Semi-supervised learning algorithms for multibox/priorbox detection in images

I've read lots of papers on query strategies like BADGE, SCALAR, BatchBALD etc, but they all seem to be for situations where there is a single label to give an image (is this a cat, dog or horse), but for tasks like vehicle camera images (using models like YOLO) a single image may have multiple labels in multiple classes.

In this case, what techniques are available for addressing Semi-Supervised Learning?