FDA approves Moderna's mRNA flu vaccine after initial pushback

The U.S. Food and Drug Administration has approved a new seasonal flu vaccine from Moderna that uses mRNA technology, the drugmaker announced Wednesday.

mFLUSIVA, approved for adults ages 50 and older, is the first influenza vaccine using mRNA technology to receive FDA approval.

"This approval also reflects the ongoing potential of our mRNA platform to help address important public health challenges through continued scientific innovation. We are grateful to the clinical trial participants, investigators, regulators and Moderna teams whose contributions made this milestone possible," Moderna said in a statement.

It comes after the FDA had earlier this year said it would refuse to consider Moderna' application, but later reversed course and stated it would allow the vaccine to proceed to review.

The dispute had centered on a 40,000-person clinical trial that found Moderna's new vaccine was more effective in adults aged 50 and older than one of the standard flu shots used today.

This is a developing story and will be updated.