How to reset Enderman drop height without using vines?

I have built the Enderman farm in the end, but I can't find vines in Minecraft 1.8.

Is there anything else that will reset the drop height like vines do?

There is no single block direct alternative that is safe (a Ladder isn't) and suited for Endermen (water).

Though, if a vine is absolutely unobtainable (Skyblock scenario without a Jungle sapling, for example), a safe and dry falling brake can be built with Ladders and Trapdoors. A trapdoor is 3/16th meter thick, so a raised trapdoor above a ladder should prevent falling entities from hitting the ladder (2/16th thick) and breaking legs.

Of course, you may need to decorate most of your chute's height with trapdoors, depending on mob falling patterns, so nothing diverges from the correct trajectory. You'll never require more than one trapdoor per 3 meters though, due to Endermen height.

Like this:

Cobwebs work, but they're kinda slow to get through. You can get them with shears or a silk touch enchanted sword. Good luck!