Randomized Trial of Vaccines for Zaire Ebola Virus Disease.

BACKGROUND: Questions remain concerning the rapidity of immune responses and the durability and safety of vaccines used to prevent Zaire Ebola virus disease. METHODS: We conducted two randomized, placebo-controlled trials - one involving adults and one involving children - to evaluate the safety and immune responses of three vaccine regimens against Zaire Ebola virus disease: Ad26.ZEBOV followed by MVA-BN-Filo 56 days later (the Ad26-MVA group), rVSVΔG-ZEBOV-GP followed by placebo 56 days later (the rVSV group), and rVSVΔG-ZEBOV-GP followed by rVSVΔG-ZEBOV-GP 56 days later (the rVSV-booster group). The primary end point was antibody response at 12 months, defined as having both a 12-month antibody concentration of at least 200 enzyme-linked immunosorbent assay units (EU) per milliliter and an increase from baseline in the antibody concentration by at least a factor of 4. RESULTS: A total of 1400 adults and 1401 children underwent randomization. Among both adults and children, the incidence of injection-site reactions and symptoms (e.g., feverishness and headache) was higher in the week after receipt of the primary and second or booster vaccinations than after receipt of placebo but not at later time points. These events were largely low-grade. At month 12, a total of 41% of adults (titer, 401 EU per milliliter) and 78% of children (titer, 828 EU per milliliter) had a response in the Ad26-MVA group; 76% (titer, 992 EU per milliliter) and 87% (titer, 1415 EU per milliliter), respectively, had a response in the rVSV group; 81% (titer, 1037 EU per milliliter) and 93% (titer, 1745 EU per milliliter), respectively, had a response in the rVSV-booster group; and 3% (titer, 93 EU per milliliter) and 4% (titer, 67 EU per milliliter), respectively, had a response in the placebo group (P<0.001 for all comparisons of vaccine with placebo). In both adults and children, antibody responses with vaccine differed from those with placebo beginning on day 14. CONCLUSIONS: No safety concerns were identified in this trial. With all three vaccine regimens, immune responses were seen from day 14 through month 12. (Funded by the National Institutes of Health and others; PREVAC ClinicalTrials.gov number, NCT02876328; EudraCT numbers, 2017-001798-18 and 2017-001798-18/3rd; and Pan African Clinical Trials Registry number, PACTR201712002760250.).

Preparedness and vulnerability of African countries against importations of COVID-19: a modelling study.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) epidemic has spread from China to 25 countries. Local cycles of transmission have already occurred in 12 countries after case importation. In Africa, Egypt has so far confirmed one case. The management and control of COVID-19 importations heavily rely on a country's health capacity. Here we evaluate the preparedness and vulnerability of African countries against their risk of importation of COVID-19. METHODS: We used data on the volume of air travel departing from airports in the infected provinces in China and directed to Africa to estimate the risk of importation per country. We determined the country's capacity to detect and respond to cases with two indicators: preparedness, using the WHO International Health Regulations Monitoring and Evaluation Framework; and vulnerability, using the Infectious Disease Vulnerability Index. Countries were clustered according to the Chinese regions contributing most to their risk. FINDINGS: Countries with the highest importation risk (ie, Egypt, Algeria, and South Africa) have moderate to high capacity to respond to outbreaks. Countries at moderate risk (ie, Nigeria, Ethiopia, Sudan, Angola, Tanzania, Ghana, and Kenya) have variable capacity and high vulnerability. We identified three clusters of countries that share the same exposure to the risk originating from the provinces of Guangdong, Fujian, and the city of Beijing, respectively. INTERPRETATION: Many countries in Africa are stepping up their preparedness to detect and cope with COVID-19 importations. Resources, intensified surveillance, and capacity building should be urgently prioritised in countries with moderate risk that might be ill-prepared to detect imported cases and to limit onward transmission. FUNDING: EU Framework Programme for Research and Innovation Horizon 2020, Agence Nationale de la Recherche.

The emm-cluster typing system for Group A Streptococcus identifies epidemiologic similarities across the Pacific region.

BACKGROUND: Group A Streptococcus (GAS)-related disease is responsible for high mortality and morbidity in the Pacific region. The high diversity of circulating strains in this region has hindered vaccine development due to apparently low vaccine coverage of type-specific vaccines. METHOD: Prospective passive surveillance of all GAS isolates in New Caledonia was undertaken in 2012 using emm typing and emm-cluster typing. Molecular data were compared with the results from a prior study undertaken in the same country and with data from 2 other Pacific countries, Fiji and Australia. RESULTS: A high incidence of invasive infection was demonstrated at 43 cases per 100 000 inhabitants (95% confidence interval, 35-52 cases per 100 000 inhabitants). Three hundred eighteen GAS isolates belonging to 47 different emm types were collected. In Noumea, only 30% of the isolates recovered in 2012 belonged to an emm type that was present in the same city in 2006, whereas 69% of the isolates collected in 2012 belonged to an emm cluster present in 2006. When comparing New Caledonian, Australian, and Fijian data, very few common emm types were found, but 79%-86% of the isolates from each country belonged to an emm cluster present in all 3 countries. A vaccine that could protect against the 10 most frequent emm clusters in the Pacific region would potentially provide coverage ranging from 83% to 92%. CONCLUSIONS: This study confirms the high disease burden of GAS infection in New Caledonia and supports the added value of the emm-cluster typing system to analyze GAS epidemiology and to help inform global GAS vaccine formulation.

Determinants of poor adherence to secondary antibiotic prophylaxis for rheumatic fever recurrence on Lifou, New Caledonia: a retrospective cohort study.

BACKGROUND: Incidence of acute rheumatic fever (ARF) and prevalence of rheumatic heart disease (RHD) in the Pacific region, including New Caledonia, are amongst the highest in the world. The main priority of long-term management of ARF or RHD is to ensure secondary prophylaxis is adhered to. The objectives of this study were to evaluate rates of adherence in people receiving antibiotic prophylaxis by intramuscular injections of penicillin in Lifou and to determine the factors associated with a poor adherence in this population. METHODS: We conducted a retrospective cohort study and we included 70 patients receiving injections of antibiotic prophylaxis to prevent ARF recurrence on the island of Lifou. Patients were classified as "good-adherent" when the rate of adherence was ≥80% of the expected injections and as "poor-adherent" when it was <80%. Statistical analysis to identify factors associated with adherence was performed using a multivariate logistic regression model. RESULTS: Our study showed that 46% of patients from Lifou receiving antibiotic prophylaxis for ARF or RHD had a rate of adherence <80% and were therefore at high risk of recurrence of ARF. Three independent factors were protective against poor adherence: a household with more than five people (odds ratio, 0.25; 95% confidence interval [CI], 0.08 to 0.75), a previous medical history of symptomatic ARF (odds ratio, 0.20; 95% CI, 0.04 to 0.98) and an adequate healthcare coverage (odds ratio, 0.21; 95% CI 0.06 to 0.72). CONCLUSIONS: To improve adherence to secondary prophylaxis in Lifou, we therefore propose the following recommendations arising from the results of this study: i) identifying patients receiving antibiotic prophylaxis without medical history of ARF to strengthen their therapeutic education and ii) improving the medical coverage in patients with ARF or RHD. We also recommend that the nurse designated for the ARF prevention program in Lifou coordinate an active recall system based on an updated local register. But the key point to improve adherence among Melanesian patients is probably to give appropriate information regarding the disease and the treatment, taking into account the Melanesian perceptions of the disease.

High prevalence of rheumatic heart disease in schoolchildren detected by echocardiography screening in New Caledonia.

AIM: Despite the well-documented burden of rheumatic heart disease (RHD) in several Pacific countries, the disease is poorly understood in New Caledonia. The aim of this study was to assess the prevalence of RHD detected by echocardiographic screening in school children. METHODS: An annual RHD screening programme is conducted by the Health and Social Agency of New Caledonia for school-aged children in their fourth year of primary school. For the purpose of this study, we used data collected during this echocardiographic screening between 2008 and 2010. RESULTS: Of 12,728 children screened, 50.2% were male and the mean age was 9.6 ± 0.6 years. Between 2008 and 2010, 114 children had RHD, corresponding to a prevalence of 8.9 cases per 1000 (95% confidence interval (CI) (7.3-10.6)). Prevalence of RHD was higher on the main island outside Greater Noumea (13.7 per 1000; 95% CI (9.8-17.5)) and in the outlying island groups (14.6 per 1000; 95% CI (8.4-20.9)) than in Greater Noumea (5.8 per 1000; 95% CI (4.1-7.5)). RHD was more prevalent in Melanesian children (13.5 per 1000; 95% CI (10.9-16.1)) than in European (1.8 per 1000; 95% CI (0.4-3.1)). CONCLUSION: This study documented a high prevalence of RHD in New Caledonia, particularly in districts located outside Noumea and in children of Melanesian heritage. These results uncover a hitherto unknown burden of disease in New Caledonia and underline the importance of delivering secondary prophylaxis to reduce the prevalence of RHD.

Immune response of a two-dose heterologous Ebola vaccine regimen: summary of three African clinical trials using a single validated Filovirus Animal Nonclinical Group enzyme-linked immunosorbent assay in a single accredited laboratory.

BACKGROUND: This analysis evaluated the immune response to the two-dose, heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola virus vaccine regimen, administered 56-days apart, from multiple African sites based on results from one analytic laboratory. METHODS: Immunogenicity across three trials (EBL2002, EBL2004/PREVAC, EBL3001) conducted in East and West Africa is summarised. Vaccine-induced Ebola glycoprotein-binding antibody concentrations were analysed by Q2 Solutions laboratory at baseline, 21 days (EBL2002 and EBL3001) or 28 days (EBL2004) post-dose 2 (regimen completion), and 12 months post-dose 1 using the validated Filovirus Animal Nonclinical Group Ebola glycoprotein enzyme-linked immunosorbent assay (ELISA). Responders were defined as those with a >2.5-fold increase from baseline or the lower limit of quantification (LLOQ) if 

Safety and immunogenicity of the two-dose heterologous Ad26.ZEBOV and MVA-BN-Filo Ebola vaccine regimen in infants: a phase 2, randomised, double-blind, active-controlled trial in Guinea and Sierra Leone.

BACKGROUND: This study assessed the safety and immunogenicity of the Ad26.ZEBOV and MVA-BN-Filo Ebola virus (EBOV) vaccine regimen in infants aged 4-11 months in Guinea and Sierra Leone. METHODS: In this phase 2, randomised, double-blind, active-controlled trial, we randomly assigned healthy infants (1:1 in a sentinel cohort, 5:2 for the remaining infants via an interactive web response system) to receive Ad26.ZEBOV followed by MVA-BN-Filo (Ebola vaccine group) or two doses of meningococcal quadrivalent conjugate vaccine (control group) administered 56 days apart. Infants were recruited at two sites in west Africa: Conakry, Guinea, and Kambia, Sierra Leone. All infants received the meningococcal vaccine 8 months after being randomly assigned. The primary objective was safety. The secondary objective was immunogenicity, measured as EBOV glycoprotein-binding antibody concentration 21 days post-dose 2, using the Filovirus Animal Non-Clinical Group ELISA. This study is registered with ClinicalTrials.gov (NCT03929757) and the Pan African Clinical Trials Registry (PACTR201905827924069). FINDINGS: From Aug 20 to Nov 29, 2019, 142 infants were screened and 108 were randomly assigned (Ebola vaccine n=75; control n=33). The most common solicited local adverse event was injection-site pain (Ebola vaccine 15 [20%] of 75; control four [12%] of 33). The most common solicited systemic adverse events with the Ebola vaccine were irritability (26 [35%] of 75), decreased appetite (18 [24%] of 75), pyrexia (16 [21%] of 75), and decreased activity (15 [20%] of 75). In the control group, ten (30%) of 33 had irritability, seven (21%) of 33 had decreased appetite, three (9%) of 33 had pyrexia, and five (15%) of 33 had decreased activity. The frequency of unsolicited adverse events was 83% (62 of 75 infants) in the Ebola vaccine group and 85% (28 of 33 infants) in the control group. No serious adverse events were vaccine-related. In the Ebola vaccine group, EBOV glycoprotein-binding antibody geometric mean concentrations (GMCs) at 21 days post-dose 2 were 27 700 ELISA units (EU)/mL (95% CI 20 477-37 470) in infants aged 4-8 months and 20 481 EU/mL (15 325-27 372) in infants aged 9-11 months. The responder rate was 100% (74 of 74 responded). In the control group, GMCs for both age groups were less than the lower limit of quantification and the responder rate was 3% (one of 33 responded). INTERPRETATION: Ad26.ZEBOV and MVA-BN-Filo was well tolerated and induced strong humoral responses in infants younger than 1 year. There were no safety concerns related to vaccination. FUNDING: Janssen Vaccines & Prevention and Innovative Medicines Initiative 2 Joint Undertaking. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Lower respiratory infections among hospitalized children in New Caledonia: a pilot study for the Pneumonia Etiology Research for Child Health project.

We conducted a prospective pilot study over a 1-year period in New Caledonia in preparation for the Pneumonia Research for Child Health (PERCH) project. The pathogens associated with hospitalized lower respiratory infections in children were identified through the use of culture of induced sputum and blood, urinary antigen detection, polymerase chain reaction (PCR) on respiratory specimens, and serology on paired sera. Respiratory viruses were detected on respiratory specimens by immunofluorescence and PCR, and by serology on paired sera. Pathogens were detected in 87.9% of the 108 hospitalized cases. Viruses represented 81.6% of the 152 pathogens detected. Respiratory syncytial virus and rhinovirus were the most frequent, accounting for 32.2% and 24.3% of the pathogens identified, respectively. Only 26.3% of 99 induced sputum specimens collected were determined to be of good quality, which may be a consequence of the collection method used.

Health crisis: What opportunities for clinical drug research?

The COVID-19 pandemic led to the deployment of an unprecedented academic and industrial research effort, the sometimes redundant nature of which is regrettable, as is the lack of both national and international management. However, it must be noted that during this crisis, regulatory procedures were adapted and certain obstacles in the organisation of clinical research were partly removed to contribute to the deployment of trials as close as possible to patients and to facilitate monitoring and control procedures. The digitisation of certain processes and the decentralisation of certain activities were implemented under the cover of a mobilisation of the authorities and all institutional, academic and industrial players. While in the UK, the optimisation of resources through a single platform trial has made it possible to demonstrate or invalidate the efficacy of many treatments, in France the health crisis has highlighted the fragility of the organisation of clinical research, in particular a lack of coordination and funding, difficulties in implementing studies and a certain reluctance to share data. However, the crisis has also revealed the adaptability of the various stakeholders and has led to the improvement of several processes useful for the deployment of therapeutic innovation. Let us hope that the lessons learned during this crisis will allow for greater efficiency in the event of a new pandemic and, above all, that the progress made will continue to apply to all future clinical research activities.

Partnership for Research on Ebola VACcination (PREVAC): protocol of a randomized, double-blind, placebo-controlled phase 2 clinical trial evaluating three vaccine strategies against Ebola in healthy volunteers in four West African countries.

INTRODUCTION: The Ebola virus disease (EVD) outbreak in 2014-2016 in West Africa was the largest on record and provided an opportunity for large clinical trials and accelerated efforts to develop an effective and safe preventative vaccine. Multiple questions regarding the safety, immunogenicity, and efficacy of EVD vaccines remain unanswered. To address these gaps in the evidence base, the Partnership for Research on Ebola Vaccines (PREVAC) trial was designed. This paper describes the design, methods, and baseline results of the PREVAC trial and discusses challenges that led to different protocol amendments. METHODS: This is a randomized, double-blind, placebo-controlled phase 2 clinical trial of three vaccine strategies against the Ebola virus in healthy volunteers 1 year of age and above. The three vaccine strategies being studied are the rVSVΔG-ZEBOV-GP vaccine, with and without a booster dose at 56 days, and the Ad26.ZEBOV,MVA-FN-Filo vaccine regimen with Ad26.ZEBOV given as the first dose and the MVA-FN-Filo vaccination given 56 days later. There have been 4 versions of the protocol with those enrolled in Version 4.0 comprising the primary analysis cohort. The primary endpoint is based on the antibody titer against the Ebola virus surface glycoprotein measured 12 months following the final injection. RESULTS: From April 2017 to December 2018, a total of 5002 volunteers were screened and 4789 enrolled. Participants were enrolled at 6 sites in four countries (Guinea, Liberia, Sierra Leone, and Mali). Of the 4789 participants, 2560 (53%) were adults and 2229 (47%) were children. Those < 18 years of age included 549 (12%) aged 1 to 4 years, 750 (16%) 5 to 11 years, and 930 (19%) aged 12-17 years. At baseline, the median (25th, 75th percentile) antibody titer to Ebola virus glycoprotein for 1090 participants was 72 (50, 116) EU/mL. DISCUSSION: The PREVAC trial is evaluating-placebo-controlled-two promising Ebola candidate vaccines in advanced stages of development. The results will address unanswered questions related to short- and long-term safety and immunogenicity for three vaccine strategies in adults and children. TRIAL REGISTRATION: ClinicalTrials.gov NCT02876328 . Registered on 23 August 2016.

Human plague: An old scourge that needs new answers.

Yersinia pestis, the bacterial causative agent of plague, remains an important threat to human health. Plague is a rodent-borne disease that has historically shown an outstanding ability to colonize and persist across different species, habitats, and environments while provoking sporadic cases, outbreaks, and deadly global epidemics among humans. Between September and November 2017, an outbreak of urban pneumonic plague was declared in Madagascar, which refocused the attention of the scientific community on this ancient human scourge. Given recent trends and plague's resilience to control in the wild, its high fatality rate in humans without early treatment, and its capacity to disrupt social and healthcare systems, human plague should be considered as a neglected threat. A workshop was held in Paris in July 2018 to review current knowledge about plague and to identify the scientific research priorities to eradicate plague as a human threat. It was concluded that an urgent commitment is needed to develop and fund a strong research agenda aiming to fill the current knowledge gaps structured around 4 main axes: (i) an improved understanding of the ecological interactions among the reservoir, vector, pathogen, and environment; (ii) human and societal responses; (iii) improved diagnostic tools and case management; and (iv) vaccine development. These axes should be cross-cutting, translational, and focused on delivering context-specific strategies. Results of this research should feed a global control and prevention strategy within a "One Health" approach.