Studies from Harvard University yield new data on Bacillus calmette-guerin vaccines
2007 APR 2 -- Scientists discuss in "Drying a tuberculosis vaccine without freezing" new findings in Bacillus calmette-guerin. "With the increasing incidence of tuberculosis and drug resistant disease in developing countries due to HIV/AIDS, there is a need for vaccines that are more effective than the present bacillus Calmette-Guérin (BCG) vaccine. We demonstrate that BCG vaccine can be dried without traditional freezing and maintained with remarkable refrigerated and room-temperature stability for months through spray drying," scientists writing in the journal Proceedings of the National Academy of Sciences of the United States of America report. "Studies with a model Mycobacterium (Mycobacterium smegmatis) revealed that by removing salts and cryoprotectant (e.g., glycerol) from bacterial suspensions, the significant osmotic pressures that are normally produced on bacterial membranes through droplet drying can be reduced sufficiently to minimize loss of viability on drying by up to 2 orders of magnitude. By placing the bacteria in a matrix of leucine, high-yield, free-flowing, "vial-fillable" powders of bacteria (including M. smegmatis and M. bovis BCG) can be produced. These powders show relatively minor losses of activity after maintenance at 4 degrees C and 25 degrees C up to and beyond 4 months," wrote Y.L. Wong and colleagues, Harvard University. The researchers concluded: "Comparisons with lyophilized material prepared both with the same formulation and with a commercial formulation reveal that the spray-dried BCG has better overall viability on drying." Wong and colleagues published their study in Proceedings of the National Academy of Sciences of the United States of America (Drying a tuberculosis vaccine without freezing. Proceedings of the National Academy of Sciences of the United States of America, 2007;104(8):2591-5). Additional information can be obtained by contacting Y.L. Wong, Harvard University, Division of Engineering and Applied Sciences, Cambridge, MA 02138 USA. The publisher of the journal Proceedings of the National Academy of Sciences of the United States of America can be contacted at: National Acad Sciences, 2101 Constitution Avenue NW, Washington, DC 20418, USA. Keywords: United States, Cambridge, BCG Vaccines, Bacillus Calmette-Guerin Vaccines, Biotechnology, Drug Development, Immunization, Mycobacteria, Mycobacterium Tuberculosis, Therapy, Treatment, Vaccination. This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2007, Biotech Business Week via NewsRx.com.
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