XK and influenza: Neuraminidase inhibitors (NAIs), such as (1) orally administered oseltamivir (Tamiflu); (2) inhaled zanamivir (Relenza); and (3) intravenously applied peramivir (Rapivab), are FDA-approved anti-influenza drugs that act by inhibiting the sialidase activity of the IAV/IBV NA, thereby inhibiting the release of progeny virions from infected host cells [292].