Covid vaccine

[cannongal]

I'm really confused about this covid vaccine,  and I hope that someone who is smarter than I,  and has a lot of patience can explain it to me.  If you've already had covid, why would a vaccine be necessary?  Also, if you tested positive for covid more than once, what makes you think that the vaccine will work?

Here's a question I think is even more important: if vaccines are safe, as we are constantly being told, why have the manufacturers been shielded from liability?

You are an idiot.   Vaccine manufacturers have been shielded from liability since the 70's.  Look it up. 
Meh