XK and influenza: Therefore, influenza plasmid-based reverse genetics (Figure 4) represent a better, faster, and flexible alternative, allowing the rapid generation of virus containing the six internal segments of a high growth PR8 (IIV) or A/Ann Arbor/6/60 H2N2 (LAIV) and the two surface HA and NA glycoprotein segments from the WHO candidate [40,126].