Air travel is a luxury compared to the availability of antibiotics, and not getting plague.
Vaccines aren't made for epidemics: they are for _endemic_ diseases, and especially the ones which target children. Vaccines are good for things like polio, smallpox and Measles. But plague, Cholera, SARS, etc. are delt with emergency measures: quarantine, not vaccines.
The problem (and there is indeed a problem) with antivaxs, is child mortality, not «plague-like epidemics».