[Socks]

I might not be remembering this right but when Millie first came to Thundeclan I believe she said she couldn't get infected by greencough because of twoleg medicine. Yet, later on, she gets whitecough which develops into greencough and she gets really close to death.

I wonder if this is like the flu, it keeps evolving and changing so every flu season we get shots for which type of flu they predict will be going around.