Poss to take advantage of super-low rate?

Hi
sure I'm not the only one who's thought about this...

I recently took a 5-yr fix @2.99, but am wondering if it would be possible to take advantage of the current much lower rates in any way to help effectively reduce my mortgage rate.

All thoughts welcome, hopefully it's not just a dead-end idea.

I have over 55% equity if thats relevant?

Thanks