New hope on asthma

A VACCINE made with synthetic bacterial DNA has been shown to stop asthma in its tracks and reverse lung damage.

Current medications only control symptoms. Californian scientists say the new vaccine, still in early development, is the first to halt the disease and allow healing. The vaccine works by stimulating a broad immunological response. Successful in animal studies, it is now being studied in humans and tested against other allergic diseases. Preliminary trials show it provides significant relief for hay fever sufferers, and trials are planned for asthma patients. Its ability to reverse lung damage has been demonstrated in experiments in monkeys and mice. “It may turn out to be a breakthrough; it may not,” said Dr Marshall Plaut, of the National Institute of Allergy and Infectious Diseases. “But certainly there’s some very promising data that has emerged in the mouse and primate studies, and impressive preliminary data in humans.” The medication, called ISS, works because the body recognises the bacterial DNA as foreign and beefs up the immune system, tipping it away from allergic reactions such as asthma and hay fever. In the American Journal of Respiratory and Critical Care Medicine, cell biologist Charles Plopper of the University of California said four asthmatic rhesus monkeys given ISS had clear lungs after 44 weeks. “Most of us were pretty stunned that it was as successful as it was,” he said. “We didn’t see any side effects. “We didn’t see anything that appeared to us to be abnormal, except they were no longer asthmatic.” A similar reversal of asthma-induced lung damage in mice given ISS was reported in the Journal of Immunology. The scientists say it may be possible to develop vaccines to treat many common diseases by attaching allergic or inflammatory molecules to the DNA sequence, triggering a beneficial immune response. A hay fever trial to determine the drug’s efficacy is being planned. Dr Peter Creticos, of Johns Hopkins Medical School, is planning to begin trials with ISS in asthma patients. Dr David H. Broide, senior author of the mouse paper, said: “Of all the compounds that are out there, this is the most promising that I’ve seen. “But it still needs to be studied in larger numbers of patients to be sure that this is going to pan out and that it has a good safety profile,” he said. Other asthma vaccines are in various stages of development elsewhere.(Source: American Journal of Respiratory and Critical Care Medicine, Herald Sun Health, December 2004)