system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are diseases such as chickenpox and measles more deadly to adults than they are to children?

I can't speak for America, but in the UK children are encouraged to catch chickenpox when they are young as they can recover fairly easily from the disease at that age but would be at much greater risk if they were to contract the disease as adults, but surely our immune systems get stronger with age?
gpt
That’s actually the problem. If the immune response is too strong, it can wear your body down more. The aches and crummy feeling you get when you’re sick aren’t caused directly by the pathogen, they’re a result of what your immune system is doing.