triggering altruism increases the willingness to get vaccinated against covid-19

introduction: once a vaccine against covid‑19 is available, the question of how to convince as many people as possible to get vaccinated will arise. we test three different strategies to reach this goal: two selfish motivations (highlighting personal survival risk or the inconveniences in the event of getting infected) and altruism (reducing the danger for individuals who cannot be vaccinated or remain vulnerable even after getting vaccinated). methods: we conduct an online experiment with n = 303 subjects (64% female, 79% university students, average age 26 years) with the three aforementioned treatments and compare the treatment effects on vaccination willingness with the baseline. results: results suggest a positive effect of all treatments, but the treatment where reducing the danger for individuals who cannot be vaccinated was highlighted was by far the most effective. conclusion: this result implies that this rarely discussed aspect should be given more attention to increase the willingness to get vaccinated against covid‑19.