It is a very strange disease. My Uncle and his wife had it and did not notice it at all. My cousin husband and daughter got it hard. Did not effect my cousin at all.
Hopefully my genetic makeup has the good stuff to fight the virus.
most diseases act this way.
Your genetic makeup, your health, weight and age matter.
And also the amount of viroids you get initially also play a factor.
Add in environmental factors and even pure dumb luck