I'll add to the links my own n=1 anecdote: when I got covid, the immediate sickness was not worse than a cold, but then during the time ~2-4 weeks after, I had noticeable brain fog. 10h sleep/day, work was slow, chess rating dropped 170 points.
(My story is far from the worst)
我将在链接中添加我自己的 n=1 轶事：当我感染新冠病毒时，直接的疾病并不比感冒更严重，但是在大约 2-4 周之后的时间里，我有明显的脑雾。每天10小时睡眠，工作缓慢，国际象棋等级下降170分。
（我的故事远非最糟糕的）