Messenger RNA—or mRNA—vaccines have been in development for decades, and are now approved for use against COVID-19. Here’s how they work and what you should know about them. Visit https://www.jhsph.edu/covid-19 for even more resources.

Messenger RNA—or mRNA—vaccines have been in development for decades, and are now approved for use against COVID-19. Here’s how they work and what you should know about them. Visit https://www.jhsph.edu/covid-19 for even more resources.