Corrected entry: When L.J. is bitten he manages to suppress becoming a zombie for 1-2 days. When Carlos is bitten by L.J. he is infected so quickly and talks about it "being too late for him" (whereas in the previous film he had 3 hours before getting the antidote). Why is this different now and why is Carlos not still carrying the antidote in him?
Doddi
17th Nov 2016
Correction: The t-virus was modified by her blood, as explained in the latter part of the movie. Therefore his blood would have no natural immunity, and this would explain why it infected at an accelerated rate.
I'd like to point out Carlos was bitten by LJ, and not one of the advanced Tmuts. BUT there was a jump scare shot where Carlos may or may not have been also bitten by an advanced one shortly prior to LJ biting him.