Rab reached out and grabbed the Healer's robes. He watched the worm struggle, then shook him to make him stop. "Well it is possible! Not only do I have it, so does Lisa, and Bellatrix, and Rodolphus! He has it worst of all."
He snarled. "So... here is what you will do. You will take a sample of my blood or whatever you need. You go back to your lab... find out why this has happened... then you will develop another vaccine to give to everyone here. And if you do not... I will let Lisa deal with you directly. Or perhaps... I will give you to Bellatrix to deal with."