAV and SARS-CoV-2. The black dotted straight lines represent the detection limit titers of IAV and SARS-CoV-2.