Safety and immunogenicity of BK-SE36/CpG malaria vaccine in healthy Burkinabe adults and children: a phase 1b randomised, controlled, double-blinded, age de-escalation trial.

Background: BK-SE36/CpG is a recombinant blood-stage malaria vaccine candidate based on the N-terminal Plasmodium falciparum serine repeat antigen5 (SE36), adsorbed to aluminium hydroxide gel and reconstituted, prior to administration, with synthetic oligodeoxynucleotides bearing CpG motifs. In healthy Japanese adult males, BK-SE36/CpG was well tolerated. This study assessed its safety and immunogenicity in healthy malaria-exposed African adults and children. Methods: A double-blind, randomised, controlled, age de-escalating clinical trial was conducted in an urban area of Ouagadougou, Burkina Faso. Healthy participants (n=135) aged 21-45 years (Cohort 1), 5-10 years (Cohort 2) and 12-24 months (Cohort 3) were randomised to receive three vaccine doses (Day 0, 28 and 112) of BK-SE36/CpG or rabies vaccine by intramuscular injection. Results: One hundred thirty-four of 135 (99.2%) subjects received all three scheduled vaccine doses. Vaccinations were well tolerated with no related Grade 3 (severe) adverse events (AEs). Pain/limitation of limb movement, headache in adults and fever in younger children (all mild to moderate in intensity) were the most frequently observed local and systemic AEs. Eighty-three of BK-SE36/CpG (91%) recipients and 37 of control subjects (84%) had Grade 1/2 events within 28 days post vaccination. Events considered by the investigator to be vaccine related were experienced by 38% and 14% of subjects in BK-SE36/CpG and control arms, respectively. Throughout the trial, six Grade 3 events (in 4 subjects), not related to vaccination, were recorded in the BK-SE36/CpG arm: 5 events (in 3 subjects) within 28 days of vaccination. All serious adverse events (SAEs) (n=5) were due to severe malaria (52-226 days post vaccination) and not related to vaccination. In all cohorts, BK-SE36/CpG arm had higher antibody titres after Dose 3 than after Dose 2. Younger cohorts had stronger immune responses (12-24-month-old > 5-10 years-old > 21-45 years-old). Sera predominantly reacted to peptides that lie in intrinsically unstructured regions of SE36. In the control arm, there were no marked fold changes in antibody titres and participants' sera reacted poorly to all peptides spanning SE36. Conclusion: BK-SE36/CpG was well-tolerated and immunogenic. These results pave the way for further proof-of-concept studies to demonstrate vaccine efficacy. Clinical trial registration: https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1921, PACTR201701001921166.

High prevalence of malnutrition in systemic sclerosis: Results from a French monocentric cross-sectional study.

OBJECTIVES: Systemic sclerosis (SSc) can cause malnutrition due to frequent gastrointestinal involvement. However, prevalence of malnutrition in SSc is poorly known. The aim of this study was to evaluate the prevalence of malnutrition in SSc and its potential associations with disease features in patients from a tertiary referral center. METHODS: All patients meeting American College of Rheumatology/European Alliance of Associations for Rheumatology criteria for SSc followed between January 1, 1985, and January 1, 2019, at the Department of Internal Medicine, Saint Eloi University Hospital, were included. Malnutrition was assessed using the 2020 French recommendations for SSc and the malnutrition universal screening tool score. Severe malnutrition was defined via the French Haute Autorité de Santé (National Health Authority) 2007 criteria. RESULTS: A total of 120 patients were included, with mean age 64 (± 15) y and a female-to-male sex ratio of 5:1. According to 2020 French recommendations, 71 patients (59.2%) were malnourished and 30 (25%) had at least one criterion of severe malnutrition. With the malnutrition universal screening tool score, 41.7%, 20%, and 38.3%, respectively, had low, medium, and high risk of malnutrition. Multivariate analysis revealed the following results: 1) malnutrition was associated with cardiac involvement (P < 0.01); 2) a high malnutrition universal screening tool score was also associated with specific cardiac involvement (P < 0.01); and 3) severe malnutrition was strongly correlated with interincisal distance <35 mm (P = 0.02). CONCLUSIONS: Malnutrition affects more than half of SSc patients and is associated with specific cardiac involvement. Interincisal distance <35 mm could be a red flag for severe malnutrition in SSc.

Hospital-based surveillance of severe paediatric malaria in two malaria transmission ecological zones of Burkina Faso.

BACKGROUND: In the current context of tailoring interventions to maximize impact, it is important that current data of clinical epidemiology guide public health programmes and health workers in the management of severe disease. This study aimed at describing the burden of severe malaria at hospital level in two areas with distinct malaria transmission intensity. METHODS: A hospital-based surveillance was established in two regional hospitals located in two areas exposed to different malaria transmission. Data on paediatric severe malaria admissions were recorded using standardized methods from August 2017 to August 2018 with an interruption during the dry season from April to June 2018. RESULTS: In total, 921 children with severe malaria cases were enrolled in the study. The mean age was 33.9 (± 1.3) and 36.8 (± 1.6) months in lower malaria transmission (LMT) and higher malaria transmission (HMT) areas (p = 0.15), respectively. The geometric mean of asexual P. falciparum density was significantly higher in the LMT area compared to the HMT area: 22,861 trophozoites/µL (95% CI 17,009.2-30,726.8) vs 11,291.9 trophozoites/µL (95% CI 8577.9-14,864.5). Among enrolled cases, coma was present in 70 (9.2%) participants. 196 patients (21.8%) presented with two or more convulsions episodes prior to admission. Severe anaemia was present in 448 children (49.2%). Other clinical features recorded included 184 (19.9%) cases of lethargy, 99 (10.7%) children with incoercible vomiting, 80 (8.9%) patients with haemoglobinuria, 43 (4.8%) children with severe hypoglycaemia, 37 (4.0%) cases where child was unable to drink/suck, 11 (1.2%) cases of patients with circulatory collapse/shock, and 8 cases (0.9%) of abnormal bleeding (epistaxis). The adjusted odds of presenting with coma, respiratory distress, haemoglobinuria, circulatory collapse/shock and hypoglycaemia were significantly higher (respectively 6.5 (95%CI 3.4-12.1); 1.8 (95%CI 1.0-3.2); 2.7 (95%CI 1.6-4.3); 5.9 (95%CI 1.3-27.9); 1.9 (95%CI 1.0-3.6)) in children living in the HMT area compared to those residing in the LMT area. Overall, forty-four children died during hospitalization (case fatality rate 5.0%) with the highest fatalities in children admitted with respiratory distress (26.0%) and those with hypoglycaemia (25.0%). CONCLUSION: The study showed that children in the HMT area have a higher risk of presenting with coma, shock/dehydration, haemoglobinuria, hypoglycaemia, and respiratory distress. Case-fatality rate is higher among patients with respiratory distress or hypoglycaemia. Hospital surveillance provides a reliable and sustainable means to monitor the clinical presentation of severe malaria and tailor the training needs and resources allocation for case management.

Safety and immunogenicity of Vi-typhoid conjugate vaccine co-administration with routine 9-month vaccination in Burkina Faso: A randomized controlled phase 2 trial.

OBJECTIVES: In 2017, the World Health Organisation (WHO) pre-qualified a single-dose typhoid conjugate vaccine (TCV) and identified TCV co-administration studies as a research priority. Accordingly, we tested co-administration of Typbar TCV® (Bharat Biotech International) with measles-rubella (MR) and yellow fever (YF) vaccines. METHODS: We conducted a randomized, double-blind, and controlled, phase 2 trial in Ouagadougou, Burkina Faso. Healthy children aged 9-11 months were randomized 1:1 to receive TCV (Group 1) or control vaccine (inactivated polio vaccine (IPV), Group 2). Vaccines were administered intramuscularly with routine MR and YF vaccines. Safety was assessed by (1) local and systemic reactions on days 0, 3, and 7; (2) unsolicited adverse events within 28 days; and (3) serious adverse events (SAEs) within six months after immunization. RESULTS: We enrolled, randomized, and vaccinated 100 eligible children (49 Group 1 and 51 Group 2). Safety outcomes occurred with similar frequency in both groups: local/solicited reactions (Group 1: 1/49, Group 2: 3/50), systemic/solicited reactions (Group 1: 4/49, Group 2: 9/50), unsolicited adverse events (Group 1: 26/49, Group 2: 33/51), and SAEs (Group 1: 2/49, Group 2: 3/51). TCV conferred robust immunogenicity without interference with MR or YF vaccines. CONCLUSION: TCV can be safely co-administered with MR and YF vaccines to children at the 9-month vaccination visit.

Safety and immunogenicity of co-administration of meningococcal type A and measles-rubella vaccines with typhoid conjugate vaccine in children aged 15-23 months in Burkina Faso.

OBJECTIVES: The World Health Organization pre-qualified single-dose typhoid conjugate vaccine (TCV) and requested data on co-administration with routine vaccines. The co-administration of Typbar TCV (Bharat Biotech International) with routine group A meningococcal conjugate vaccine (MCV-A) and measles-rubella (MR) vaccine was tested. METHODS: This was a double-blind, randomized controlled trial performed in Ouagadougou, Burkina Faso. Children were recruited at the 15-month vaccination visit and were assigned randomly (1:1:1) to three groups. Group 1 children received TCV plus control vaccine (inactivated polio vaccine) and MCV-A 28 days later; group 2 children received TCV and MCV-A; group 3 children received MCV-A and control vaccine. Routine MR vaccine was administered to all participants. Safety was assessed at 0, 3, and 7 days after immunization, and unsolicited adverse events and serious adverse events were assessed for 28 days and 6 months after immunization, respectively. RESULTS: A total of 150 children were recruited and vaccinated. Solicited symptoms were infrequent and similar for TCV and control recipients, as were adverse events (group 1, 61.2%; group 2, 64.0%; group 3, 68.6%) and serious adverse events (group 1, 2.0%; group 2, 8.0%; group 3, 5.9%). TCV generated robust immunity without interference with MCV-A vaccine. CONCLUSIONS: TCV can be safely co-administered at 15 months with MCV-A without interference. This novel study on the co-administration of TCV with MCV-A provides data to support large-scale uptake in sub-Saharan Africa.

Iron in the General Population and Specificities in Older Adults: Metabolism, Causes and Consequences of Decrease or Overload, and Biological Assessment.

Iron is involved in many types of metabolism, including oxygen transport in hemoglobin. Iron deficiency (ID), ie a decrease in circulating iron, can have severe consequences. We provide an update on iron metabolism and ID, highlighting the particularities in older adults (OAs). There are three iron compartments in the human body: 1) the functional compartment, which consists of heme proteins including hemoglobin, myoglobin and respiratory enzymes; 2) iron reserves (IR), which consist mainly of liver stocks and are stored as ferritin; and 3) transferrin. There are two types of ID. Absolute ID is characterized by a decrease in IR. Its main pathophysiological mechanism is bleeding, which is often digestive and can be due to neoplasia, frequent in OAs. Biological assessment shows low serum ferritin and transferrin saturation (TS) levels. Furthermore, hypochromic microcytic anemia is frequent, and the serum-soluble transferrin receptor (sTfR) level is high. Functional ID, in which IR are high or normal, is due to inflammation, which is also frequent in OAs, particularly in its chronic form. Biological assessments show high serum ferritin, normal or low TS, and normal sTfR levels. Moreover, C-reactive protein is elevated, and there is moderate non-regenerative non-macrocytic anemia. The main characteristics of iron metabolism anomalies in the elderly are the high frequency of ID (20% of ID with anemia in adults ≥85 years) and the severity of its consequences, which include cognitive impairment in case of ID or iron overload and decrease of physical activity in case of ID. In conclusion, causes of ID are frequently intertwined in OAs as a result of the polymorbidity that characterizes them. ID can have dramatic consequences, especially in frail OAs. Thus, measuring the appropriate biological markers prevents errors in the positive diagnosis of ID type, clarifies etiology, and informs treatment-related decision-making.

Vasculitis associated with myelodysplastic syndrome and chronic myelomonocytic leukemia: French multicenter case-control study.

INTRODUCTION: Our objective was to evaluate characteristics, treatment and outcome of vasculitis associated with myelodysplastic syndrome (MDS) and chronic myelomonicytic leukemia (CMML) PATIENTS AND METHODS: Retrospective descriptive analysis of MDS/CMML-related vasculitis and comparison with MDS/CMML patients without dysimmune features. RESULTS: Seventy patients with vasculitis and MDS/CMML were included, with median age of 71.5 [21-90] years and male/female ratio of 2.3. Vasculitis was diagnosed prior to MDS/CMML in 31 patients (44%), and after in 20 patients. In comparison with MDS/CMML without autoimmune/inflammatory features, vasculitis with MDS/MPN showed no difference in MDS/CMML subtypes distribution nor International Prognostic Scoring System and CMML-specific prognostic (IPSS/CPSS) scores. Vasculitis subtypes included Giant cell arteritis in 24 patients (34%), Behçet's-like syndrome in 11 patients (20%) and polyarteritis nodosa in 6 patients (9%). Glucocorticoids (GCs) were used as first-line therapy for MDS/CMML vasculitis in 64/70 patients (91%) and 41 (59%) received combined immunosuppressive therapies during the follow-up. After a median follow-up of 33.2 months [1-162], 31 patients (44%) achieved sustained remission. At least one relapse occurred in 43 patients (61%). Relapse rates were higher in patients treated with conventional Disease Modifying Anti-Rheumatic Drug (DMARDs) (odds ratio 4.86 [95% CI 1.38 - 17.10]), but did not differ for biologics (odds ratio 0.59 [95% CI 0.11-3.20]) and azacytidine (odds ratio 1.44 [95% CI 0.21-9.76]) than under glucocorticoids. Overall survival in MDS/CMML vasculitis was not significantly different from MDS/CMML patients without autoimmune/inflammatory features (p = 0.5), but acute leukemia progression rates were decreased (log rank <0.05). CONCLUSION: This study shows no correlation of vasculitis diagnoses with subtypes and severity of MDS/CMML, and no significant impact of vasculitis on overall survival. Whereas conventional DMARDs seem to be less effective, biologics or azacytidine therapy could be considered for even low-risk MDS/CMML vasculitis.

The Plasmatic Aldosterone and C-Reactive Protein Levels, and the Severity of Covid-19: The Dyhor-19 Study.

BACKGROUND: The new coronavirus SARS-CoV-2, responsible for the Covid-19 pandemic, uses the angiotensin converting enzyme type 2 (ACE2), a physiological inhibitor of the renin angiotensin aldosterone system (RAAS), as a cellular receptor to infect cells. Since the RAAS can induce and modulate pro-inflammatory responses, it could play a key role in the pathophysiology of Covid-19. Thus, we aimed to determine the levels of plasma renin and aldosterone as indicators of RAAS activation in a series of consecutively admitted patients for Covid-19 in our clinic. METHODS: Plasma renin and aldosterone levels were measured, among the miscellaneous investigations needed for Covid-19 management, early after admission in our clinic. Disease severity was assessed using a seven-category ordinal scale. Primary outcome of interest was the severity of patients' clinical courses. RESULTS: Forty-four patients were included. At inclusion, 12 patients had mild clinical status, 25 moderate clinical status and 7 severe clinical status. In univariate analyses, aldosterone and C-reactive protein (CRP) levels at inclusion were significantly higher in patients with severe clinical course as compared to those with mild or moderate course (p < 0.01 and p = 0.03, respectively). In multivariate analyses, only aldosterone and CRP levels remained positively associated with severity. We also observed a positive significant correlation between aldosterone and CRP levels among patients with an aldosterone level greater than 102.5 pmol/L. CONCLUSIONS: Both plasmatic aldosterone and CRP levels at inclusion are associated with the clinical course of Covid-19. Our findings may open new perspectives in the understanding of the possible role of RAAS for Covid-19 outcome.

PRIMVAC vaccine adjuvanted with Alhydrogel or GLA-SE to prevent placental malaria: a first-in-human, randomised, double-blind, placebo-controlled study.

BACKGROUND: PRIMVAC is a VAR2CSA-derived placental malaria vaccine candidate aiming to prevent serious clinical outcomes of Plasmodium falciparum infection during pregnancy. We assessed the safety and immunogenicity of PRIMVAC adjuvanted with Alhydrogel or glucopyranosyl lipid adjuvant in stable emulsion (GLA-SE) in French and Burkinabe women who were not pregnant. METHODS: This first-in-human, randomised, double-blind, placebo-controlled, dose escalation trial was done in two staggered phases, a phase 1A trial in 18-35-year-old women who were malaria naive in a hospital in France and a subsequent phase 1B trial in women who were naturally exposed to P falciparum and nulligravid in the clinical site of a research centre in Burkina Faso. Volunteers were recruited into four sequential cohorts receiving PRIMVAC intramuscularly at day 0, 28, and 56: two cohorts in France receiving 20 µg or 50 µg of PRIMVAC and then two in Burkina Faso receiving 50 µg or 100 µg of PRIMVAC. Volunteers were randomly assigned (1:1) to two groups (PRIMVAC adjuvanted with either Alhydrogel or GLA-SE) in France and randomly assigned (2:2:1) to three groups (PRIMVAC adjuvanted with either Alhydrogel, GLA-SE, or placebo) in Burkina Faso. Randomisation was centralised, using stratification by cohort and blocks of variable size, and syringes were masked by opaque labels. The primary endpoint was the proportion of participants with any grade 3 or higher adverse reaction to vaccination up until day 35. Safety at later time points as well as humoral and cellular immunogenicity were assessed in secondary endpoints. This trial is registered with ClinicalTrials.gov, NCT02658253. FINDINGS: Between April 19, 2016, and July 13, 2017, 68 women (18 in France, 50 in Burkina Faso) of 101 assessed for eligibility were included. No serious adverse event related to the vaccine occurred. PRIMVAC antibody titres increased with each dose and seroconversion was observed in all women vaccinated with PRIMVAC (n=57). PRIMVAC antibody titres reached a peak (geometric mean 11 843·0, optical density [OD] 1·0, 95% CI 7559·8-18 552·9 with 100 µg dose and GLA-SE) 1 week after the third vaccination (day 63). Compared with Alhydrogel, GLA-SE tended to improve the PRIMVAC antibody response (geometric mean 2163·5, OD 1·0, 95% CI 1315·7-3557·7 with 100 µg dose and Alhydrogel at day 63). 1 year after the last vaccination, 20 (71%) of 28 women who were vaccinated with PRIMVAC/Alhydrogel and 26 (93%) of 28 women who were vaccinated with PRIMVAC/GLA-SE still had anti-PRIMVAC antibodies, although antibody magnitude was markedly lower (452·4, OD 1·0, 95% CI 321·8-636·1 with 100 µg dose and GLA-SE). These antibodies reacted with native homologous VAR2CSA expressed by NF54-CSA infected erythrocytes (fold change from baseline at day 63 with 100 µg dose and GLA-SE: 10·74, 95% CI 8·36-13·79). Limited cross-recognition, restricted to sera collected from women that received the 100 µg PRIMVAC dose, was observed against heterologous VAR2CSA variants expressed by FCR3-CSA (fold change from baseline at day 63: 1·49, 95% CI 1·19-1·88) and 7G8-CSA infected erythrocytes (1·2, 1·08-1·34). INTERPRETATION: PRIMVAC adjuvanted with Alhydrogel or GLA-SE had an acceptable safety profile, was immunogenic, and induced functional antibodies reacting with the homologous VAR2CSA variant expressed by NF54-CSA infected erythrocytes. Cross-reactivity against heterologous VAR2CSA variants was limited and only observed in the higher dose group. An alternate schedule of immunisation, antigen dose, and combinations with other VAR2CSA-based vaccines are envisaged to improve the cross-reactivity against heterologous VAR2CSA variants. FUNDING: Bundesministerium für Bildung und Forschung, through Kreditanstalt für Wiederaufbau, Germany; Inserm, and Institut National de Transfusion Sanguine, France; Irish Aid, Department of Foreign Affairs and Trade, Ireland.

Characteristics, outcome and treatments with cranial pachymeningitis: A multicenter French retrospective study of 60 patients.

The aim of this study was to determine the characteristics, treatment, and outcome according to each etiology of pachymeningitis.We conducted a retrospective multicenter French nationwide study between 2000 and 2016 to describe the characteristics, outcome, and treatment of pachymeningitis.We included 60 patients (median age 55.5 years; interquartile range [IQR] 30-80, female/male ratio 0.43). Neurologic signs were present in 59 patients (98%) and consisted of headache in 43 (72%), cranial nerve palsy in 33 (55%), confusion in 10 (17%), seizures in 7 (12%), and focal neurologic signs in 9 (15%). Fever and weight loss were present in 8 (13%) and 13 cases (22%), respectively. Cerebral venous thrombosis was present in 8 cases (13%). Analysis of cerebrospinal fluid showed moderate hyperproteinorachia (median 0.68 g/L; IQR 0.46-3.2) with or without pleiocytosis. Diagnosis included idiopathic pachymeningitis (n = 18; 30%); granulomatosis with polyangiitis (n = 13; 17%); Erdheim-Chester disease (n = 10; 17%); IgG4-related disease and tuberculosis (n = 3; 5% each); Rosai-Dofman disease, microscopic polyangiitis, and sarcoidosis (n = 2, 3% each); cryptococcal meningitis, Lyme disease, ear-nose-throat infection, postlumbar puncture, low spinal-fluid pressure syndrome, and lymphoma (n = 1 each). We found no difference in demographics and neurologic presentation among idiopathic pachymeningitis, Erdheim-Chester disease, and granulomatosis with polyangiitis. In contrast, frequencies were lower with idiopathic pachymeningitis than Erdheim-Chester disease for general signs (6% and 40%, respectively, P = .041) and complete neurologic response (0% vs 39%, P = .045).The detection of extraneurologic signs and routine screening are needed to classify the pachymeningitis origin. Prospective studies are warranted to determine the best treatment in each case.

Efficacy and safety of biologics in relapsing polychondritis: a French national multicentre study.

OBJECTIVES: To assess the efficacy and the safety of biologics in a cohort of patients with relapsing polychondritis (RP). METHODS: We conducted a French multicentre retrospective cohort study including patients treated with biologics for RP. Efficacy outcomes were clinical response (partial or complete) and complete response during the first 6 months of exposure, plus daily corticosteroid dose at 6 months. Other outcomes were adverse drug reactions (ADRs), persistence of biologics and factors associated with a response. RESULTS: This study included 41 patients exposed to 105 biologics (tumour-necrosis factor (TNF) inhibitors, n=60; tocilizumab, n=17; anakinra, n=15; rituximab, n=7; abatacept, n=6). Overall response rate during the first 6 months of exposure was 62.9%. Complete response rate was 19.0%. Reduced corticosteroid doses were highly variable among patients. ADRs were mostly infections (n=42). Reasons for biologic withdrawal (73.3%) were insufficient efficacy (34.3%; ranging from 23.5% for tocilizumab to 72.7% for etanercept), loss of efficacy (18.1%) and ADRs (20.9%; mostly for anakinra: 46.7%). Persistence was comparable among biologic classes. Among TNF inhibitors, the highest persistence was observed with adalimumab. Differences in clinical response rates were observed depending on biologics and organ involvement. There were trends towards a lower response rate in cases with associated myelodysplastic syndrome and for a higher response rate for nasal/auricular chondritis, sternal chondritis and concomitant exposure to non-biologic disease-modifying antirheumatic drugs. CONCLUSIONS: This study describes the efficacy of biologics for refractory RP. However, the number of complete responses was low and there were concerns about the risk of ADRs, particularly infections.

Antibody responses to P. falciparum blood stage antigens and incidence of clinical malaria in children living in endemic area in Burkina Faso.

BACKGROUND: High parasite-specific antibody levels are generally associated with low susceptibility to Plasmodium falciparum malaria. This has been supported by several studies in which clinical malaria cases of P. falciparum malaria were reported to be associated with low antibody avidities. This study was conducted to evaluate the role of age, malaria transmission intensity and incidence of clinical malaria in the induction of protective humoral immune response against P. falciparum malaria in children living in Burkina Faso. METHODS: We combined levels of IgG and IgG subclasses responses to P. falciparum antigens: Merozoite Surface Protein 3 (MSP3), Merozoite Surface Protein 2a (MSP2a), Merozoite Surface Protein 2b (MSP2b), Glutamate Rich Protein R0 (GLURP R0) and Glutamate Rich Protein R2 (GLURP R2) in plasma samples from 325 children under five (05) years with age, malaria transmission season and malaria incidence. RESULTS: We notice higher prevalence of P. falciparum infection in low transmission season compared to high malaria transmission season. While, parasite density was lower in low transmission than high transmission season. IgG against all antigens investigated increased with age. High levels of IgG and IgG subclasses to all tested antigens except for GLURP R2 were associated with the intensity of malaria transmission. IgG to MSP3, MSP2b, GLURP R2 and GLURP R0 were associated with low incidence of malaria. All IgG subclasses were associated with low incidence of P. falciparum malaria, but these associations were stronger for cytophilic IgGs. CONCLUSIONS: On the basis of the data presented in this study, we conclude that the induction of humoral immune response to tested malaria antigens is related to age, transmission season level and incidence of clinical malaria.

Clinical Variation of Plasmodium falciparum eba-175, ama-1, and msp-3 Genotypes in Young Children Living in a Seasonally High Malaria Transmission Setting in Burkina Faso.

The association between P. falciparum eba-175, ama-1, and msp-3 polymorphism in the pathogenicity of malaria disease was investigated. We therefore compared the prevalence of different alleles between symptomatic and asymptomatic malarial children under five years of age living in Burkina Faso. Blood filter papers were collected during the 2008 malaria transmission season from 228 symptomatic and 199 asymptomatic children under five years of age. All patients were living in the rural area of Saponé at about 50 km from Ouagadougou, the capital city of Burkina Faso. P. falciparum parasite DNA was extracted using QIAGEN kits and the alleles diversity was assessed by a nested PCR. PCR products were then digested by restriction enzymes based on already described polymorphic regions of the eba-175, ama-1, and msp-3 genes. The individual alleles eba-175_FCR3 and msp-3_K1 frequencies were statistically higher (p < 0.0001) in the asymptomatic group compared to the symptomatic ones. No statistically significant difference was noted in the prevalence of ama-1-3D7, ama-1-K1, and ama-1-HB3 genotypes between the two groups (p > 0.05). The comparative analysis of P. falciparum genotypes indicated that the polymorphism in eba-175 and msp-3 genotypes varied between asymptomatic and symptomatic clinical groups and may contribute to the pathogenesis of malaria.

Analysis of Preventive Interventions for Malaria: Exploring Partial and Complete Protection and Total and Primary Intervention Effects.

Event dependence, the phenomenon in which future risk depends on past disease history, is not commonly accounted for in the statistical models used by malaria researchers. However, recently developed methods for the analysis of repeated events allow this to be done, while also accounting for heterogeneity in risk and nonsusceptible subgroups. Accounting for event dependence allows separation of the primary effect of an intervention from its total effect, which is composed of its primary effect on risk of disease and its secondary effect mediated by event dependence. To illustrate these methods and show the insights they can provide, we have reanalyzed 2 trials of seasonal malaria chemoprevention (SMC) in Boussé, Burkina Faso, and Kati, Mali, in 2008-2009, as well as a trial of intermittent preventive treatment of malaria in infants in Navrongo, Ghana, in 2000-2004. SMC completely protects a large fraction of recipients, while intermittent preventive treatment in infants provides modest partial protection, consistent with the rationale of these 2 different chemopreventive approaches. SMC has a primary effect that is substantially greater than the total effect previously estimated by trials, with the lower total effect mediated by negative event dependence. These methods contribute to an understanding of the mechanisms of protection from these interventions and could improve understanding of other tools to control malaria, including vaccines.

Lessons learned from the use of HRP-2 based rapid diagnostic test in community-wide screening and treatment of asymptomatic carriers of Plasmodium falciparum in Burkina Faso.

BACKGROUND: Rapid diagnostic tests (RDTs) are immune chromatographic tests targeting antigens of one or more Plasmodium species and offer the potential to extend accurate malaria diagnosis in endemic areas. In this study, the performance of Plasmodium falciparum-specific histidine-rich protein-2 (PfHRP-2) RDT in the detection of asymptomatic carriers from a hyperendemic region of Burkina Faso was compared with microscopy to gain further insight on its relevance in community-based interventions. METHODS: The performance of HRP-2 test was evaluated in terms of sensitivity, specificity, positive and negative predictive values, discordant values, likelihood ratios, accuracy, and precision using microscopy as the 'gold standard'. This analysis was carried out in a controlled, parallel, cluster-randomized (18 clusters; 1:1) study in children and adults. The effect of systematic treatment of P. falciparum asymptomatic carriers during three consecutive monthly community screening campaigns on the incidence of symptomatic malaria episodes over a 12-month period was compared with no treatment of asymptomatic carriers. RESULTS: Sensitivity of HRP-2 test in asymptomatic carriers was higher in campaign 1 (92.4%) when compared to campaign 2 (84.0%) and campaign 3 (77.8%). The sensitivity of HRP-2 test increased as parasite density increased across all the age groups. Highest sensitivity (≥97.0%) was recorded at parasite densities of 1,000-4,999/µl, except for children aged 10 to 14 years. The specificity of HRP-2 test was comparable across age groups and highest in campaign 3 (95.9%). The negative predictive values were high across the three campaigns (≥92.7%) while the positive predictive values ranged from 23.2 to 73.8%. False-positive and false-negative rates were high in campaign 1 and campaign 3, respectively. CONCLUSION: The performance of HRP-2 test in detecting asymptomatic carriers of P. falciparum varied by age and parasite density. Although the use of HRP-2 test is beneficial for the diagnosis of acute malaria, its low sensitivity in screening asymptomatic carriers may limit its utility in pre-elimination interventional settings. The use of a practical and more sensitive test such as loop-mediated isothermal amplification in combination with a cost effective HRP-2 test may be worth exploring in such settings.

A phase 1b randomized, controlled, double-blinded dosage-escalation trial to evaluate the safety, reactogenicity and immunogenicity of an adenovirus type 35 based circumsporozoite malaria vaccine in Burkinabe healthy adults 18 to 45 years of age.

BACKGROUND: Ad35.CS.01 is a pre-erythrocytic malaria candidate vaccine. It is a codon optimized nucleotide sequence representing the P. falciparum circumsporozoite (CS) surface antigen inserted in a replication deficient Adenovirus 35 backbone. A Phase 1a trial has been conducted in the USA in naïve adults and showed that the vaccine was safe. The aim of this study is to assess the safety and immunogenicity of ascending dosages in sub Saharan Africa. METHODS: A double blind, randomized, controlled, dose escalation, phase Ib trial was conducted in a rural area of Balonghin, the Saponé health district (Burkina Faso). Forty-eight healthy adults aged 18-45 years were randomized into 4 cohorts of 12 to receive three vaccine doses (day 0, 28 and 84) of 10(9), 10(10), 5X10(10), 10(11) vp of Ad35.CS.01 or normal saline by intra muscular injection. Subjects were monitored carefully during the 14 days following each vaccination for non serious adverse events. Severe and serious adverse events were collected throughout the participant study duration (12 months from the first vaccination). Humoral and cellular immune responses were measured on study days 0, 28, 56, 84, 112 and 140. RESULTS: Of the forty-eight subjects enrolled, forty-four (91.7%) received all three scheduled vaccine doses. Local reactions, all of mild severity, occurred in thirteen (27.1%) subjects. Severe (grade 3) laboratory abnormalities occurred in five (10.4%) subjects. One serious adverse event was reported and attributed to infection judged unrelated to vaccine. The vaccine induced both antibody titers and CD8 T cells producing IFNγ and TNFα with specificity to CS while eliciting modest neutralizing antibody responses against Ad35. CONCLUSION: Study vaccine Ad35.CS.01 at four different dose levels was well-tolerated and modestly immunogenic in this population. These results suggest that Ad35.CS.01 should be further investigated for preliminary efficacy in human challenge models and as part of heterologous prime-boost vaccination strategies. TRIAL REGISTRATION: ClinicalTrials.gov NCT01018459 http://clinicaltrials.gov/ct2/show/NCT01018459.

Variation in haematological parameters in children less than five years of age with asymptomatic Plasmodium infection: implication for malaria field studies.

During the season of high malaria transmission, most children are infected by Plasmodium, which targets red blood cells (RBCs), affecting haematological parameters. To describe these variations, we examined the haematological profiles of two groups of children living in a malaria-endemic area. A cross-sectional survey was conducted at the peak of the malaria transmission season in a rural area of Burkina Faso. After informed consent and clinical examination, blood samples were obtained from the participants for malaria diagnosis and a full blood count. Of the 414 children included in the analysis, 192 were not infected with Plasmodium, whereas 222 were asymptomatic carriers of Plasmodium infection. The mean age of the infected children was 41.8 months (range of 26.4-57.2) compared to 38.8 months (range of 22.4-55.2) for the control group (p = 0.06). The asymptomatic infected children tended to have a significantly lower mean haemoglobin level (10.8 g/dL vs. 10.4 g/dL; p < 0.001), mean lymphocyte count (4592/µL vs. 5141/µL; p = 0.004), mean platelet count (266 x 10³/µL vs. 385 x 10³/µL; p < 0.001) and mean RBC count (4.388 x 10(6)/µL vs. 4.158 x 10(6)/µL; p < 0.001) and a higher mean monocyte count (1403/µL vs. 1192/µL; p < 0.001) compared to the control group. Special attention should be applied when interpreting haematological parameters and evaluating immune responses in asymptomatic infected children living in malaria-endemic areas and enrolled in vaccine trials.

Variation in haematological parameters in children less than five years of age with asymptomatic Plasmodium infection: implication for malaria field studies

During the season of high malaria transmission, most children are infected by Plasmodium, which targets red blood cells (RBCs), affecting haematological parameters. To describe these variations, we examined the haematological profiles of two groups of children living in a malaria-endemic area. A cross-sectional survey was conducted at the peak of the malaria transmission season in a rural area of Burkina Faso. After informed consent and clinical examination, blood samples were obtained from the participants for malaria diagnosis and a full blood count. Of the 414 children included in the analysis, 192 were not infected with Plasmodium, whereas 222 were asymptomatic carriers of Plasmodium infection. The mean age of the infected children was 41.8 months (range of 26.4-57.2) compared to 38.8 months (range of 22.4-55.2) for the control group (p = 0.06). The asymptomatic infected children tended to have a significantly lower mean haemoglobin level (10.8 g/dL vs. 10.4 g/dL; p < 0.001), mean lymphocyte count (4592/µL vs. 5141/µL; p = 0.004), mean platelet count (266 x 103/µL vs. 385 x 103/µL; p < 0.001) and mean RBC count (4.388 x 106/µL vs. 4.158 x 106/µL; p < 0.001) and a higher mean monocyte count (1403/µL vs. 1192/µL; p < 0.001) compared to the control group. Special attention should be applied when interpreting haematological parameters and evaluating immune responses in asymptomatic infected children living in malaria-endemic areas and enrolled in vaccine trials.

Malaria morbidity in high and seasonal malaria transmission area of Burkina Faso.

BACKGROUND: Malariometric parameters are often primary endpoints of efficacy trials of malaria vaccine candidates. This study aims to describe the epidemiology of malaria prior to the conduct of a series of drug and vaccine trials in a rural area of Burkina Faso. METHODS: Malaria incidence was prospectively evaluated over one year follow-up among two cohorts of children aged 0-5 years living in the Saponé health district. The parents of 1089 children comprising a passive case detection cohort were encouraged to seek care from the local health clinic at any time their child felt sick. Among this cohort, 555 children were randomly selected for inclusion in an active surveillance sub-cohort evaluated for clinical malaria during twice weekly home visits. Malaria prevalence was evaluated by cross-sectional survey during the low and high transmission seasons. RESULTS: Number of episodes per child ranged from 0 to 6 per year. Cumulative incidence was 67.4% in the passive and 86.2% in the active cohort and was highest among children 0-1 years. Clinical malaria prevalence was 9.8% in the low and 13.0% in the high season (p>0.05). Median days to first malaria episode ranged from 187 (95% CI 180-193) among children 0-1 years to 228 (95% CI 212, 242) among children 4-5 years. The alternative parasite thresholds for the malaria case definition that achieved optimal sensitivity and specificity (70-80%) were 3150 parasites/µl in the high and 1350 parasites/µl in the low season. CONCLUSION: Clinical malaria burden was highest among the youngest age group children, who may represent the most appropriate target population for malaria vaccine candidate development. The pyrogenic threshold of parasitaemia varied markedly by season, suggesting a value for alternative parasitaemia levels in the malaria case defintion. Regional epidemiology of malaria described, Sapone area field centers are positioned for future conduct of malaria vaccine trials.