"are in interaction" is correct and usable in written English.
You can use it to describe two things or people who are having an effect on one another. For example, "The supervisor and employees are in interaction, making sure everyone understands their roles and responsibilities."
Those events that are in interaction with vulnerabilities can lead to a disaster [1].
The civilization era are in interaction, but tend to neglect the moslem city image.
High fluoride levels indicate that these waters are in interaction with subsurface mica and apatite-bearing rocks.
This framework sees human behaviour, including migration and transnational engagement, as the result of the interaction between individuals' agency, desires and capacities, which are in interaction with the structural environment.
It is characterised by the use of interaction graphs (graphs with interaction functions on their edges) to represent the system as composed of processes, each involving several entities distributed in space that are in interaction with each other.
Additionally, the lateral position and riding speed of bicyclists that are in interaction with buses are compared with the behaviour of bicyclists that are not in interaction with buses.
Consider that there are in-person interactions that you never see, or kind, forgiving letters.
As the film gathers pace, it is as if the whole room is in interaction with the moving images.
Just like other visual cultural elements, poster as well is in interaction with the society.
In the graph, an edge was assigned for each pair of proteins if they were in interaction with each other.
These interactions are in-line with interactions mentioned in the preceding paragraph.
