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Phase 2 Placebo-Controlled Trial of Two Vaccines to Prevent Ebola in Liberia.

ABSTRACT: BACKGROUND:The safety and efficacy of vaccines to prevent Ebola virus disease (EVD) were unknown when the incidence of EVD was peaking in Liberia. METHODS:We initiated a randomized, placebo-controlled, phase 3 trial of the chimpanzee adenovirus 3 vaccine (ChAd3-EBO-Z) and the recombinant vesicular stomatitis virus vaccine (rVSV?G-ZEBOV-GP) in Liberia. A phase 2 subtrial was embedded to evaluate safety and immunogenicity. Because the incidence of EVD declined in Liberia, the phase 2 component was expanded and the phase 3 component was eliminated. RESULTS:A total of 1500 adults underwent randomization and were followed for 12 months. The median age of the participants was 30 years; 36.6% of the participants were women. During the week after the administration of vaccine or placebo, adverse events occurred significantly more often with the active vaccines than with placebo; these events included injection-site reactions (in 28.5% of the patients in the ChAd3-EBO-Z group and 30.9% of those in the rVSV?G-ZEBOV-GP group, as compared with 6.8% of those in the placebo group), headache (in 25.1% and 31.9%, vs. 16.9%), muscle pain (in 22.3% and 26.9%, vs. 13.3%), feverishness (in 23.9% and 30.5%, vs. 9.0%), and fatigue (in 14.0% and 15.4%, vs. 8.8%) (P<0.001 for all comparisons); these differences were not seen at 1 month. Serious adverse events within 12 months after injection were seen in 40 participants (8.0%) in the ChAd3-EBO-Z group, in 47 (9.4%) in the rVSV?G-ZEBOV-GP group, and in 59 (11.8%) in the placebo group. By 1 month, an antibody response developed in 70.8% of the participants in the ChAd3-EBO-Z group and in 83.7% of those in the rVSV?G-ZEBOV-GP group, as compared with 2.8% of those in the placebo group (P<0.001 for both comparisons). At 12 months, antibody responses in participants in the ChAd3-EBO-Z group (63.5%) and in those in the rVSV?G-ZEBOV-GP group (79.5%) remained significantly greater than in those in the placebo group (6.8%, P<0.001 for both comparisons). CONCLUSIONS:A randomized, placebo-controlled phase 2 trial of two vaccines that was rapidly initiated and completed in Liberia showed the capability of conducting rigorous research during an outbreak. By 1 month after vaccination, the vaccines had elicited immune responses that were largely maintained through 12 months. (Funded by the National Institutes of Allergy and Infectious Diseases and the Liberian Ministry of Health; PREVAIL I ClinicalTrials.gov number, NCT02344407 .).

SUBMITTER: Kennedy SB

PROVIDER: S-EPMC5705229 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

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Phase 2 Placebo-Controlled Trial of Two Vaccines to Prevent Ebola in Liberia.

Kennedy Stephen B SB Bolay Fatorma F Kieh Mark M Grandits Greg G Badio Moses M Ballou Ripley R Eckes Risa R Feinberg Mark M Follmann Dean D Grund Birgit B Gupta Swati S Hensley Lisa L Higgs Elizabeth E Janosko Krisztina K Johnson Melvin M Kateh Francis F Logue James J Marchand Jonathan J Monath Thomas T Nason Martha M Nyenswah Tolbert T Roman François F Stavale Eric E Wolfson Julian J Neaton James D JD Lane H Clifford HC

The New England journal of medicine 20171001 15

<h4>Background</h4>The safety and efficacy of vaccines to prevent Ebola virus disease (EVD) were unknown when the incidence of EVD was peaking in Liberia.<h4>Methods</h4>We initiated a randomized, placebo-controlled, phase 3 trial of the chimpanzee adenovirus 3 vaccine (ChAd3-EBO-Z) and the recombinant vesicular stomatitis virus vaccine (rVSV∆G-ZEBOV-GP) in Liberia. A phase 2 subtrial was embedded to evaluate safety and immunogenicity. Because the incidence of EVD declined in Liberia, the phase ...[more]

PMID: 29020589

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Project description:OBJECTIVES:Observational studies suggest an association between vitamin D deficiency and adverse outcomes of critical illness and identify it as a potential risk factor for the development of lung injury. To determine whether preoperative administration of oral high-dose cholecalciferol ameliorates early acute lung injury postoperatively in adults undergoing elective esophagectomy. DESIGN:A double-blind, randomized, placebo-controlled trial. SETTING:Three large U.K. university hospitals. PATIENTS:Seventy-nine adult patients undergoing elective esophagectomy were randomized. INTERVENTIONS:A single oral preoperative (3-14 d) dose of 7.5?mg (300,000 IU; 15?mL) cholecalciferol or matched placebo. MEASUREMENTS AND MAIN RESULTS:Primary outcome was change in extravascular lung water index at the end of esophagectomy. Secondary outcomes included PaO2:FIO2 ratio, development of lung injury, ventilator and organ-failure free days, 28 and 90 day survival, safety of cholecalciferol supplementation, plasma vitamin D status (25(OH)D, 1,25(OH)2D, and vitamin D-binding protein), pulmonary vascular permeability index, and extravascular lung water index day 1 postoperatively. An exploratory study measured biomarkers of alveolar-capillary inflammation and injury. Forty patients were randomized to cholecalciferol and 39 to placebo. There was no significant change in extravascular lung water index at the end of the operation between treatment groups (placebo median 1.0 [interquartile range, 0.4-1.8] vs cholecalciferol median 0.4?mL/kg [interquartile range, 0.4-1.2?mL/kg]; p = 0.059). Median pulmonary vascular permeability index values were significantly lower in the cholecalciferol treatment group (placebo 0.4 [interquartile range, 0-0.7] vs cholecalciferol 0.1 [interquartile range, -0.15 to -0.35]; p = 0.027). Cholecalciferol treatment effectively increased 25(OH)D concentrations, but surgery resulted in a decrease in 25(OH)D concentrations at day 3 in both arms. There was no difference in clinical outcomes. CONCLUSIONS:High-dose preoperative treatment with oral cholecalciferol was effective at increasing 25(OH)D concentrations and reduced changes in postoperative pulmonary vascular permeability index, but not extravascular lung water index.

Project description:In the Ebola Virus Disease (EVD) outbreak in Liberia, two major emergency disease-control measures were cremation of bodies and enforcement of quarantine for asymptomatic individuals suspected of being in contact with a positive case. Enforced by State-related actors, these were promoted as the only method to curtail transmissions as soon as possible. However, as with other harsh measures witnessed by Liberian citizens, in many cases those measures elicited uncontrolled negative reactions within the communities (stigma; fear) that produced, in some cases, the opposite effect of that intended.The research has been conducted in two phases, for a total of 8 weeks. Ethnography of local practices was carried out in 7 neighbourhoods in Monrovia and 5 villages in Grand Cape Mount County in Liberia. 45 Focus Group Discussions (432 participants) and 30 semi-structured interviews sustained the observing participation. Randomly selected people from different social layers were targeted. The principal investigator worked with the help of two local assistants. Perceptions and practices were both analysed.Participants stressed how cremation perpetuated the social breakdown that started with the isolation for the sickness. Socio-economical divides were created by inequitable management of the dead: those who could bribe the burial teams obtained a burial in a private cemetery or the use of Funeral Homes. Conversely, those in economic disadvantage were forced to send their dead for cremation. State-enforced quarantine, with a mandatory prohibition of movement, raised condemnation, strengthened stigmatization and created serious socio-economic distress. Food was distributed intermittently and some houses shared latrines with non-quarantined neighbours. Escapes were also recorded. Study participants narrated how they adopted local measures of containment, through local task forces and socially-rooted control of outsiders. They also stressed how information that was not spread built up rumours and suspicion.Populations experiencing an epidemic feel a high degree of social insecurity, in addition to the health hazards. Vertical and coercive measures increase mistrust and fear, producing a counter-productive effect in the containment of the epidemic. On the other hand, local communities show a will to be engaged and a high degree of flexibility in participating to the epidemic response. Efforts in the direction of awareness and community involvement could prove to be better strategy to control the epidemic and root the response on social participation.

Project description:In 2014, a major epidemic of human Ebola virus disease emerged in West Africa, where human-to-human transmission has now been sustained for greater than 12 months. In the summer of 2014, there was great uncertainty about the answers to several key policy questions concerning the path to containment. What is the relative importance of nosocomial transmission compared with community-acquired infection? How much must hospital capacity increase to provide care for the anticipated patient burden? To which interventions will Ebola transmission be most responsive? What must be done to achieve containment? In recent years, epidemic models have been used to guide public health interventions. But, model-based policy relies on high quality causal understanding of transmission, including the availability of appropriate dynamic transmission models and reliable reporting about the sequence of case incidence for model fitting, which were lacking for this epidemic. To investigate the range of potential transmission scenarios, we developed a multi-type branching process model that incorporates key heterogeneities and time-varying parameters to reflect changing human behavior and deliberate interventions in Liberia. Ensembles of this model were evaluated at a set of parameters that were both epidemiologically plausible and capable of reproducing the observed trajectory. Results of this model suggested that epidemic outcome would depend on both hospital capacity and individual behavior. Simulations suggested that if hospital capacity was not increased, then transmission might outpace the rate of isolation and the ability to provide care for the ill, infectious, and dying. Similarly, the model suggested that containment would require individuals to adopt behaviors that increase the rates of case identification and isolation and secure burial of the deceased. As of mid-October, it was unclear that this epidemic would be contained even by 99% hospitalization at the planned hospital capacity. A new version of the model, updated to reflect information collected during October and November 2014, predicts a significantly more constrained set of possible futures. This model suggests that epidemic outcome still depends very heavily on individual behavior. Particularly, if future patient hospitalization rates return to background levels (estimated to be around 70%), then transmission is predicted to remain just below the critical point around Reff = 1. At the higher hospitalization rate of 85%, this model predicts near complete elimination in March to June, 2015.

Project description:BackgroundMultiple health problems have been reported in survivors of Ebola virus disease (EVD). Attribution of these problems to the disease without a control group for analysis is difficult.MethodsWe enrolled a cohort of EVD survivors and their close contacts and prospectively collected data on symptoms, physical examination findings, and laboratory results. A subset of participants underwent ophthalmologic examinations. Persistence of Ebola virus (EBOV) RNA in semen samples from survivors was determined.ResultsA total of 966 EBOV antibody-positive survivors and 2350 antibody-negative close contacts (controls) were enrolled, and 90% of these participants were followed for 12 months. At enrollment (median time to baseline visit, 358 days after symptom onset), six symptoms were reported significantly more often among survivors than among controls: urinary frequency (14.7% vs. 3.4%), headache (47.6% vs. 35.6%), fatigue (18.4% vs. 6.3%), muscle pain (23.1% vs. 10.1%), memory loss (29.2% vs. 4.8%), and joint pain (47.5% vs. 17.5%). On examination, more survivors than controls had abnormal abdominal, chest, neurologic, and musculoskeletal findings and uveitis. Other than uveitis (prevalence at enrollment, 26.4% vs. 12.1%; at year 1, 33.3% vs. 15.4%), the prevalence of these conditions declined during follow-up in both groups. The incidence of most symptoms, neurologic findings, and uveitis was greater among survivors than among controls. EBOV RNA was detected in semen samples from 30% of the survivors tested, with a maximum time from illness to detection of 40 months.ConclusionsA relatively high burden of symptoms was seen in all participants, but certain symptoms and examination findings were more common among survivors. With the exception of uveitis, these conditions declined in prevalence during follow-up in both groups. Viral RNA in semen persisted for a maximum of 40 months. (Funded by the National Institute of Allergy and Infectious Diseases and the National Eye Institute; PREVAIL III ClinicalTrials.gov number, NCT02431923.).

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Phase 2 Placebo-Controlled Trial of Two Vaccines to Prevent Ebola in Liberia.

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Phase 2 Placebo-Controlled Trial of Two Vaccines to Prevent Ebola in Liberia.

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