A recent study dealing with Western European countries suggests a connection between vaccine skepticism and support for populist parties (Kennedy 2019). Of all countries in the study, Italy scored highest on both counts, with 44% of the electorate voting for populists in 2014 and 14% of the population not deeming vaccinations important. The study concludes that both phenomena have a common root in the distrust of elite and experts. While that seems plausible, this paper establishes that there is much more (...) to be said about the relation between populism and the anti-vaccination movement. Using the case study of the Italian anti-vaxxers, I spell out how populists have reinforced an echo chamber in an effort to mobilize it. I argue that besides the common root cause, in this instance there is also indication of a causal relation between populism and anti-vaccination. Moreover, I show that populism and echo chambers in general are conceptually linked through their dichotomous division of society and rejection of legitimate opposition. (shrink)