It is immoral from almost any point of view to refuse to defend yourself and others from very grave and terrible threats, even as there are limits to the means that can be used in such defense.
I just take the Bible for what it is, I guess, and recognize that I am not a scientist, not trained to be a scientist. I'm not a deep thinker on all of this. I wish I was. I wish I was more knowledgeable, but I'm not a scientist.