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DC Field | Value | Language |
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dc.contributor.author | Guinovart, Caterina | - |
dc.contributor.author | Aponte, John J. | - |
dc.contributor.author | Sacarlal, Jahit | - |
dc.contributor.author | Aide, Pedro Carlos Paulino | - |
dc.contributor.author | Leach, Amanda | - |
dc.contributor.author | Bassat Orellana, Quique | - |
dc.contributor.author | Macete, Eusebio Víctor | - |
dc.contributor.author | Dobaño, Carlota, 1969- | - |
dc.contributor.author | Lievens, Marc | - |
dc.contributor.author | Loucq, Christian | - |
dc.contributor.author | Ballou, W. Ripley | - |
dc.contributor.author | Cohen, Joe | - |
dc.contributor.author | Alonso, Pedro | - |
dc.date.accessioned | 2016-03-01T11:05:25Z | - |
dc.date.available | 2016-03-01T11:05:25Z | - |
dc.date.issued | 2009-04-14 | - |
dc.identifier.issn | 1932-6203 | - |
dc.identifier.uri | http://hdl.handle.net/2445/96008 | - |
dc.description.abstract | Background: The pre-erythrocytic malaria vaccine RTS,S/AS02A has shown to confer protection against clinical malaria for at least 21 months in a trial in Mozambican children. Efficacy varied between different endpoints, such as parasitaemia or clinical malaria; however the underlying mechanisms that determine efficacy and its duration remain unknown. We performed a new, exploratory analysis to explore differences in the duration of protection among participants to better understand the protection afforded by RTS,S. Methodology/Principal Findings: The study was a Phase IIb double-blind, randomized controlled trial in 2022 children aged 1 to 4 years. The trial was designed with two cohorts to estimate vaccine efficacy against two different endpoints: clinical malaria (cohort 1) and infection (cohort 2). Participants were randomly allocated to receive three doses of RTS,S/AS02A or control vaccines. We did a retrospective, unplanned sub-analysis of cohort 2 data using information collected for safety through the health facility-based passive case detection system. Vaccine efficacy against clinical malaria was estimated over the first six-month surveillance period (double-blind phase) and over the following 12 months (single-blind phase), and analysis was per-protocol. Adjusted vaccine efficacy against first clinical malaria episodes in cohort 2 was of 35.4% (95% CI 4.5-56.3; p = 0.029) over the double-blind phase and of 9.0% (230.6-36.6; p = 0.609) during the single-blind phase. Conclusions/Significance: Contrary to observations in cohort 1, where efficacy against clinical malaria did not wane over time, in cohort 2 the efficacy decreases with time. We hypothesize that this reduced duration of protection is a result of the early diagnosis and treatment of infections in cohort 2 participants, preventing sufficient exposure to asexual-stage antigens. On the other hand, the long-term protection against clinical disease observed in cohort 1 may be a consequence of a prolonged exposure to low-dose blood-stage asexual parasitaemia. | - |
dc.format.extent | 8 p. | - |
dc.format.mimetype | application/pdf | - |
dc.language.iso | eng | - |
dc.publisher | Public Library of Science (PLoS) | - |
dc.relation.isformatof | Reproducció del document publicat a: http://dx.doi.org/10.1371/journal.pone.0005165 | - |
dc.relation.ispartof | PLoS One, 2009, vol. 4, num. 4, p. e5165 | - |
dc.relation.uri | http://dx.doi.org/10.1371/journal.pone.0005165 | - |
dc.rights | cc-by (c) Guinovart, C. et al., 2009 | - |
dc.rights.uri | http://creativecommons.org/licenses/by/3.0/es | - |
dc.source | Articles publicats en revistes (Medicina) | - |
dc.subject.classification | Vacuna de la malària | - |
dc.subject.classification | Infants | - |
dc.subject.classification | Moçambic | - |
dc.subject.classification | Assaigs clínics | - |
dc.subject.other | Malaria vaccine | - |
dc.subject.other | Children | - |
dc.subject.other | Mozambique | - |
dc.subject.other | Clinical trials | - |
dc.title | Insights into long-lasting protection induced by RTS,S/AS02A malaria vaccine: further results from a phase IIb trial in Mozambican children | - |
dc.type | info:eu-repo/semantics/article | - |
dc.type | info:eu-repo/semantics/publishedVersion | - |
dc.identifier.idgrec | 573186 | - |
dc.date.updated | 2016-03-01T11:05:30Z | - |
dc.rights.accessRights | info:eu-repo/semantics/openAccess | - |
dc.identifier.pmid | 19365567 | - |
Appears in Collections: | Articles publicats en revistes (Medicina) |
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573186.pdf | 308.46 kB | Adobe PDF | View/Open |
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