This is a class of vaccines that utilizes a piece of genetic information from a specific pathogen to produce an immune response in the body and prevent disease.
Deeper dive
Most conventional vaccines contain either an inactivated pathogen or the protein made by that pathogen called an antigen.
Genetic engineering has enabled scientists to develop a new way to design, test, and manufacture vaccines. The method involves taking a piece of a pathogen’s genetic material to trigger the body’s immune response.
This is what has been used with some COVID-19 vaccines. Pfizer and Moderna’s vaccines utilize RNA from the SARS-CoV-2 virus [the virus that causes COVID-19]. The RNA is injected into the body to trigger the production of SARS-CoV-2 antigens. Antigens are molecules that spur the body’s immune system to recognize a biological intruder.
Once the immune system “sees” the SARS-CoV-2 antigen, the body produces antibody proteins. If the whole SARS-CoV-2 virus should enter the body, there are now existing antibodies to immediately mark the virus as an intruder, enabling the immune system to quickly mount a defense and thwart disease.
RNA vaccines aren’t made of the pathogen itself, so they aren’t infectious; they tend to be well-tolerated by the body, and they can be produced more rapidly than conventional vaccines.
Using genetic engineering also enables scientists to quickly update vaccines. For example, both Moderna and Pfizer have developed a booster vaccine to protect against the latest omicron variant of SARS-CoV-2, months after the variant emerged.
To read more about RNA vaccines in greater detail, see this University of Cambridge link.