https://youtu.be/soIrKqnEykY
Unlike most vaccines which are a modified virus or viral protein to elicit an immune response, the Moderna and Pfizer vaccines use messenger RNA, mRNA, to instruct the body to begin defending itself against COVID-19.
“What’s different about mRNA is it’s a genetic vaccine,” Dr. Weissman told Action News.
https://6abc.com/covid-19-vaccines-moderna-pfizer-university-of-pennsylvania/8882216