SARS-CoV-2 transmission has resulted in the continuing global covid-19 epidemic. By November 2021, more than 250 million people had been diagnosed with covid-19, and more than four million people had died around the world. Covid-19's morbidity and mortality, as well as its comorbidities and wide-scale economic impact, have motivated vaccine research at an unprecedented rate. New technology m-rna vaccines like BNT162b2 (Pfizer-BioNTech) and m-rna-1273 (Moderna), non-replicating viral vector vaccines like Janssen's Ad26.COV2.S (Johnson & Johnson), and traditional inactivated whole virus vaccinations like CoronaVac have all been licensed for use thus far (Sinovac Biotech).
