Nose-drop vaccine provides protection.Most vaccines rev up the antibodies that circulate in the blood. Only a few vaccines stimulate an immune response immune response n. An integrated bodily response to an antigen, especially one mediated by lymphocytes and involving recognition of antigens by specific antibodies or previously sensitized lymphocytes. in the body's mucous membranes Mucous membranes The inner tissue that covers or lines body cavities or canals open to the outside, such as nose and mouth. These membranes secrete mucus and absorb water and salts. Mentioned in: Leprosy, Pulmonary Fibrosis, Topical Anesthesia . Now, researchers report, they have developed a vaccine approach that does both. Administered as drops in the nose, a vaccine made by the technique has immunized mice against Borrelia burgdorferi, the tick-borne bacterium that causes Lyme disease. The immunity lasted for up to a year, says Solomon Langermann of MedImmune, a biotech company in Gaithersburg, Md. Researchers have not yet tested this vaccine on humans. Because B. burgdorferi does not enter mucosal tissue, the antibodies in the mice's blood protect them from the bacterium, Langerman and his colleagues report in the Dec. 8 NATURE. However, they note, the vaccine did increase the number of antibodies in the mucosae lining the animals' respiratory, gastrointestinal, urinary, and genital tracts. Many bacteria and viruses, including those that cause pneumonia and sexually transmitted diseases Sexually transmitted diseases Infections that are acquired and transmitted by sexual contact. Although virtually any infection may be transmitted during intimate contact, the term sexually transmitted disease is restricted to conditions that are largely , enter the body through mucous membranes. Vaccines that trigger antibodies present in mucosal secretions could presumably pre·sum·a·ble adj. That can be presumed or taken for granted; reasonable as a supposition: presumable causes of the disaster. block these infections, Langermann contends. He and his colleagues are developing a nose-drop vaccine against pneumonia and urinary infections and will investigate the possibility of making a similar vaccine against gastrointestinal infections, he says. To produce the Lyme vaccine, the researchers genetically engineered a strain of Calmette-Guerin bacillus bacillus (bəsĭl`əs), any rod-shaped bacterium or, more particularly, a rod-shaped bacterium of the genus Bacillus. Some bacterium in the genus cause disease, for example B. (BCG BCG bacille Calmette-Guérin. BCG abbr. 1. bacillus Calmette-Guérin 2. ballistocardiogram BCG, n.pr See bacille Calmette-Guórin. ) to make a B. burgdorferi protein that stimulated production of antibodies against the bacterium. Physicians outside the United States use BCG, a weakened form of a bacterium that infects cows, in the tuberculosis vaccine (SN: 6/18/94, p.393). Other vaccines against human Lyme disease are available, but only for experimental purposes. |
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