Scientists are trying to figure out why the vaccines work so well

Two decades of research went into making mRNA vaccines that are perfect for battling coronaviruses, right down to figuring out the best kinds of fatty molecules to cushion the genetic material within each shot. “NIH did a great job at identifying exactly what part of the virus to use and exactly how to stabilize it in a form that makes the immune system recognize the most important part of it,” Wherry said. That form is the “prefusion” stage of the spike protein, which is seen just at the moment where the spikes unfold and shape-shift to dock onto the cell surface. Interrupting this stage of an infection is like jamming gum into a keyhole, Wherry said. “You can stick gum all over a door and it might not do anything, but if you put gum in that keyhole, a key isn’t going to fit in there to open that door.” Researchers knew about this vulnerability because of work done studying other viruses over the last decade. NIH scientists delivered a blueprint of this form of the spike protein to pharmaceutical companies so fast — within days of first seeing the coronavirus genome in January — that safety trials in people were already underway by April.