Families who move across state lines lose their vaccine records

When a military family, immigrant family, or any household relocates from one US state to another, their children's vaccination records frequently do not follow them. The new state's pediatrician queries their local IIS and sees a blank slate. The parent may have a crumpled paper card with some dates, but it may be incomplete or illegible. So what? The new provider must either accept incomplete documentation and guess, or restart the entire vaccine series from scratch. So what? Restarting means the child endures unnecessary injections, the provider wastes doses from a constrained supply, and the family incurs additional visit costs. So what? For families who move frequently (military, seasonal workers, families in unstable housing), this compounds -- each move resets the clock, and children fall further behind on the recommended schedule. So what? These are precisely the populations already at highest risk for under-vaccination, and the system's inability to track them makes the disparity worse. Why does this persist? The 64 jurisdictional IIS systems were built independently with no federal mandate for interoperability. Cross-jurisdictional data exchange requires bilateral agreements between states, and most states have not signed them. The CDC's IZ Gateway is voluntary, and adoption is slow.