U.S. Department of Health & Human Services

10/18/2021 | Press release | Archived content

Understanding mRNA COVID-19 Vaccines

COVID-19 mRNA Vaccines Have Been Rigorously Evaluated for Safety

mRNA vaccines have been held to the same rigorous safety and effectiveness standardsexternal icon as all other types of vaccines in the United States. The only COVID-19 vaccines the Food and Drug Administration (FDA) makes available for use in the United States (by approval or emergency use authorization) are those that meet these standards.

mRNA Vaccines Are Newly Available to the Public But Have Been Studied for Decades

Researchers have been studying and working with mRNA vaccines for decades. Interest has grown in these vaccines because they can be developed in a laboratory using readily available materials. This means vaccines can be developed and produced in large quantities faster than with other methods for making vaccines.

mRNA vaccines have been studied before for flu, Zika, rabies, and cytomegalovirus (CMV). As soon as the necessary information about the virus that causes COVID-19 was available, scientists began designing the mRNA instructions for cells to build the unique spike protein into an mRNA vaccine.

Future mRNA vaccine technology may allow for one vaccine to provide protection against multiple diseases, thus decreasing the number of shots needed for protection against common vaccine-preventable diseases.

Beyond vaccines, cancer research has used mRNA to trigger the immune system to target specific cancer cells.