How to child proof floor vents?

Cass • •Mrs. 💍 •27💕• 2/20/2011👦🏻, 12/14/17👧🏼, 1/6/20 👶🏼

Anyone know how to child proof floor vents? They are already screwed down as that’s how they come, but the problem is she has fallen and got her finger stuck in the hole and bent it forwards enough that her little finger is swollen, and cut on both sides. She is just about 18 months, and there’s 2 vents in her playing area