IFNA1 and infection: Specifically, the Richards growth model [35] is employed to describe the dynamical relationship among viral accumulation, infection activation, and a hypothetical innate-immune-system defence mechanism orchestrated by neutralising antibodies (NAbs), and potentially enhanced by the interferon (IFN) system (for reviews covering the crucial roles that NAbs and the IFN system play in disrupting SARS-CoV-2 pathogenesis, see [36,37], respectively).