from my understanding the virus continue to exist in the cells of the nasal surfaces well after (like weeks) the immune system has already beaten it up inside t

from my understanding the virus continue to exist in the cells of the nasal surfaces well after (like weeks) the immune system has already beaten it up inside the body. That virus naturally continues to attack the body from those surfaces and thus continuously triggers the immune system resulting in that low-symptom prolonged period in the people with normally working immune system.