Probably because the HHS secretary is vehemently opposed to lipid nanoparticles.
https://www.axios.com/2025/04/18/rfk-jrs-potential-future-ta...
https://kffhealthnews.org/news/article/nih-grants-mrna-vacci...
> National Institutes of Health officials have urged scientists to remove all references to mRNA vaccine technology from their grant applications, two researchers said, in a move that signaled the agency might abandon a promising field of medical research.
They've been working on this for years. It's not anything to do with the current administration.