Ask open-ended questions recursively. People often have a story or experience at the root of their beliefs. Uncovering that root (with your questions) also give

Ask open-ended questions recursively. People often have a story or experience at the root of their beliefs. Uncovering that root (with your questions) also gives the anti-vaxxer an oppprtunity to ask new questions about why they believe what they believe. Generally, we need new questions to arrive at new answers.