Gamerule to turn off Villager Zombification

This is an issue I've had with mapmaking a lot recently. I cannot have a location with both zombies and villagers because they always zombify, and it's infuriating. For example, I have an NPC villager that trades the player a very very important item, but there's a zombie battle about 30 blocks away with just a singular zombie. Of course, that zombie decides to walk straight up to the most important NPC in the world and zombify it. There's no NBT data I can edit to fix this, nothing, I just have to build around it which ruins the look of the build.