VANCOUVER -- ID Biomedical announced today that it has confirmed that nasal Proteosome-based vaccines protect against pneumonic Plague caused by lethal aerosol infection with virulent Plague bacteria in a mouse model of airborne dissemination.
In a series of experiments performed by the US Army Medical and Materiel Command (USAMRMC) at Fort Detrick in Frederick, Md., in collaboration with ID Biomedical, mice nasally immunized with Plague antigen formulated with the Proteosome technology were completely protected against lethality even when the dose of Plague antigen was ten-fold lower than ever previously given nasally. Mice were 100 percent protected when challenged at either early or later times after only two nasal immunizations of the Proteosome Plague vaccine. In marked contrast, none of the control mice given nasal solution without vaccine antigen survived the lethal aerosol challenge with virulent Plague bacteria.
High anti-Plague IgG antibodies in serum and high anti-Plague IgA levels in collected lung secretions were found at both early and late time points post-immunization with the nasal Proteosome-based Plague vaccine. These levels were 10 to 200 times the low levels of these antibodies detected when the Plague antigen was given nasally without the Proteosome-based technology.
These data are to be presented in part today in Arlington, Va. by George Lowell, MD, chief scientific officer of ID Biomedical at the sixth annual Conference on Vaccine Research, sponsored by the National Foundation for Infectious Diseases and in part on May 20, 2003 in Washington, D.C. by Dr. Jefferey Adamovicz, LTC U.S. Army, at the American Society for Microbiology 103rd general meeting.
"These strong and protective serum IgG and lung IgA antibody results confirm the value of Proteosome-based adjuvants for nasal vaccines against bioterror agents, particularly since injected immunizations with the Plague antigen plus Alum (an FDA-approved adjuvant) did not elicit any detectable local IgA in collected lung fluids. It is important to note that the lung is the most important organ to protect against airborne biothreat attacks," stated Lowell. "The potential for application of the Proteosome technology to develop novel, safe and highly effective nasal vaccines against multiple bioterror agents, including Pneumonic Plague, warrants serious consideration, especially given that other Proteosome-based vaccines have been safely administered to several hundred people in human clinical trials."
The Plague, also known as "the Black Death," is caused by Yersinia pestis bacteria. In past centuries, there have been over 150 recorded epidemics and pandemics of the Plague, including a pandemic that killed about one-third of the population of Europe and England. Plague pneumonia is highly contagious because large numbers of Plague bacteria can rapidly spread person-to-person through coughing and initial symptoms are similar to the flu. There is no licensed vaccine against the pneumonic form of Plague. The injected formalin-killed whole cell vaccine made many years ago does not protect against inhaled exposure to Plague bacteria and has been withdrawn from the market.
Source: ID Biomedical Corporation