Immunity if bit again?

yep - auto-immune is defo a big player in lyme patients - horowitz says the majority have some kind of autoimmune issue - hashimotos the most common - something like 60% from memory in his patient population.
intracellular chronic infections really mess with the immune system - via inflammation and molecular mimicry etc.
also, acc to most recent research, gut permeability is involved in all AI illnesses - something tick born infections increase dramatically.

ref why some people do not get ill - immune status i belie is the largest variable - imagine how we lived for the majority of human history - all but the last 2000 years inmost places we would have slept in huts or caves etc along with animals and their parasites - everyone was exposed. why are we sick now? - modern life, is not conducive with good health - and so more people become sick.
most of us can point to some event that gave our immune systems a beating before we became ill. trauma, stress, illness, surgery, etc etc

why can you clear covid - but not lyme etc - well each bacterial infection impacts the host in ways that favour it - but not necessarily other infections - like viruses.
as an example - in the 7 years i have been ill i never had any obvious sign of a respiratory virus - until i got 50% recovered - then i have had 3 in 5 months.
the reason is that viral pathogens survival "strategy" are different to chronic bacterial infections spread by arthropods.
- respiratory viruses are designed to spread from person to person v quickly and easily - and do not need persistent infection to survive - a few days is enough.
arthropod born infections on the other hand need to survive inside hosts for v long periods - even years - to wait for another arthropod to come along bite them and then bite another animal to ensure survival - hence they evolved ways persist long term.

Hat is interesting about researchers of biomagnetism, is they believe bacteria, viruses, fungi, parasites are resonating with one another in tissues and organs . It this communication that helps to keep them viable.