Comprehensive review affirms that COVID mRNA vaccines are safe, effective

News brief

A comprehensive review of the billions of COVID-19 vaccine doses made with mRNA technology shows that these vaccines are safe and effective.

Vaccine skepticism increased during the COVID-19 pandemic, with some mistrust specifically directed at mRNA vaccines. The global health emergency marked the first time mRNA technology was approved for large-scale use, and people questioned its safety and trustworthiness.

About a dozen syringes of the COVID-19 vaccine lay on a table surrounded by paperwork. — Credit: Mecklenburg County / Flickr

But the new study, published yesterday in The Lancet, reaffirms that serious adverse events, such as anaphylaxis (a severe allergic reaction) or myocarditis (inflammation of heart muscle), are rare after receiving an mRNA COVID shot. Researchers found that the odds of such medical emergencies were "consistently outweighed by the substantial protection" the vaccines provide against severe disease, hospitalization, and death. That includes among people who are pregnant or immunocompromised.

Because mRNA vaccines are faster to produce and easier to customize, the findings have promising implications for influenza, respiratory syncytial virus (RSV), and other infectious diseases, as well as for personalized cancer vaccines and other RNA-based therapeutics.

mRNA vaccines are expensive, harder to store

Though mRNA technology has the potential to transform vaccine development, the researchers note that considerable challenges persist.

For one, while the COVID mRNA vaccines are good at generating short-term antibody and memory B-cell responses, they are less effective at producing long-lived plasma cells in bone marrow.

Global access remains a challenge. These vaccines require ultra-cold storage, which complicates distribution to low-resource areas. High costs also limit access: October 2025 data show that mRNA vaccines, including mResvia for RSV, cost $85 to $290 per dose.

To realize mRNA vaccines' full public-health potential that's beyond pandemic use, the authors say that these challenges must be addressed.

"mRNA vaccines have already changed how we respond to global health threats,” said senior author Manish Sadarangani, DPhil, in a University of British Columbia news release. "With sustained innovation, strong safety monitoring, and a commitment to equitable access, they can play a major role in preventing disease and improving health."

Air Force trainee in San Antonio, Texas, died from flu

News brief

Liz Szabo, MA

Troops march in formation at Lackland Air Force Base in Texas. — RonBailey / iStock

The cause of death for an Air Force trainee who died last month at Lackland Air Force Base in San Antonio was influenza, according to Rep. Joaquin Castro, a Texas Democrat.

Keon Talik McDaniel, 25, died June 16, according to his obituary.

Influenza swept the air force base in June, one month after Defense Secretary Pete Hegseth made the flu shots voluntary, rather than mandatory, for American troops.

Nearly 300 troops have been sickened by influenza, Castro said in a press release.

“The Air Force confirmed that trainee Keon McDaniel died from the flu during the outbreak at Lackland Air Force Base in San Antonio,” Castro said. “This is a tragedy that could have been prevented were it not for the reckless actions of Secretary Hegseth.”

Race to vaccinate

The military reversed its flu vaccine policy, once again making it mandatory, then raced to vaccinate troops before the vaccines expired June 30, according to reporting by The Guardian.

Castro and Rep. Chrissy Houlahan, a Pennsylvania Democrat, co-sponsored an amendment to the National Defense Authorization Act (NDAA) to require military servicemembers to be vaccinated against influenza.

“I will continue to push for the Pentagon to fully restore its vaccine mandate and protect lives,” Castro said in the statement. “Our military must be guided by science, not politics.”

Influenza can be extremely contagious in confined settings, and spreads easily among people who live in group housing, such as military barracks, dormitories, and homeless shelters.

The influenza vaccine provides "significant protection against serious illness, hospitalization and death,” said Michael T. Osterholm, PhD, MPH, director of the Center for Infectious Disease Research and Policy at the University of Minnesota (CIDRAP), which publishes CIDRAP News.