Chronically Ill Roommates... How to Heal

Well, I don’t have University but that definitely sounds true to life. You can bypass the flu your whole childhood and get dropped by it your first semester at college. If your illness system comes from Get to Work, it should all just pass, with or without medicine. You can also just have the ones in your household drink lots of tea or OJ. You might want to try resetting the sims that you aren’t controlling or cheating out the buffs. If you have one of the illness mods, you’ll probably have to check in with the modder.

Also, in the past, having a doctor in the household made it more likely the household would experience illness.

If you make a pot of green tea and leave it out the other sims will autonomously drink it, and that helps them heal faster.