I'm not either, but it does say "small changes in cognition and memory that persist for at least a year" so possibly the additional good news is that a) there is no clear evidence for major, long-term changes, and b) there is no clear evidence that even the small changes last more than a year.

An experiment can't reach beyond its own bounds so there's no proof here in either direction - we can't confirm from this that the changes persist past a year but there's no reason to suppose they don't. It also can't say anything about cumulative infection but other studies suggest that's worse.