Can I make a game like plague.Inc in UE4?
Please share your opinion.
Absolutely. I’ve seen a few people working on card games/word games in UE4 already. Other than confirmation that its possible, I’m not sure if you are looking for anything else, but yeah, definitely do-able. Essentially any game could be reproduced in UE or created from scratch. There isn’t much it can’t do.
A word game could be any number of things so thats an incredibly vague question. Also im not sure how Plague.inc would in any way be considered a word game though so really not sure what you are attempting to achieve.
Short answer regardless is that yes it can definitely be done in Unreal, being able to is a different question.
by widget blueprints (UMD) and hud.
Sprites and planes textures.
and a fixed camera with a pawn player invisible.
i think is the best way to start with. If there is an another way , let me know too.
I want to make something like plague inc 
I have the idea with making a game, the idea of this game just like the plague.Inc,So i wonder how the Plague.Inc made
Still not really an answerable question. But yes. You could replicate plague.Inc in blueprints and Unreal Engine if you wanted.