The human organism is remarkably complex. Just as there is a percentage effect in illness (there is always some proportion of the human population who - for reasons not always clear - is simply unaffected by whatever that illness is), there is no reason to believe this will not also be the case in terms of these vaccines. Different individuals will react differently.

If we want to go with the "eugenics" theory for the use of the vaccines in the global population, then perhaps - knowing the above to be true - the planners of this slaughter are not looking for absolute slaughter but merely to reverse the "growth" issue which leads to the growth curves keeping them up at night worrying about resource depletion. If they can put the global population on a declining trajectory rather than a growing one, that alone would have a pronounced effect over a period of decades.

This may be part of a long-term strategy rather than a "one and done" event.