I neet to correct this because pandemics are NOT a "relatively new" phenomenon. Maybe it's not quite clear what pandemia actually means so here a quote: "A pandemic (from Greek πᾶν pan "all" and δῆμος demos "people") is an epidemic of disease that has spread across a large region; for instance multiple continents, or worldwide."
Examples are the Plague of Athens, The Black Death, or The Spanish Flu. Now I don't want to compare Covid-19 to those examples because it still caused fewer deaths than any flu virus in prior seasons. It is just very contagious and shouldn't be taken lightly. To say that it didn't spread that rapidly in Europe yet...well, Italy was hit the worst. There also are cases in the northern part of Germany (it started in the south and it's unknown yet how those people in the north got infected), France, Spain, Austria... So it doesn't really matter were fans come from or if they go to a country which is "not a hot spot for the virus." That all can change in just a matter of time so it would seriously be the best decision (in my opinion) to cancel/postpone the event.