Yes!
The best option to use vMix with Loola is via Loola's RTMP Mode and vMix "Stream" option.

First, select RTMP mode in Loola to find you RTMP Key and URL:

Open the stream settings in vMix:

Copy and paste the RTMP URL and Key from the Loola Studio to vMix:

Configure the Quality/Encoder settings:

See recommended platform encoder settings here:
​https://support.loola.tv/en/articles/3284585-rtmp-encoder-settings

Click the Stream button in vMix to start the preview in Loola:

Once you can see the vMix video preview in Loola, you can select your destinations in Loola and click Go Live: