How to use particle effects in vertex animation?

So I have been using the vertex animation tool to export characters for use in a crowd (think big football type crowd). This all works pretty well and for my test I have 8 meshes which are all combined into one static mesh which the vertex animation is then applied to. So far so good.
But the problem comes when I want to apply particle effects to the scene. So far I’ve been making my particle effects and attaching them to sockets in a skeletal mesh. This works well but using a skeletal mesh for thousands of people in a crowd isn’t workable (hence the vertex animation). But with a vertex animation there is nothing to attach effects to? I can create sockets in the static mesh but these don’t move with the vertex animation.
So in short I’m stuck for ideas on how to progress.