Dr. Peter Socrates Creticos, medical director of the Johns Hopkins Asthma and Allergy Center at the Johns Hopkins University School of Medicine and his team tested the DNA vaccine during two fall ragweed seasons in Baltimore.
The study was conducted on 25 volunteers with known allergies to ragweed of the ages 23-60 years. In the first year of the study, 14 people were given six weekly injections of the new vaccine before the ragweed season began. The remaining 11 received six weekly injections of a placebo.
The symptoms like sneezing, runny nose, watery eyes, and itching had reduced by 60% in people who received the vaccine. This relief was found to be steady even in the second year without the administration of the vaccine.
The Immune Tolerance Network funded this study. The National Institute of Allergy and Infectious Diseases and the National Institute of Diabetes and Digestive and Kidney Diseases are supporting this network.
Dynavax Technologies Corp. of Berkeley, Calif manufactures this DNA-based vaccine. It comprises a DNA sequence obtained from bacteria to shut down the T-helper (Th2) cells that trigger the body's inflammatory immune responses.
The study has been published in the October 5 issue of the New England Journal of Medicine.
Creticos said, ''I don't expect any serious long-term side effects because this vaccine restores normalcy. The vaccine is so specific, only targeting the ragweed allergy; there likely won't be any long-term adverse effects. In fact, the vaccine is so specific that people who were vaccinated and who also have grass allergies in the spring still experienced symptoms from that particular allergy. ''
He said, ''The next step for this vaccine is phase III trials, after which the vaccine could receive government approval if all goes well. It could potentially become commercially available a few years down the road.''