Allergies to peanuts are not rare. However, if relief in the form of an injection of epinephrine is not readily available, reactions can be so severe that death can result. Furthermore, the problem is compounded by the large number of prepared foods and meals that contain peanuts or peanut oil as an ingredient. The latest research in this field raises hope of a vaccine. It involves the oral administration of a gene that encodes Arah2, the peanut antigen that is responsible for inducing life-threatening symptoms to mice. Mice responded to the DNA vaccine by producing antibodies to Arah2, and they showed less severe symptoms in response to peanuts. Reference: Roy, K., Mao, H.-Q., Huang, S.-K. et al. 1999. Oral gene delivery with chitosan-DNA nanoparticles generates immunologic protection in a murine model of peanut allergy. Nature Med. 5(4):387-391. -- [log in to unmask] (Liza May)