Incomplete Protection against Dengue Virus Type 2 Re-infection in Peru
Incomplete Protection against Dengue Virus Type 2 Re-infection in Peru
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DOI：
10.1371/journal.pntd.0004398
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发表时间：
2016-02-01
影响因子：
3.8
通讯作者：
Stoddard, Steven T.
中科院分区：
文献类型：
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作者：
Forshey, Brett M.;Reiner, Robert C.;Stoddard, Steven T.
近一半的世界人口面临登革热的风险，但目前还没有获得许可的疫苗或抗病毒药物。登革热是由四种登革热病毒血清型（DENV-1至DENV-4）中的任何一种引起的，并且被DENV血清型感染被认为提供终身保护以防止被该血清型再次感染。我们调查了这一基本假设的有效性，在一个大的登革热流行引起的DENV-2在伊基托斯，秘鲁，在2010-2011年，15年后的第一次爆发DENV-2在region.Methodology/Principal FindingsWe估计的年龄依赖性流行的DENV抗体从1993年和2010年之间进行的纵向队列研究。在2010-2011年流行期间，通过积极的社区和诊所发热监测研究确定了活动性登革热病例，并通过接触者追踪研究确定了急性隐性登革病毒感染。根据DENV-2中和抗体的年龄特异性患病率，DENV-2病例的年龄分布明显高于预期。Homestrant保护率估计为35.1%（95%置信区间：0%-65.2%）。在个体水平上，预先存在的DENV-2抗体与症状频率的不完全减少有关。在登革热病例中，43%（26/66）在感染前数年内表现出DENV-2中和抗体滴度升高，而76%（13/17）的隐性感染（年龄调整的比值比：4.2; 95%置信区间：1.1-17.7）.结论/显著性我们的数据表明，在某些情况下，对同源DENV再感染的保护可能是不完全的，这为最近试验中针对DENV-2的有限疫苗效力提供了背景。进一步的研究是必要的，以证实这一现象，并评估不完全的同源保护在登革病毒传播动力学的潜在作用。
BackgroundNearly half of the world's population is at risk for dengue, yet no licensed vaccine or antiviral drug is currently available. Dengue is caused by any of four dengue virus serotypes (DENV-1 through DENV-4), and infection by a DENV serotype is assumed to provide lifelong protection against re-infection by that serotype. We investigated the validity of this fundamental assumption during a large dengue epidemic caused by DENV-2 in Iquitos, Peru, in 2010-2011, 15 years after the first outbreak of DENV-2 in the region.Methodology/Principal FindingsWe estimated the age-dependent prevalence of serotype-specific DENV antibodies from longitudinal cohort studies conducted between 1993 and 2010. During the 2010-2011 epidemic, active dengue cases were identified through active community- and clinic-based febrile surveillance studies, and acute inapparent DENV infections were identified through contact tracing studies. Based on the age-specific prevalence of DENV-2 neutralizing antibodies, the age distribution of DENV-2 cases was markedly older than expected. Homologous protection was estimated at 35.1% (95% confidence interval: 0%-65.2%). At the individual level, pre-existing DENV-2 antibodies were associated with an incomplete reduction in the frequency of symptoms. Among dengue cases, 43% (26/66) exhibited elevated DENV-2 neutralizing antibody titers for years prior to infection, compared with 76% (13/17) of inapparent infections (age-adjusted odds ratio: 4.2; 95% confidence interval: 1.1-17.7).Conclusions/SignificanceOur data indicate that protection from homologous DENV re-infection may be incomplete in some circumstances, which provides context for the limited vaccine efficacy against DENV-2 in recent trials. Further studies are warranted to confirm this phenomenon and to evaluate the potential role of incomplete homologous protection in DENV transmission dynamics.