> When naive B cells see that existing antibodies are already present I don't think this is how this works. They "see" antibodies sticking to a target, as suc

> When naive B cells see that existing antibodies are already present I don't think this is how this works. They "see" antibodies sticking to a target, as successful antibodies are presented for replication and refinement. This implies a functional response. If the vaccine antibodies wouldn't work on a new strain, the B cells wouldn't recognize them as suitable candidates.