Skip to main content
Monday, November 9, 2026Nov 9

What to know about mRNA vaccines

Health and Human Services Secretary Robert F. Kennedy Jr. speaks as President Donald Trump listens at an event to promote his proposal to improve Americans' access to their medical records in the East Room of the White House, Wednesday, July 30, 2025, in Washington. (AP Photo/Mark Schiefelbein)
Health and Human Services Secretary Robert F. Kennedy Jr. speaks as President Donald Trump listens at an event to promote his proposal to improve Americans' access to their medical records in the East Room of the White House, Wednesday, July 30, 2025, in Washington. (AP Photo/Mark Schiefelbein) Health and Human Services Secretary Robert F. Kennedy Jr. speaks as President Donald Trump listens at an event to promote his proposal to improve Americans' access to their medical records in the East Room of the White House, Wednesday, July 30, 2025, in Washington. (AP Photo/Mark Schiefelbein)


WASHINGTON (AP) — So-called mRNA vaccines saved millions of lives during the COVID-19 pandemic — and now scientists are using that Nobel Prize-winning technology to try to develop vaccines and treatments against a long list of diseases including cancer and cystic fibrosis.

But this week, U.S. Health Secretary Robert F. Kennedy Jr., a longtime vaccine critic, canceled $500 million in government-funded research projects to create new mRNA vaccines against respiratory illnesses that might trigger another health emergency.

That dismays infectious disease experts who note that mRNA allows faster production of shots than older vaccine-production methods, buying precious time if another pandemic were to emerge.

Using older technology to target a pandemic flu strain would take 18 months to “make enough vaccine to vaccinate only about one-fourth of the world,” said Michael Osterholm of the University of Minnesota, an expert on pandemic preparation. But using mRNA technology “could change that dramatically, such that by the end of the first year, we could vaccinate the world.”