It looks like you asked Mr. Google and got your answer. 

IDX covers a lot of types of feeds including VOW feeds which include data every feed doesn't.... sales history, price reductions, sold data etc.  Our MLS allows us to opt out and most agents/sellers do because they want their house dropped when it's sold from displays. The sold data remains on the MLS, but not on feeds.

I have no idea what a vow feed is so you are already much smarter than I am.

I say no. I don't think that any uses VOW feeds anymore.

@dario

I like your question Peter Mohylsky. BRIX REALTY because I don't have a clue and also I do not know the term vow feed. 🤥

Have used IDX for many years.  Never a vow. Can't help ya.

Here you go...remember this?

https://activerain.com/blogsview/5333800/what-is-the-difference-between-idx-and-vow-

I was thinking there were only IDX feeds out there, but could be wrong.

I am with Bob Crane on this one. Parked and reading!

I know a bit more now than I did before reading the answers here.

I think the IDX is on our website (essentially a VOW)??? Not 100% sure but, I use IDX and LOVE my new site by @Charra!

In 2003 IDX was minimalist - active listings only etc, whereas VOWs have always included all MLS data.
However, IDX policies have developed enormously and these days IDX feeds generally include nearly all MLS fields and listing status (e.g. coming-soon, open house data, many years of sold data, etc).

So, from a marketing perspective we rarely see any difference. 

IDX feeds still don't include sensitive data such as broker comments etc. 
And, in non-disclosure states, a VOW may be the only way to get hold of sold data.

Hope this helps!