Introduction COVID-19 vaccines significantly reduce the risk of complications and hospitalizations due to this virus. When COVID-19 vaccines first became commercially available, roughly 30% of U.S. adults reported being hesitant to receive these newly developed vaccines, and 15% said they would not receive the vaccine. However, by May 2021, 19% of adults were vaccine-hesitant, and 13% refused to vaccinate against COVID-19. It is critical to understand why adults’ degree of willingness to vaccinate against COVID-19 changed over time to plan for future pandemics and vaccination campaigns. Methods We conducted two waves of survey research over five months (January and May 2021) with a panel of 890 U.S. adults. One survey question assessed willingness to vaccinate against COVID-19. The response option included a slider scale ranging from 0 (signifying complete unwillingness) to 10 (complete willingness). We asked participants whose willingness score changed by more than one point to report their rationale for their change in perceptions. We conducted a conventional content analysis on all qualitative responses. Results We analyzed qualitative responses for 289 participants, 54.7% of whom had not been vaccinated against COVID-19 by May 2021. Among those who remained unvaccinated, 36.1% reported increased willingness to vaccinate. The most commonly cited reasons for becoming more willing to receive the vaccine include believing that COVID-19 vaccines are safe and effective, protecting against the pandemic, and desiring to return to pre-pandemic life. Reasons for increased COVID-19 vaccine hesitancy include vaccine safety concerns, the low perceived need for the vaccine, distrust in how COVID-19 vaccines are made and of larger institutions such as the government and pharmaceutical companies, and concerns about vaccine effectiveness. Conclusion Findings illuminate the rationale behind individuals’ changes in their degree of willingness to vaccinate against COVID-19. It is critical to incorporate these considerations in future vaccine rollout initiatives to increase the public’s vaccine confidence.

In early 2022 in the U.S., rural adults were the least likely to vaccinate against COVID-19 due to vaccine hesitancy and reduced healthcare access. This study explored the factors influencing rural adults' COVID-19 vaccine perceptions and their acceptance of pharmacist-administered vaccination. We utilized phone-based semi-structured interviews with 30 adults living in rural regions of one southwestern state and analyzed the data using a team-based thematic analysis approach. Vaccine-willing participants described knowing other people affected by the virus and their desired protection from the virus. They reported trusting scientific institutions and the government to provide safe vaccines. Vaccine-hesitant populations, however, feared that the COVID-19 vaccine development process had been rushed, compromising the safety of these newer vaccines. Although they differed in the news sources they preferred for receiving COVID-19 vaccine information, both vaccine-willing and vaccine-hesitant participants described trusting local authorities, such as healthcare providers and county government officials, to provide accurate COVID-19 vaccine information. Regarding the acceptability of pharmacist-administered COVID-19 vaccinations, all but one participant described their acceptance of this healthcare delivery approach. Future outreach should leverage rural adults' trust in local sources, including community pharmacists, deemed more convenient access points to healthcare, when addressing vaccine hesitancy.