Providers could begin to share immunization data with a state registry as a way of demonstrating how health information exchange could work in the next iteration of meaningful use criteria, health IT experts suggested this week. That would an example of how to begin to realize the goals set out in a December report from the President's Council of Advisors on Science and Technology (PCAST) , in line with ideas the Office of the National Coordinator for Health IT is seeking to foster more complex data exchange. ONC held a two-day hearing Feb. 15 and 16 to gather information for how to put the PCAST goals into practice. However, despite the recognized need for more robust health information exchange, providers and vendors balked during the hearing at the report's recommendations if it meant they would have to redo existing systems. Others proposed that middleware could be bolted on to existing systems to accomplish the reuse of data that PCAST envisions.