目前的狂犬病疫苗的费用和低效导致需要重复接种,而且妨碍了根除狗的这种致命疾病的努力——特别是在发展中国家。科学家如今朝着只需要接种1份的狂犬病疫苗的目标又走近了一步。
Bernhard Dietzschold及其同事报告说,一种重组DNA技术可以用于制造一种减毒活疫苗,它可以保护接种者不受狂犬病感染,而且可以在感染后从脑中清除狂犬病。在小鼠身上试验的其他版本的狂犬病活疫苗导致了让人无法接受的疾病高风险。然而,这种新疫苗甚至在出生5天的免疫系统未成熟的小鼠身上也不会导致该病。这种称为SPBAANGAS-GAS-GAS的疫苗也能保护成年和免疫缺损的小鼠接触高毒力狂犬病毒株而不被感染。尽管传统的狂犬病暴露后治疗需要多次注射疫苗,注射一次这种重组疫苗就可以清除小鼠大脑中已经出现的狂犬病感染。这组作者说,这种疫苗代表了一种预防、治疗、或许还能根除狂犬病的有希望的候选疫苗。(生物谷Bioon.com)
生物谷推荐原始出处:
PNAS July 6, 2009, doi: 10.1073/pnas.0905640106
Effective preexposure and postexposure prophylaxis of rabies with a highly attenuated recombinant rabies virus
Milosz Fabera, Jianwei Lia, Rhonda B. Keanb, D. Craig Hooperb, Kishore R. Alugupallia and Bernhard Dietzscholda,1
aDepartment of Microbiology and Immunology and
bDepartment of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
Rabies remains an important public health problem with more than 95% of all human rabies cases caused by exposure to rabid dogs in areas where effective, inexpensive vaccines are unavailable. Because of their ability to induce strong innate and adaptive immune responses capable of clearing the infection from the CNS after a single immunization, live-attenuated rabies virus (RV) vaccines could be particularly useful not only for the global eradication of canine rabies but also for late-stage rabies postexposure prophylaxis of humans. To overcome concerns regarding the safety of live-attenuated RV vaccines, we developed the highly attenuated triple RV G variant, SPBAANGAS-GAS-GAS. In contrast to most attenuated recombinant RVs generated thus far, SPBAANGAS-GAS-GAS is completely nonpathogenic after intracranial infection of mice that are either developmentally immunocompromised (e.g., 5-day-old mice) or have inherited deficits in immune function (e.g., antibody production or type I IFN signaling), as well as normal adult animals. In addition, SPBAANGAS-GAS-GAS induces immune mechanisms capable of containing a CNS infection with pathogenic RV, thereby preventing lethal rabies encephalopathy. The lack of pathogenicity together with excellent immunogenicity and the capacity to deliver immune effectors to CNS tissues makes SPBAANGAS-GAS-GAS a promising vaccine candidate for both the preexposure and postexposure prophylaxis of rabies.