Define safe. I agree with those who have said that the main risk is disturbing the clot(s) and winding up with the excruciating experience of dry socket. Vaping and smoking are a double whammy, because there's not only the vacuum creating by suction that can disturb the clot, but nicotine can help break it down as well. Did they tell you to avoid straws and the like for a certain period? That would be how long you need to avoid sucking on things.
If you really can't make it without the nicotine, try a patch or a tiny drop or so of ejuice on your tongue. Nicotine isn't great, but it's better than nicotine and suction.
ETA. I'm sorry to say that I've just looked up how long you should avoid suction and the general advice seems to be one week. I don't know if I could hold out that long (well, yes I do know actually - I didn't), but the longer the better.