Immunity system complexity (Introduction)

by David Turell , Thursday, June 18, 2020, 19:01 (1398 days ago) @ dhw

DAVID: All diseases can be handled by several immune mechanisms; outright killing (engulfing bugs) and antibodies to kill or neutralize. The instructions are in all immune cells for these actions. No program for all possible present and future bugs. Anything that comes along can be dealt with by present limited responses.

dhw: You are simply telling us what an immune system does – it kills or neutralizes the enemy. But the enemies are all different! Our highly intelligent scientists are now trying to find a way to get rid of Covid-19 because the immune system’s library of responses – accumulated from all its past experiences – does not contain “instructions” on how to deal with the new enemy.

DAVID: Of course our immune systems don't know it. It is a novelty!!! Yet we know herd immunity can develop. But we want human invented vaccines to speed the herd immune process. The instructions for herd immunity are there, just too slow to save more lives, so we step in.

dhw: Every disease in life’s history was once a novelty! And so (1) the immune system has had to come up with new answers every time, thus building its library of responses. “Herd immunity” and speed are not the point! If “all diseases can be handled by several immune systems”, how come people are still dying of cancer, flu, malaria, AIDS….? (2) Once again, I suggest the immune system does NOT contain instructions on how to counter all diseases (“anything that comes along can be dealt with by present limited responses”) but accumulates its own instructions in an ongoing learning process.

You are close to finally understanding immunity. The first bold is correct, but unfortunately not the second. Immune cells contain all the instruction they will ever need to fight all and every infection, most with permanent blockage. There are unfortunately some viruses that constantly mutate each year, corona viruses as common old and the flu, requiring new antibodies to develop each year. In TB, leprosy, and lyme disease, the bugs are in a very strange family that is difficult to fight. Luckily there are treatments, but never full immunity. Only TB can be stabilized without drugs: the body immune system calcifies walls around the TB colonies. The TB does not advance unless the person is weakened somehow and the calcium breaks down.