Do you really think of any natural species, some of them around for a few hundred million years, being self-vaccinated? No the nature is "cruel" , large percentage of babyseals and other baby mammals (to stick with our league) simply won't make it into their first year. Do you really think that the human genepool is advanced by artificial fertilization techniques, flue shots by big pharma and what have you in the environment full of toxic waste/pollution in the air/water/food which react with it? The answer is NO.
Perhaps, I'm the odd bird a "self-hating" human lol.
But with my medical record involving numerous surgeries (ok partly accidents), child asthma (cured/stabilized) and other stuff I simply know that it is not very fair to pass such predicament on the next generations just for some silly/selfish "paternal/maternal" instincts and urges, especially with the looming correction, ehm die-off.
Moreover, you can invest love in so many other beings already around you, incl. kids from your wider family/clan area or the poor of the world, if that floats your boat better.
I'm glad SeaGypsy started this topic, I guess this very area is going to take most of the psycho toll on the starving world as we submerge into the net energy darkness. This might take suddenly utter prominence for many over their guns, pm, gardens and what have you on your personal to-do top list.