The struggle against COVID-19 has witnessed vaccine growth move at a record rate, with over 170 unique vaccines in trials. However, how are they different from one another, and how can they protect us against illness? The way that it works. mRNA vaccine (Pfizer, Moderna), DNA & Societal vector vaccines (Johnson & Johnson (J&J, JNJ), Oxford-AstraZeneca, Inovio, Sputnik V); protein/peptide vaccine (Novavax, EpiVacCorona), traditional inactivated (CoronaVac of Sinovac, Covaxin). Mechanism of every kind of coronavirus vaccine clarified.