Susceptibility of Influenza A, B, C, and D Viruses to Baloxavir

Baloxavir showed broad-spectrum in vitro replication inhibition of 4 types of influenza viruses (90% effective concentration range 1.2-98.3 nmol/L); susceptibility pattern was influenza A ? B ? C ? D. This drug also inhibited influenza A viruses of avian and swine origin, including viruses that have pandemic potential and those resistant to neuraminidase inhibitors.