もう、ゾフルーザに関して、ウイルスの変異による耐性化のリスクが示唆されてますよ。

Characterization of influenza virus variants induced by treatment with the endonuclease inhibitor baloxavir marboxil

Baloxavir acid (BXA), derived from the prodrug baloxavir marboxil (BXM)

Here, we characterize the impact on BXA susceptibility and replicative capacity of variant viruses detected in the post-treatment monitoring of the clinical studies.

We find that the PA I38T substitution is a major pathway for reduced susceptibility to BXA, with 30- to 50-fold and 7-fold EC50 changes in A and B viruses, respectively.

https://www.nature.com/articles/s41598-018-27890-4