While the vaccines for Covid-19 seem to have been created in record time, the technology making them possible has been decades in development. The two vaccine candidates produced by Pfizer/BioNTech and Moderna are unlike any other vaccine that’s come before. Should they achieve commercial success, it could usher in a new era of medical science — not just for vaccines, but for cancer treatments, blood disorders, and gene therapy.
The two new vaccines are the first ever to use mRNA, which stands for “messenger RNA,” to generate immunity. Historically, vaccines have used dead or weakened viruses to imitate an infection, spurring the body to make antibodies against that virus without danger of getting sick. Measles, polio, and some seasonal flu shots are examples of vaccines made with whole virus particles.
Other vaccines use only certain fragments of the virus, called antigens, that provoke an immune response. To make this type of vaccine, the genetic code for the desired viral antigen molecule is put into yeast or bacteria cells. These microbes can be grown rapidly and inexpensively, and they can churn... see more