Is venting a vertical waste line required?
No, vents are not required for any random vertical drop. Only plumbing fixtures require vents.

The main point of the vents in the drain system is to let the air enter the pipes at the spots where water enters it too. Without vents two things would happen: First - poor drainage, as both water and air are competing for space in, say, your sink drain. Second - low pressure in the pipes, created by water draining through one fixture, might suck in water from other fixture's trap. Which would let nasty sewer gases into living quarters.

As there's no new water entering at your vertical drop, a vent there won't do anything at all.