Infection rate is really not a rate but more correctly an infection progress, like filling a glass with water. The mod reports this progress as a number between 0 and 1, with 0 being just infected, and 1 being a zombie. Once the water overflows the glass, you are dead. This is a vanilla feature and the mod only modifies how slowly you get there since the water level can only go up. It delays the inevitable by moving the infection time forward relative to the total hours survived.

Ex: You survived 1000h (call it T) and was infected at 999h (call it V) and you are supposed to die at 1050h (call it X) because you had 51h to live (call it L, the vanilla game assigns this number from a range every time you get infected). Every hour in game, T will increase and the (T-V)/L will slowly get to 1. The mod delays this by increasing V since the interval L is fixed. How much the mod delays depends on the progress of the disease, the quality of the vaccine, and how many albumins you have taken, which also depends on the quality of the vaccine.

After you can't take albumin anymore, you just take another dose of the vaccine to reset the infection progress. A vaccine cure of course instantly cures you, however, it is much more expensive to make.

So the best strategy is to not take the vaccine when you just bitten. You should take blood test to gauge you zombification progress. Once you get to about 70-75%, take the best vaccine you have. Then do the albumin course to prolong the effectiveness of the vaccine (on ~50% infected level).

Remember, that the disease progresses regardless of whether you are vaccinated or not. It can only be arrested or slowed by the taking of vaccine and subsequently albumin to prolong the vaccine effect.