This vignette-based study (N = 15466; Mage = 51.65) examined how health care workers could foster reflection about and intentions to get vaccinated against COVID-19 by experimentally varying their communication style (i.e., autonomy-supportive vs. controlling) and the reference to external strategies (i.e., use of a monetary voucher or corona pass vs. the lack thereof). An autonomy-supportive, relative to a controlling, communication style was scored as more effective and came with more reflection about and intentions to get vaccinated due to enhanced autonomy need satisfaction. Vouchers were perceived as a less effective strategy than the corona pass, thereby even impairing reflection and vaccination intention relative to a control group by forestalling the need for autonomy. Especially hesitant citizens were prone to the negative effects of a controlling style and vouchers, while refusing individuals were less affected by any type of motivational attempt. The findings highlight the critical role of autonomy support in promoting reflection about and a self-endorsed decision to get vaccinated.