Background: Vaccine hesitancy has been defined as a delay in acceptance or refusal of vaccines, despite the availability ofvaccine services. In the past, despite an impressive record of vaccine effectiveness in the United States, several factors havecontributed to a decreased acceptance of vaccines that has resulted in outbreaks of infectious diseases, e.g., measles. More recently, vaccine hesitancy has spread to coronavirus disease 2019 (COVID-19) vaccines. There are many causes of vaccine hesitancy, such as misinformation, fallacies, and myths, that have contributed to vaccine hesitancy.Objective: The purpose of the present report is to address the many causes of vaccine hesitancy and to suggest ways that the allergist/immunologist can be involved in the promotion of vaccine acceptance.Methods: The current COVID-19 vaccines were reviewed, together with their mechanisms(s) of action and adverse reactions to them.Results: The many causes of vaccine hesitancy include many doubts and concerns related to COVID-19 vaccines as well asa diminished level of confidence and trust by segments of the public in the nation's leaders in government, medical, and business communities, that those groups once enjoyed.Conclusion: Vaccination with COVID-19 vaccines is the only way that COVID-19 will be eliminated or at least controlled today, and vaccine hesitancy is the potential nemesis. The present report describes how the allergist/immunologist not only plays a major role in the delivery of specialized therapy of COVID-19 but also in educating the public with regard to the importance of COVID-19 vaccines, in dispelling misinformation, and in promoting trust for vaccine acceptance but must be informed with the most accurate and current information to do so.