mRNA vaccines are in the news after the U.S. Department of Health and Human Services cancelled $500 million in research grants for mRNA technology in August 2025, asserting, without sharing any evidence, that the vaccines are unsafe and ineffective. Use these talking points to answer your community members’ questions about mRNA vaccines, how they are developed, and the evidence for their safety and effectiveness.
What is an mRNA vaccine?
An mRNA vaccine is a type of vaccine that helps the body protect against diseases and severe illness. Scientists use several approaches or technologies to develop vaccines, and each approach creates a different vaccine type. All types of vaccines have the same goal of protecting people from disease, but they achieve it in different ways.
For example, most flu vaccines activate the body’s immune response against the flu virus by introducing either an inactive or weakened virus. In contrast, mRNA technology does not use any part of the virus. An mRNA vaccine introduces a short segment of mRNA that instructs the body to make a part of the virus that can activate the body’s immune response but is too small to cause the disease. The immune system then creates the tools to fight the virus whenever it encounters it. Once the mRNA delivers the instructions, the body breaks down the mRNA and it is completely cleared from the body, leaving behind only the ability for the body to fight a virus.
mRNA technology is the basis for the COVID-19 vaccine. Over 270 million people in the United States have received at least one dose of the COVID-19 vaccine. The vaccine’s widespread use during the pandemic and its continued use today demonstrate its safety.
Why do mRNA vaccines matter?
mRNA vaccines are effective at protecting against disease and are quicker to produce than other vaccine types. COVID-19 vaccines that use mRNA technology have helped prevent severe illness, hospitalization, and death for millions of people in the United States. Moderna and Pfizer COVID-19 vaccines that use mRNA technology are still used to protect against COVID-19 and its severe effects.
While some vaccine types, like the inactive vaccines used to protect against the flu, can take months to create, mRNA technology allows scientists and vaccine manufacturers to produce vaccines quickly. Respiratory diseases, like COVID-19, can change rapidly and have many variants. mRNA technology enables the development of updated vaccines responsive to those changes and helps prevent the COVID-19 variants most likely to be in circulation. The speed and safety of mRNA technology can be particularly helpful in responding quickly to the spread of pandemics.
Are mRNA vaccines safe?
Scientists have been researching mRNA vaccine development for decades. In 2018, the FDA approved the first drug made with mRNA technology. Years of mRNA research, testing, and approval processes supported the emergency development and use of the technology in the first COVID-19 vaccines in 2020. COVID-19 vaccines that use mRNA technology follow the same rigorous processes to ensure safety and efficacy as other vaccine types.
Billions of people worldwide have safely received at least one dose of the COVID-19 vaccine, which uses mRNA technology. Claims that mRNA vaccines are unsafe or cause permanent damage to the body have not been supported by evidence.
How will changes to mRNA funding impact communities?
Changes to mRNA funding could reduce the use of this effective technology to fight disease and illness, and pause or eliminate life-saving advancements for other chronic diseases and respiratory illnesses.
