Comment by daun

I was actually wondering about this because both the Spanish Flu and the 2009 H1N1 pandemics left life-long brain damage for some survivors in the form of narcolepsy with cataplexy. The vaccine for H1N1 caused it in a very small amount of patients as well. After the Spanish Flu they called it "encephalitis lethargica". It appears that it damages the hypothalamus.