Sifontes S, Infante J F, Pérez P, Caro E, Sierra G, Campa C
Centro de Bioactivos Químicos, Universidad Central, Las Villas, Habana, Cuba.
Arch Med Res. 1997 Spring;28(1):41-5.
VA-MENGOC-BC is a vaccine against B and C serogroups of Neisseria meningitidis. Its effectiveness at population level has been shown after the application of the vaccine in Cuba, Brazil, Argentina and Colombia. In vitro assays are not always able to reproduce the microorganism-host relationships and this makes it necessary to compile and standardize results obtained in animal models to extrapolate them with a greater degree of safety for humans. We evaluated the effectiveness of VA-MENGOC-BC against Neisseria meningitidis group B isolates from clinically ill patients in Latin America (Argentina, B not typeable: P1; Chile, not typed; Colombia, B4:P1.15 and Cuba B4:P1.15) using Balb/cJ mice treated with iron to make them susceptible to Neisseria meningitidis. The lethal median dose of each strain and of two others that were not included in challenge assays (Brazil: P1.15 and Argentina, B2b:P1.10) were determined. Results were 2.68 x 10(6), 3.16 x 10(7), 1.98 x 10(8), 1.28 x 10(9), 6.42 x 10(6) and 3.88 x 10(7) colony forming units (CFU), respectively. Non-immunized animals and mice treated with one and two doses of VA-MENGOC-BC were challenged with 10(3)-(10) CFU. Protection ranged from 30 to 100% with one dose and was equal to or higher than 70% with the two-dose immunization schedule. A significant protection could not be observed against the Colombian isolate from the lethality point of view, but the mean time of survival lengthened in immunized animals in relation to the controls. The applied inoculum of this strain was much higher (505 x LD50) than the remaining ones. The protection conferred was evident; nevertheless, more data are needed to determine how relevant the results are to humans.
VA-MENGOC-BC是一种针对脑膜炎奈瑟菌B和C血清群的疫苗。在古巴、巴西、阿根廷和哥伦比亚应用该疫苗后，已显示出其在人群层面的有效性。体外试验并不总能重现微生物与宿主的关系，因此有必要汇总和标准化在动物模型中获得的结果，以便更安全地外推至人类。我们使用经铁处理使其易感染脑膜炎奈瑟菌的Balb/cJ小鼠，评估了VA-MENGOC-BC对拉丁美洲临床患病患者中分离出的B群脑膜炎奈瑟菌（阿根廷，B不可分型：P1；智利，未分型；哥伦比亚，B4:P1.15和古巴B4:P1.15）的有效性。确定了每种菌株以及另外两种未用于攻毒试验的菌株（巴西：P1.15和阿根廷，B2b:P1.10）的半数致死剂量。结果分别为2.68×10⁶、3.16×10⁷、1.98×10⁸、1.28×10⁹、6.42×10⁶和3.88×10⁷菌落形成单位（CFU）。用10³ - 10⁵CFU对未免疫动物以及用一剂和两剂VA-MENGOC-BC处理的小鼠进行攻毒。一剂疫苗的保护率为30%至100%，两剂免疫方案的保护率等于或高于70%。从致死率角度来看，未观察到对哥伦比亚分离株有显著保护作用，但与对照组相比，免疫动物的平均存活时间延长。该菌株的接种量（505×LD50）比其他菌株高得多。所赋予的保护作用是明显的；然而，还需要更多数据来确定这些结果与人类的相关性。
