  Twitter, prompted by the rapid spread of alternative narratives, started
actively warning users about the spread of COVID-19 misinformation. This form
of soft moderation comes in two forms: as a warning cover before the Tweet is
displayed to the user and as a warning tag below the Tweet. This study
investigates how each of the soft moderation forms affects the perceived
accuracy of COVID-19 vaccine misinformation on Twitter. The results suggest
that the warning covers work, but not the tags, in reducing the perception of
accuracy of COVID-19 vaccine misinformation on Twitter. "Belief echoes" do
exist among Twitter users, unfettered by any warning labels, in relationship to
the perceived safety and efficacy of the COVID-19 vaccine as well as the
vaccination hesitancy for themselves and their children. The implications of
these results are discussed in the context of usable security affordances for
combating misinformation on social media.
