Mobile vaccination units substantially increase COVID-19 vaccinations: evidence from a randomized controlled trial.

Background: Governments around the world used mobile vaccination units (MVUs) to increase COVID-19 vaccine uptake, but the causal effect of MVUs has not yet been evaluated.

Methods: In a randomized controlled trial (RCT) with 20 Swiss communities (10 treatment, 10 control) in August 2021, MVUs were sent to treatment communities for 4 hours on a single day. The experimental sample comprises 20 414 adults who were unvaccinated against COVID-19 at this point.