Shutterstock A listener wants to know about the different coronavirus vaccines -- whether currently available or still being tested. This week's first and only question has a very involved answer. Barbara Buser from Brunswick Hills asks, "There are various types of vaccines being developed: how are we to know which one is best?" "The first vaccines available right now work with a new technique that’s never been approved before, using messenger RNA. And they're very elegant, simple vaccines," St. Clair said. "A little bit of messenger RNA that codes for the spike protein is encapsulated in a little fatty droplet -- a nanoparticle that goes into your body and is absorbed immediately into your cells, which begin producing the spike protein. I am likening these to a ‘Tesla’: it's really cool and slick, but the only problem is that you can't plug it in everywhere," St. Clair said.