Chicken Pox Conundrum

Should all children be vaccinated? The government weighs the risks of preventing a mild disease.

Since chicken pox is just an itchy nuisance for most kids rather than a real danger, American health officials have been in no great hurry to come up with a vaccine. A shot was developed in Japan and has been tested in the U.S. for a decade, amid criticism that the effort was not worth the expense. Now, at long last, the Centers for Disease Control and Prevention (CDC) is preparing to decide whether all kids should be protected against the pox.

The vaccine would have clear virtues. Despite its less-than-fearsome reputation, chicken pox causes up to 100 deaths a year,...