Not long ago, measles was on the verge of eradication in the United States. But now, it is threatening to make a troubling comeback, with several cities and states, including Philadelphia, California, Washington, D.C. and Missouri,Ā clocking casesĀ in recent weeks. This has put public health officials and family physicians like me on high alert. We canāt let our guard down when it comes to educating patients, families and communities about the importance and effectiveness of immunizations for a wide range of diseases.