Lessons learned from the successful polio vaccine experience not learned or applied with the development and implementation of the COVID-19 vaccines.

The eradication of polio during the latter half of the 20th century can be considered one of the greatest medical triumphs in history. This achievement can be attributed to the development of vaccines that received the public's almost unwavering acceptance of them, especially by parents who had been waiting/hoping for a medical breakthrough that would ensure that their children would not succumb to the devastating effects of infantile paralysis. Sixty years later, the worldwide population was now confronted with an equally devastating disease - Covid-19 - which by the 2020-2021 time period had reached pandemic levels not seen since the flu outbreak of 1918. Unlike polio, however, several vaccines against Covid-19 were rapidly developed and deployed due to advances in microbiologic and immunologic technology. But also, unlike the polio vaccine experience, there was not universal acceptance of the Covid-19 vaccines and this has led to continuation of the pandemic into 2023 (albeit at a reduced level). In addition, acceptance of the Covid-19 vaccines has been confronted with the uncertainty that they do not apparently prevent transmission in asymptomatic people, and the mutation rate of the virus requires periodic re-evaluation and possible upgrading of the vaccines. This review will focus on the various factors that have led to these contrasting attitudes toward these two different vaccines and how resistance and hesitancy to vaccine use can be overcome by implementing various measures, after introducing the key roles that the sciences of microbiology and immunology have played in vaccine development over the past 250+ years.