Allergy: Delayed Proof

Thousands of allergists and millions of patients have long "known" that hay-fever shots are beneficial. More cautious scientists have waited for reliable proof — which is hard to come by because 1) like all allergies, ragweed pollinosis is mixed up with emotional problems, and many patients think they feel better if they get any sort of treatment at all; and 2) symptoms vary as unpredictably as shifts in the wind.

At Massachusetts General Hospital, Dr. Francis C. Lowell and Dr. William Franklin designed a rigorous test to get around both difficulties. They kept a daily record of their patients' symptoms for an entire season, thus eliminating error from day-to-day variations. And they divided the patients into two groups, only one of which got injections containing ragweed extract in gradually increased amounts.

The comparison group received just as many injections of material that not only looked the same but raised an identical red wheal. The two different types of shots were labeled only with coded numbers; the doctors did not know which patient was getting which.

When the frost was on the pumpkin and the ragweed menace died, the code was broken and checked against the record of patients' complaints. Those who had had ragweed extract in their shots were found to have had only about half the comparison group's episodes of sneezing, nose running, eye watering and itching. It was official at last: those millions of injections were worth the cost and discomfort.