While our study provides insightful implications, it is important to keep in mind its limitations. A key ingredient in an event study involves the date(s). Regarding the emergence of COVID-19, we make use of the official date of the declaration of the disease as a global pandemic by the WHO, i.e., March 11, 2020. Other studies look at the impact of other important different dates related to COVID-19 (e.g., Ashraf, 2020a, Ashraf, 2020bHeyden and Heyden, 2021), such as: (i) the date of the first COVID-19 confirmed case in the country; or (ii) the date of the first COVID-19 death in the country. Regarding key **data** on COVID-19 vaccines, we use a single date for each vaccine: when the vaccine effectiveness was announced as against the dates of vaccine trials. This choice is justified by the fact that vaccine development is a lengthy and uncertain process that generally takes around 10-15 years to complete before the vaccine can be mass-produced for public use (e.g., Chan et al., 2021). Despite the fact that the start of each phase marks a milestone in vaccine development because it (i) indicates the successful completion of the previous phase and (ii) boosts people's belief that the vaccine has a higher likelihood of progressing to the next stage, industry statistics show that only one-sixth of all vaccine candidates that undergo human clinical trials obtain final approval for mass production (Chan et al., 2021). Therefore, a more significant impact is to be expected when the vaccine is accepted by the regulators for mass population vaccination. We are aware that the magnitude of the impact of the emergence of COVID-19 and vaccine effectiveness announcements was influenced by the chosen dates.