Plenty of flosses are available without pfas. The flat glide / smooth floss and potentially flavors (unknown - not required to disclose) are the ones with pfas. Wax coated unflavored floss does not use pfas.

Unfortunately, the article [0] states that "flat tape" floss was used as the delivery method. And this is the form of those smooth/glide pfas flosses. Likely the pfas was used as a functional group to bond the vaccine coated particles to the floss.

[0] https://www.nature.com/articles/s41551-025-01451-3