While the concept seems simple, it required decades of work for mRNA vaccines to overcome a series of hurdles.
First, scientists learned how to modify mRNA so that it did not produce violent immune system reactions.
Second, they learned how to encourage immune system cells to gobble up the mRNA as it passed by in the blood.
Third, they learned how to coax those cells to make large amounts of the critical piece of protein.
Finally, they learned how to enclose the mRNA inside microscopically small capsules to protect it from being destroyed by chemicals in our blood.
Already, mRNA vaccines are being tested for other infectious agents, such as Ebola, Zika virus, and influenza. Cancer cells make proteins that also can be targeted by mRNA vaccines: indeed, recent progress was reported with melanoma. And theoretically, mRNA technology could produce proteins missing in certain diseases, like cystic fibrosis.
