Estimate (95% CI) of R for all strains, the H3N2v-M variant, and variants other than H3N2v-M, for different scenarios of detection and overdispersion in the offspring distribution.

We consider three scenarios for the case-to-case variation in infectiousness: high (i.e., most transmission events are caused by a small proportion of cases like for SARS; k = 0.16), medium (k = 0.5), and low (k = 5) [12].an is the number of clusters. F is the proportion of first detected cases in each cluster that were infected by the reservoir. The number of first detected cases that were infected by the reservoir was 20 for all strains, three for H3N2v-M variant, and 17 for variants other than H3N2v-M.