MsOC, glad you are on the mend! It does sound like it was a bug of some kind, but it might have been made worse with vaping. Was the juice high in PG? I know it will do a real number on my throat. Did the vanillaz juice make you cough? There is currently a concern about "custard notes" in some flavorings, vanilla custard by capellas being one such flavor. Custard notes are particular compounds that impart a custard-like quality to the flavoring. But they are also implicated in irritation and/or lung damage, similar to the diacetyl problem that popcorn workers have gotten. Not at all likely your situation is anywhere nearly as bad as that incident, but its true that not all flavors are benign to inhale.
Back to the PG, though. It causes me not only throat and mouth problems, but also gastric issues too. I vape only VG juices now, and have none of these issues anymore. Too much nic will nauseate, for sure, but PG was a real problem for me, and is for many here. Looks like you have being around here for a while, so this might not be news for you, but thought I would ask anyway.