Difference between MVVM and MVA (Model-View-Adapter)

What is the difference between MVVM and MVA (Model-View-Adapter)?

As long as in both patterns:

1. The VM and Adapter mediate between View and Model.
2. There could be more than one VM and Adapter participated in these patters for the same model.
3. The model interacts directly with VM and Adapter.

The only thing that comes to my mind is that in MVVM, VM will not receive any notifications from Model, but in MVA the adapter receives notifications from Model!

So how the difference of these patterns can be explained?