Every state requires children to be vaccinated before they attend school, but all states also allow for exemptions. Some states have moved to tighten exemptions, including California, where vaccination rates are now at their highest level in more than 15 years. Vermont has also made it tougher to opt out of vaccines. We spoke to parents there on both sides of the issue - those who feel it’s their right not to vaccinate, and to a mom whose daughter was battling cancer and couldn’t be vaccinated. She needed others around her to have their immunizations against diseases such as measles and chicken pox, to reduce the risk of illness and help protect her.