Fig. 2
From: Animal models for the risk assessment of viral pandemic potential
The ingredients and recipe of influenza virus pandemic. The workings of the five ingredients of IAV pandemics are depicted. The ingredients are numbered (1) through (5). Avian IAV, swine IAV, and human IAV are given as avIAV, swIAV and huIAV, respectively. The viruses generated through (1), (2), and (3) may have a diverse range of transmissibility. When a virus with a nonhuman origin HA and an efficient human transmissibility gets transmitted from the adaptation host swine to human (4), a pandemic might ensue (5)