"On the face of it, it doesn’t make sense. Once you get infected by a pathogen, your body should be better prepared to deal with it the next time it comes around, but instead of being better at fighting off the invader, people with long COVID are getting more hammered by it the second (or third or fourth) time around."
Source: https://www.healthrising.org/blog/2023/11/24/re-infection-long-covid-chronic-fatigue-syndrome/?