Almost a year after the worldwide appearance of the coronavirus (SARS-CoV-2), several novel vaccines of diverse platforms have been successfully developed and administered. Two mRNA vaccines represented a new type of vaccine that comprised of synthetic mRNA molecules containing the code sequence necessary to build the SARS-CoV-2 spike protein. These mRNA vaccines almost single handedly carried the brunt of the US COVID-19 immunization strategy during the past three years. The known and potential benefits of COVID-19 vaccination outweigh the risks and adverse complications. The ongoing COVID-19 pandemic has stimulated unprecedented research on aspects of the vaccines’ ability to reduce the risk of severe infection and death. Likewise, basic immunological studies are pivotal to unraveling the potential and long-term effects of the vaccines as well as to be able to make adjustments to new vaccine development. As the circulating virus strain continues to evolve, updated vaccines will be critical to protecting the population, particularly the elderly and immune compromised.