My husband got his 3rd Pfizer dose on Friday. For him it's immune compromised reason. They sent him to get that shot then he went up for his first Chemo treatment. So far so good on handling both the 3rd dose of Pfizer and Chemo. He did also have Covid a year ago (mild case with long haul symptoms). Hopefully the issues from the 3rd dose your suffering from will clear up quickly.I agree and that's why people took smallpox and measles vaccines regardless of current exposures.
As a personal notation: just took my 65+ booster of Pfizer. The first two shots I had some soreness but aside from taking a planned lazier-than usual day; no other ill effects. This dose was fine day one, with a sleepless night. Day two started out fine so I did outdoor work but ended up with a sleepless night due to low oxygen uptake. I had to concentrate to breath and that restriction is not reassuring. Walking the dog today we had to stop several times and the light-headedness led to the pukey feeling. Very tough to get benefit from even a deep breath, yet no congestion or typical lung obstructions. I can only conclude that a full blown Covid infection would be a horrible way for a fitness trainee to suffer through, even a mild one.