Shaping the phylogenetic tree of influenza by cross-immunity
Shaping the phylogenetic tree of influenza by cross-immunity
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DOI：
10.1016/j.tpb.2006.04.004
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发表时间：
2006-09-01
影响因子：
1.4
通讯作者：
Sasaki, Akira
中科院分区：
文献类型：
--
作者：
Andreasen, Viggo;Sasaki, Akira
相关毒株之间的交叉免疫可以解释人类甲型和乙型流感细长系统发育树的选择。使用带有漂移的季节性流感流行模型(Andreasen，2003)。免疫选择对甲型流感年度流行的动态影响。J·数学。比奥尔。46,504-536)，并假设两个突变体依次进入宿主群体，在第一个突变体与其共同祖先引起部分交叉保护的情况下，我们确定了建立第二个突变体的阈值条件。对于固定的交叉保护水平，第二个突变体建立的机会随着p的增加而增加基本繁殖率，一些临时免疫可能是解释流感系统发生树的细长所必需的。在暂时免疫水平适中的情况下，在引入并建立两个突变体后的那个季节，可能会出现一种不对称的情况：如果新突变体的后代在常驻类型的后代之前到达，那么突变系可能会产生大规模的流行病，压制最初的血统。然而，如果原始谱系首先到达，那么两个菌株都可能建立，系统发育树可能会分叉。(C)2006 Elsevier Inc.保留所有权利。
Cross-immunity among related strains can account for the selection producing the slender phylogenetic tree of influenza A and B in humans. Using a model of seasonal influenza epidemics with drift (Andreasen, 2003. Dynamics of annual influenza A epidemics with immuno-selection. J. Math. Biol. 46, 504-536), and assuming that two mutants arrive in the host population sequentially, we determine the threshold condition for the establishment of the second mutant in the presence of partial cross-protection caused by the first mutant and their common ancestors. For fixed levels of cross-protection, the chance that the second mutant establishes increases with p the basic reproduction ratio and some temporary immunity may be necessary to explain the slenderness of flu's phylogenetic tree. In the presence of moderate levels of temporary immunity, an asymmetric situation can arise in the season after the two mutants were introduced and established: if the offspring of the new mutant arrives before the offspring of the resident type, then the mutant-line may produce a massive epidemic suppressing the original lineage. However, if the original lineage arrives first then both strains may establish and the phylogenetic tree may bifurcate. (c) 2006 Elsevier Inc. All rights reserved.