Seventy-five percent of Americans who are allergic to pollen-producing plants are actually allergic to ragweed whose season runs from mid-August to October.
Ragweed grows throughout the United States but mostly in the eastern states and in the Midwest and causes a significant number of fall allergy symptoms such as runny or stuffy noses, sneezing, and itchy eyes, nose and throat.
The symptoms are usually dealt with by antihistamines that brings relief most of the time but if antihistamines fail, patients are referred to the next line of treatment - allergy shots.
Although highly effective, allergy shots have a few drawbacks. Patients need to go in every week to receive the shots for 6 to 18 months in order to reach up for the maximum effect and build their immune system. They additionally have to wait for at least 30 minutes at the doctor's office in case adverse reactions occur.
A new wave of investigational vaccines: Pollinex Quattro and Tolamba
A new wave of investigational vaccines could be just the thing allergy sufferers need.
What would do best and they would hope for is fewer injections less often, offering longer-lasting relief with no side effects. Such vaccine may be available in the years to come.
Two different teams have separately been working on such vaccines.
Researchers from the Lovelace Scientific Resources in Austin, Texas have presented four injections of an investigational ragweed vaccine, called Pollinex Quattro, which proved to be safe and effective.
Another team from the Johns Hopkins Asthma and Allergy Center in Baltimore tested another ragweed vaccine, called Tolamba, for a concise six-week period in the six-injection regimen. Tolamba proved to be effective at shutting off seasonal symptoms for at least the two seasons the patients have been followed.
Both of these investigational vaccines have been shown to be more effective in fewer doses and to reduce the incidence of adverse reactions.
How do allergy symptoms appear?
People who suffer from allergies produce an antibody called immunoglobulin E. When in contact to an allergen, ragweed for example, this antibody sets off a cascade of chemicals to fight the perceived allergen. This chemical response triggers the allergic symptoms that trouble and annoy allergy sufferers so much. Besides immunoglobulin E, there is another antibody in blood, called immunoglobulin G, which fights infections.
What the trials showed
The Texas researchers studied different doses of a ragweed extract and their effect on antibodies in the bloodstream. The study showed that the G antibodies increased proportionate to the strength of the injections given. The weaker injection had less of an effect, the medium had more, and the highest dose had the highest effect on the G antibodies.
When it comes to Tolamba vaccine, a large, multi-center trial managed to replicate findings of the Tolamba pilot study and additional studies are ongoing.
Overcoming hurdles on the road
However, these improved allergy shots won't be available on the market right away, and definitely not this ragweed season. First it needs to be proven that these approaches are safe and effective especially now that clinical studies on Pollinex Quattro vaccine have been put on hold by the FDA due to a report of a rare adverse event.
So, until vaccine makers clear the hurdles and offer allergy patients improved treatments, the ragweed sufferers should try to minimize their exposure by keeping windows in their cars and homes closed to prevent pollen from entering as well as shower after going outdoors as pollen collects on hair and skin.