By Dec 1 2017 I had already had three terrible colds - debilitating and long lasting. I confirmed with an American doctor living in Milan that your body needs time to adjust to the strains of illnesses specific to a place, and as such it was normal for a newcomer to fall ill often until they build immunity.
Also, public trans (subways, trams, buses) are fantastic incubation pods for every plague flashing through the day cares and elementary schools -- the air you breath as well as all the surfaces, doors, card readers, hand rails, etc.
In Radom, though much colder than Milan, I haven't been sick once yet, even though I'm surrounded by plague carriers all day every day. I'm attributing this to taking mostly private cars and walking. And taking a big dose of Emergen-C every freakin day!
(Don't ask me if I'd rather be in Milan even WITH the probability of plague... Let's not go there...)