Double digit increases in health care costs are posing a significant budget challenge to many school boards across the state. Local school officials are also feeling pressure from Governor Peter Shumlin, who is urging them to cap their spending increases to two percent or less. State health officials say turnout was strong at a series of clinics held yesterday to vaccinate Vermonters for Pertussis, commonly known as whooping cough. The clinics are an effort to stop the spread of the illness which officials say has reached epidemic levels in Vermont. The FBI has ruled out serial killer Israel Keyes in the disappearance of Vermont teenager Brianna Maitland in 2004.