This shouldn’t be a philosophical debate. It’s a misunderstanding of how infectious disease works. Vaccines aren’t perfect. The measles vaccine is 97% effective with two doses, not 100%, so some vaccinated people remain vulnerable. More importantly, some people can’t be vaccinated at all: infants under 12 months, immunocompromised patients, people with anaphylactic reactions to vaccine components. They depend on the rest of us not spreading a highly contagious virus to them. Measles has an R0 of 12-18, meaning each infected person spreads it to 12-18 others in an unvaccinated population. The virus can linger in the air for two hours after an infected person leaves a room. At that level of contagion, you need 92-95% vaccine coverage to stop community transmission. When coverage drops, outbreaks happen, and the people who pay the price are often those who had no choice in the matter. “My body, my choice” makes sense for decisions that affect only your body. Transmissible disease isn’t that. Your choice not to vaccinate can put a 6-month-old in the hospital or kill an immunocompromised kid who couldn’t get the shot. The question isn’t “why does it matter if I take it.” The question is whether your comfort with risk should override someone else’s right not to get infected by you.