Well, specifically it said he "attempted to immunize himself against 13 diseases", which isn't equivalent to actually doing that. Furthermore, I get the sense t

Well, specifically it said he "attempted to immunize himself against 13 diseases", which isn't equivalent to actually doing that. Furthermore, I get the sense that his isolation was primarily to avoid the authorities ("he stayed not at the Lalaji but secretly—and illegally", use of the word "safehouse"), and not due to biological concerns. If anything, that was a second order benefit in his mind - "The benefit of that is that I was essentially in quarantine"...