I hope you’re really not feeling timid about asking questions. Here’s an article
, available free in its entirety in pdf format and only 3 pages
, which has a nice discussion section on some of the work that’s been done linking viral and bacterial infections with relapses. It might shed some light on your question.
Personally I can say that when I got my flu shot last fall I was starting to have difficulty walking again within 2 hours of the injection. I was fine the next day, but I definitely learned that I do not want any infections, viral or bacterial, if I can avoid them.
Best of luck getting over this quickly. Maybe it’s also a matter of adapting to your new environment. I moved a number of times from one geographic area to another and it took several moves before I realized I would definitely be sick more than usual the first year whenever I moved to new surroundings/climate. Rightly or wrongly I just figured there were new and different bugs I hadn’t had an opportunity to fend off before.
Take care--I'm sure you'll do your best not to pick up the wrong things in Vegas.