The goal of this project is to test different messages aiming to increase willingness to get vaccinated against COVID-19. We designed two survey experiments. Both experiments are embedded in a Hungarian in-person public oppinion research conducted in September 2022 (N=1000). The first experiment tests two messages aiming to increase vaccine uptake amongst those who are still unvaccinated against COVID-19. The second experiment tests one message aiming to increase the uptake of booster shots of COVID-19 vaccines amongst those who received only the first round of vaccination against COVID-19, but did not get any booster shots. The Research Ethics Committee of the Centre for Social Sciences (Budapest) provided ethics approval for these experiments. Our study is funded by the Friedrich-Ebert-Stiftung Budapest. Our partner in data collection is a Hungarian public oppinion research company, Závecz Research. These two researches is included in a paper involving a third experiment that was carried out before (March 2021). This experiment was also preregistered. Preregistration is available at: https://osf.io/athrc Further information: https://osf.io/5e8mh/ The manuscript reporting the results of these three survey experiments was submitted to the journal Public Health.