Fig. 4: Fitted model results for RSV (green) and hMPV (orange) in Scotland from week of October 16, 2006, through week of March 4, 2024.

The model estimates the number of susceptible individuals (A, B), the number of infected individuals (C, D), and the number of detected infections (E, F). Model estimates of detections account for underreporting and variations in testing (see Supplementary Fig. 3). The model was fit to observed detections of RSV and hMPV (points in E, F) before week of June 16, 2018 (black vertical line) and simulated forward out of sample, using Google mobility data (gray) to determine the strength of NPIs during the pandemic perturbation. One hundred random samples from the posterior distribution are shown; one hundred random out of sample post-pandemic simulations from the independent model are also shown for reference (black). See Supplementary Fig. 5 and Supplementary Fig. 6, respectively, for results from a sensitivity analysis using an SIRS model and independent SEIRS model with no interaction between RSV and hMPV.