I had unconfirmed, but odd symptoms in late 2019, early 2020. Two weeks, I was unusually fatigued and literally laid down in bed all the time. Even just reading an email on the phone just felt so irksome that I could not be bother to read them nor take a single call. Walking up the stairs quickly fatigued me. Even after the acute symptoms wore off, my mind and brain felt kind "short on something", like it just didn't want to really think. Ultimately, that was very costly even into the present day, because I would have helped my mother draft text messages instead leaving the texting to her own devices...and that's why she and I got hit with a conversion lawsuit(and why I'm stuck paying for a Westlaw subscription)....
I got hit with a confirmed case in Feb 2021. The symptoms were similar to the unconfirmed case but more severe but lasted even a year. It actually still affects me to the present day. I don't like driving around more than necessary these days. Used always love the travel. I cannot eat a high starch diet and function like I did in the past before the infection. I basically have to fast to get back to a "clear mind" state. I also never liked the heat, but more sensitive to hot days, especially for that summer of 2021.
Vaccination was not an option because I was younger, and the supplies were reserved for the older crowd at the time.
Gizmo might be better off as it has evolved to "deal with" humans, so maybe the potential for such significant yet hard to prove cell damage won't hit him that hard.