Moderna’s latest vaccine results are promising—but it’s still too early

Drug maker Moderna has just announced encouraging interim results from the ongoing phase 1 trial for its experimental coronavirus vaccine. The early results suggest the vaccine has the potential to confer immunity against covid-19 in people.

What is the vaccine and how does it work? Moderna specializes in vaccines designed to elicit an immune response against the coronavirus through the virus’s mRNA—genetic instructions for the virus to replicate inside the host. New methods like Moderna’s are fast to prepare, but they have never led to a licensed vaccine for sale.

The phase 1 trial: The purpose of a phase 1