mRNA vaccines saved millions of lives during the COVID-19 pandemic. But U.S. Health Secretary Robert F. Kennedy Jr. has argued that they don’t work well, using this as the reason to cancel $500 million in government-funded research projects on new mRNA vaccines.
In a video posted on X, Kennedy said mRNA vaccines don’t do a good job preventing illnesses like COVID-19 and the flu. He said the government should instead focus on vaccines made with other methods.
Right now, COVID-19 is the only disease where mRNA vaccines have been used in the real world. Versions for other illnesses, like the flu, are still being developed. The scientists who made mRNA vaccines against COVID-19 possible were awarded a Nobel Prize in 2023.
Experts say Kennedy’s claim misrepresents how these vaccines work. mRNA vaccines do not fully block infections, but they are proven to protect against severe illness and death. Years of studies show their effectiveness against COVID-19.
Kennedy’s Claim vs. The Facts
KENNEDY: “As the pandemic showed us, mRNA vaccines don’t perform well against viruses that infect the upper respiratory tract.”
THE FACTS: This is not true. Research has repeatedly shown that vaccinated people do much better against COVID-19 than unvaccinated people. Studies also estimate that COVID-19 vaccines prevented millions of deaths worldwide.
Experts explain that while vaccines may not stop someone from getting a mild respiratory infection, they are very effective at preventing life-threatening illness. For example, an mRNA vaccine might not stop a COVID-19 infection in the nose or throat, but it can stop it from spreading to the lungs, where it could cause dangerous breathing problems.
Dr. Jake Scott, an infectious diseases expert at Stanford University, said:
“A vaccine cannot block a respiratory infection. That’s never been the standard. The goal is to prevent serious disease and death.”
Jeff Coller, a professor at Johns Hopkins University, agreed:
“Vaccinations reduce hospitalization and death. That’s proof they work.”
How mRNA Vaccines Work
Traditional vaccines usually require growing viruses or proteins in a lab, which takes a long time. mRNA vaccines are faster.
The “m” stands for “messenger.” The vaccine delivers instructions that tell the body to make a protein linked to the virus. The immune system then learns to recognize that protein and prepares to fight the real virus if it shows up.
Scott explained that these vaccines are not a “magic shield” that blocks a virus from entering. Instead, they prepare the body to fight once the virus is inside. That’s why COVID-19 infections may still happen, but vaccinated people are much less likely to end up in the hospital or die.
Evidence of Effectiveness
Since late 2020, many studies have shown strong results:
- A 2024 World Health Organization study found COVID-19 vaccines reduced deaths in Europe by at least 57%, saving 1.4 million lives.
- A 2022 study in Lancet Infectious Diseases estimated vaccines saved 19.8 million lives in their first year, including 4.2 million in India and 1.9 million in the U.S.
- A 2022 study in The New England Journal of Medicine found two mRNA vaccines were over 90% effective against COVID-19.
Operation Warp Speed, which sped up vaccine development and distribution, began under President Trump’s first administration.
Jeff Coller questioned why Trump is letting Kennedy cut funding for a technology that saved lives:
“Why allow RFK Jr. to undermine U.S. leadership in medical research?”
