TRENTON, N.J. -- For decades, seasonal allergy sufferers had two therapy options to ease the misery of hay fever. They could swallow pills or squirt nasal sprays every day for brief reprieves from the sneezing and itchy eyes. Or they could get allergy shots for years.

Now patients can try another type of therapy to train their immune system, new once-a-day tablets that dissolve quickly under the tongue and steadily raise tolerance to grass or ragweed pollen.

The downside: The pills, from drugmakers Merck and Stallergenes, must be started a few months before the grass or ragweed pollen season. That means it's too late for people with grass allergies, but the time is now for ragweed allergy sufferers.

Meanwhile, new treatments for other allergies, including to peanuts and eggs, are in testing.