Rather than oohing and aahing at the beautiful autumn foliage, the 36 million Americans with seasonal allergies spend August through October ahh-chooing ! The hallmark symptoms of hay fever —sneezing, runny nose, and swollen, watery eyes—are often due to ragweed, a plant that produces one billion pollen grains per season.

Allergy sufferers rely on various pills and sprays to minimize their symptoms. Some patients receive longer-term relief from allergen immunotherapy, a series of shots given weekly over months or years to build up tolerance to symptom-producing allergens. Drawbacks to immunotherapy include a risk of allergic reactions and a demanding treatment schedule.

In an effort to design allergy treatments that are simple to deliver and pose minimal risks, Johns Hopkins’ researchers tested a new vaccine against ragweed. In this small study in the October 5, 2006 New England Journal of Medicine , allergy sufferers given the vaccine reported significantly fewer symptoms during the next two ragweed seasons than those given placebo.

About the Study

Researchers at Johns Hopkins Asthma and Allergy Center enrolled 25 patients, ages 23-60, with ragweed-induced seasonal allergies. Based on random assignment, half of the patients received the ragweed vaccine and the other half, a placebo vaccine. Both the vaccine and placebo were given as six, once-weekly injections, before the 2001 ragweed season. During the 2001 and 2002 ragweed seasons, researchers compared symptoms, immune responses, and side effects between the two groups of allergy sufferers.

During the 2001 season, the vaccine group had significant improvements in total symptoms, nasal symptoms, and quality of life scores, compared with the placebo group. The reduction in total and nasal symptoms persisted through the 2002 season. There was no difference between the groups, though, in nasal vascular permeability , a measure of inflammation that is usually reduced with successful allergy treatment.

This study is limited by its small size and by the vaccine’s lack of effect on nasal vascular permeability. In addition, long-term safety cannot be determined from a two-year study.

How Does This Affect You?

Don’t run to your allergist for the ragweed vaccine yet. The symptom relief reported in the vaccine group is intriguing and highly promising, but this study’s results are most useful as a stepping stone for further research. While the average sniffling, sneezing allergy sufferer may not be interested in laboratory findings, the fact that nasal vascular permeability—which was the study’s main outcome measure—was not affected is of interest to scientists. It is unclear exactly how this vaccine works and if it will consistently and safely provide long-term relief.

If you suffer from seasonal allergies, the American Academy of Allergy, Asthma, and Immunology recommends the following steps to manage the allergy season:

  • In your car and at home, keep windows closed to prevent pollen from drifting in. Use air conditioning, which cleans, cools, and dries the air.
  • If possible, minimize outdoor activity between 10:00 am-4:00 pm when pollen counts are highest.
  • Take a shower after being outside to remove any pollen that collected on your body.
  • Don’t hang sheets or clothing outside to dry. Pollen can collect on them.
  • Minimize exposure to other known allergens during ragweed season.
  • Get up-to-date pollen information for your area from the National Allergy Bureau.
  • Ask your doctor which medications may be appropriate for you.