There are three main platforms that vaccine manufacturers are using to develop COVID-19 vaccines. A central theme is that all vaccine candidates are focusing on developing immunity to the “S protein,” a component of the COVID-19 virus that is critical to allow itself to attach to receptors within our body and infect our cells. By developing vaccines that promote an immune response in our body against this specific protein, the available clinical trial data has shown encouraging results in preventing significant disease and/or transmission. Another difference between the candidates is differing storage requirements which could vary from simple refrigeration to deep freezing. vaccine