Incomplete Protection against Dengue Virus Type 2 Re-infection in Peru.
| Autor: | Brett M Forshey, Robert C Reiner, Sandra Olkowski, Amy C Morrison, Angelica Espinoza, Kanya C Long, Stalin Vilcarromero, Wilma Casanova, Helen J Wearing, Eric S Halsey, Tadeusz J Kochel, Thomas W Scott, Steven T Stoddard |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | PLoS Neglected Tropical Diseases, Vol 10, Iss 2, p e0004398 (2016) |
| Druh dokumentu: | article |
| ISSN: | 1935-2727 1935-2735 |
| DOI: | 10.1371/journal.pntd.0004398 |
| Popis: | BACKGROUND:Nearly half of the world's population is at risk for dengue, yet no licensed vaccine or anti-viral 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 life-long 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 FINDINGS:We 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/SIGNIFICANCE:Our 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. |
| Databáze: | Directory of Open Access Journals |
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