A new vaccine trial has been shown to protect people from ragweed pollen allergy for at least one year, according to an article in the New England Journal of Medicine. This experimental treatment requires just six injections, once a week. Current treatments require taking several medications each day throughout the ragweed season.
Allergic reactions to plant pollens are commonly known as Hay Fever

Trial researchers said further studies have to be carried out on a larger group of volunteers.

Study author, Dr. Peter Socrates Creticos, Johns Hopkins Asthma and Allergy Center, Baltimore, USA, and team, expanded on studies that had been carried out at the University of California, San Diego, which discovered that a bacterium DNA sequence shuts down Th2 (T-helper) cell activity – an inflammatory immune system response. Th2 is commonly found to be a major factor in human allergic responses.

To create a new vaccine the team attached the DNA sequence that halts Th2 response to a portion of the ragweed pollen. Th2 cells often overreact to ragweed pollen – the new vaccine stops the Th2 from overreacting.

The Th2 cells of people who are allergic to ragweed make the body produce igE, which causes the watery eyes and sneezing. The vaccine stops the Th2 cells from sending signals which make the body produce IgE when exposed to ragweed.

The problem with current allergy medications is that they are not well targeted. Current medications have side effects because they undermine the body’s immune system. This new vaccine is finely targeted – there are fewer side effects, say the researchers.

Twenty-five volunteers, aged 23-60, took part in this pilot trial,. All of them suffered from ragweed allergy. 14 were given six injections with the new vaccine, one each week consecutively. The other 11 were given a placebo injection, once a week for six weeks. Both groups started treatment before the ragweed season began.

Allergy symptoms during the ragweed season were 60% lower for the 14 who received the new vaccine, compared to the placebo group. Allergy relief continued during the next season, a year later (no additional treatment had been given).

Ragweed Allergy – Some Facts

The ragweed pollen season runs from August to November. Most areas in the USA see a peak in ragweed pollen levels in mid-September. Pollen counts tend to peak between 5am to 10am.

If you suffer from ragweed pollen allergy

— Try to stay indoors between 5am to 10am – unless there has been some heavy rain
— Try to keep the windows of your home and car closed
— Avoid using fans
— If your allergy is severe, remember that people can bring the pollen into the home on their clothing
— Pets can bring the pollen in
— Avoid drying your clothes by hanging them outside


— eye irritation
— inflamed, itchy nose and throat
— puffy eyes
— runny nose
— sneezing
— stuffy nose
If your allergy is more severe, symptoms may also include the following:
asthma attacks
— chronic sinusitis
— impaired sleep

Immunotherapy with a Ragweed-Toll-Like Receptor 9 Agonist Vaccine for Allergic Rhinitis
Peter S. Creticos, M.D., John T. Schroeder, Ph.D., Robert G. Hamilton, Ph.D., Susan L. Balcer-Whaley, M.P.H., Arouna P. Khattignavong, M.D., Robert Lindblad, M.D., Henry Li, M.D., Ph.D., Robert Coffman, Ph.D., Vicki Seyfert, Ph.D., Joseph J. Eiden, M.D., Ph.D., David Broide, M.B., Ch.B., and the Immune Tolerance Network Group
NEJM Volume 355:1445-1455 – October 5, 2006 – Number 14
Click here to see abstract online

Written by: Christian Nordqvist
Editor: Medical News Today