

That’s not how your immune system works. Your immune reserves are not “spent” nor do they need to replace ones “lost”. It’s not like a military battle. Most pathogens are either destroyed or they avoid destruction through some mechanism - they’re not often fighting back against the WBCs.
Your immune system produces chemicals that make you feel like shit / tired, because it’s evolutionarily advantageous to feel like shit. This keeps you resting and away from others. This is also how medicines like NSAIDS or steroids can make you feel better, by inhibiting the processes instigated by WBCs. It’s not the disease that makes you feel bad, it’s your immune system (unless you’re deathly ill, we’re talking common cold/flu/COVID type stuff here).
It would be impossible for me to go in depth in immunology but your explanation is not at all in line with the evidence we have currently.

What illegal orders? This is a genuine question.
I’m an Army veteran and my wife is active duty. I do not believe any of the orders that have been issued thus far are illegal. The deployment to DC is potentially on some shaky legal ground, but that rests with the president and needs to be sorted out in court. Individual troops have no reason to refuse deployment to DC and the actions they’ve performed there, as far am I’m aware, are within the bounds for legal orders.
If one state deployed NG troops to another state, without the consent of the occupied state’s governor, that would be illegal. DC is a different situation because it can be under direct federal control and they have no national guard, as they do not have statehood.