If vaccine derived herd immunity were a realistic and proven theory; then there would be some scientific evidence behind it. After reviewing numerous studies that were claimed to represent and show the vaccine derived herd immunity theory to have a scientific basis; I conclude that there is NO scientific backing for the claim.
\Correlation equals causation, simply can not and should not be applied only where it benefits the intended promotional agenda, and then at the same time the same principal is disregarded, where it does not produce a conclusion favorable to the intended and thus promoted agenda. You can not have it both ways, and not lose major credibility, as to the level of existing bias.
What we can find is the backing for is the premise of natural herd immunity, because the majority of those thus becoming immune, have life long immunity. Any even 3rd grade science student, could comprehend the obvious validity of that basic concept.
The huge hole in the obviously incorrect concept of vaccine derived herd immunity, is exactly this. Vaccines do no provide increased vaccine derived antibody production, for life. Vaccines only provide relatively passive immunity, if and when they provide protection at all; and providing as well that over time the targeted pathogen has not mutated or changed to a point that the vaccine has become increasingly ineffective.
The second phase as to the understanding of why vaccine derived herd immunity is a myth, is to realize that thousands and if not millions of adults exist with having had no vaccines in decades. What are the odds that their childhood vaccines still protect them from polio, small pox, pertussis, diphtheria, measles, rubella, etc? Agreed, there is a big push in the recent past to give tetanus boosters to adults, which often includes the entire, DTaP.
But think of all the decades that have gone by where the ONLY people in that vaccinated herd, were the infants, and school children. In the recent past more of the CDC directive has gone to vaccination boosters for teens and college students, for certain, but limited numbers of vaccines.