As I hear it, this song has hardly any chord changes at all. Almost all of it is on the one (tonic, or "I") chord, plus a couple of brief changes to the VII (dominant seventh), at the syllables italicized below:

Well, won't somebody tell me, answer if you can
Won't somebody tell me, tell me what is the soul of a man?

In the key of E, the two chords would be E and B(7); or, in other keys,...
A and E(7)
C and G(7)
D and A(7)
G and D(7)
etc.

I've felt for a long time time that one-chord blues songs (e.g., John Lee Hooker's oeuvre), and simple two-chord songs like this one, are among the most difficult blues numbers to play well. Just strumming the chord(s) doesn't really "get it." You need to learn, or to approximate, the fingerpicking and/or the slide technique of the original.