@chenando1 @Otong777
We agree that the virus causes the sex change.
Because Hinata can infects other with the virus proves the virus is still in his/her body.
If we assert that the others infected people don't change back when re-infected by Hinata, it may be because they are always infected by the same virus. It's like adding water in a bottle of water : there's only water in the bottle.
So an answer to change back is to suppress the virus in one's infected body.
We also need to know if an infected (not Hinata) can also spread the virus. If not, it may change drastically the way this virus works.
And if Hinata's virus mutate, this new one could affect already infected ones and rewrite the sex change by another.