Daly M, et al. - This research sought to evaluate changes in trust in vaccination and vaccine hesitancy. The data demonstrate that the development of vaccines indicating high effectiveness against SARS-CoV-2 has offered a way to protect against the health effects of the virus. They used logistic regression analysis with cluster robust SEs followed by the Stata 17 margins postestimation command to calculate percentage-point differences in the level of vaccine hesitancy between October 2020 and March 2021, with statistical significance defined as 2-sided P < .05. Yet national surveys imply that willingness to vaccinate declined throughout 2020 and may be insufficient to provide population immunity. The findings suggest that public trust in the development of vaccines and the government approval process represents a potential crucial reason for this hesitancy.