  We propose a model describing the synergetic feedback between word-of-mouth
(WoM) and epidemic dynamics controlled by voluntary vaccination. We combine a
game-theoretic model for the spread of WoM and a compartmental model describing
$SIR$ disease dynamics in the presence of a program of voluntary vaccination.
We evaluate and compare two scenarios, depending on what WoM disseminates: (1)
vaccine advertising, which may occur whether or not an epidemic is ongoing and
(2) epidemic status, notably disease prevalence. Understanding the synergy
between the two strategies could be particularly important for organizing
voluntary vaccination campaigns. We find that, in the initial phase of an
epidemic, vaccination uptake is determined more by vaccine advertising than the
epidemic status. As the epidemic progresses, epidemic status become
increasingly important for vaccination uptake, considerably accelerating
vaccination uptake toward a stable vaccination coverage.
