My layman understanding is that a vaccine relies on the body creating antibodies.
My layman understanding is that a vaccine relies on the body creating antibodies.
But that doesn't mean that it is impossible to create a vaccine: this problem exists already for successful vaccines. For example, the Hepatitis B vaccine has a relatively high failure rate, but is still provides immunity 90+% of the time. It just means that some smallish percentage of the people you vaccinate aren't actually contributing to population immunity.
See below for more info:
https://en.wikipedia.org/wiki/B_cell
https://en.wikipedia.org/wiki/Memory_B_cell
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3760154/ --> this one is particularly good. A lot of good info in here on how vaccination and "memory" interact.
https://www.sciencedirect.com/science/article/pii/S0264410X0...
EDIT: this one covers the major routes of vaccination failure --> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4962729/#!po=60...