i need answer like how is the mc immune????

I think it has something to do with his blood and genes, cuz the nurse is taking his blood for blood test at the end

Maybe its the biology major in me, trying to reason with it… but it could actually make sense if we were to assume the mc’s physical body didn’t reset every time he died. In this case, because MC has been exposed to the virus more than once, his body was able to produce memory cells of the virus and created an antibody against it. Which would make him immune. It would also make sense why he of all people were immune if his body just had that mutation built in bro is just built like that