Over the course of 2020, the world watched with bated breath as biotechnology companies—in less than one full year—developed, tested, and released vaccines against the SARS-CoV-2 virus that causes COVID-19.
In some ways, these vaccines upended the paradigm of vaccines that came before; they were deployed on a faster timeline and it was the first time mRNA vaccines were used and mass-produced. But the science behind all COVID-19 vaccines rests on decades of research on infectious diseases, the human immune system, and vaccination.