Anecdotal evidence but I have collected the 4 big strains and albeit vaccinated correctly it was quite the hassle each time (a week in bed or more), and yeah short of breath and more after each (once for around 3-4 months with brain fog, with the addition that I didn't really feel spicy food at all spicy during that period, just very good).

It's definitely not a joke and I hope I won't catch it again.