“but for some reason, the antibody fails to neutralize the infectivity of the virus “
Because the “vaccine” is crap.
It’s not that the vaccine is crap. Per se.
Keep 8n mind that the mRNA vaccine only produces antibodies for the spiked protein antigen as part of the virus, not the entire virus.
When you have the virus, the antigen particles will be a diverse array of virus particles, not just one part.