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1.
Lancet ; 403(10439): 1879-1892, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38697170

RESUMO

BACKGROUND: Microneedle patches (MNPs) have been ranked as the highest global priority innovation for overcoming immunisation barriers in low-income and middle-income countries. This trial aimed to provide the first data on the tolerability, safety, and immunogenicity of a measles and rubella vaccine (MRV)-MNP in children. METHODS: This single-centre, phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial was conducted in The Gambia. To be eligible, all participants had to be healthy according to prespecified criteria, aged 18-40 years for the adult cohort, 15-18 months for toddlers, or 9-10 months for infants, and to be available for visits throughout the follow-up period. The three age cohorts were randomly assigned in a 2:1 ratio (adults) or 1:1 ratio (toddlers and infants) to receive either an MRV-MNP (Micron Biomedical, Atlanta, GA, USA) and a placebo (0·9% sodium chloride) subcutaneous injection, or a placebo-MNP and an MRV subcutaneous injection (MRV-SC; Serum Institute of India, Pune, India). Unmasked staff ransomly assigned the participants using an online application, and they prepared visually identical preparations of the MRV-MNP or placebo-MNP and MRV-SC or placebo-SC, but were not involved in collecting endpoint data. Staff administering the study interventions, participants, parents, and study staff assessing trial endpoints were masked to treatment allocation. The safety population consists of all vaccinated participants, and analysis was conducted according to route of MRV administration, irrespective of subsequent protocol deviations. The immunogenicity population consisted of all vaccinated participants who had a baseline and day 42 visit result available, and who had no protocol deviations considered to substantially affect the immunogenicity endpoints. Solicited local and systemic adverse events were collected for 14 days following vaccination. Unsolicited adverse events were collected to day 180. Age de-escalation between cohorts was based on the review of the safety data to day 14 by an independent data monitoring committee. Serum neutralising antibodies to measles and rubella were measured at baseline, day 42, and day 180. Analysis was descriptive and included safety events, seroprotection and seroconversion rates, and geometric mean antibody concentrations. The trial was registered with the Pan African Clinical Trials Registry PACTR202008836432905, and is complete. FINDINGS: Recruitment took place between May 18, 2021, and May 27, 2022. 45 adults, 120 toddlers, and 120 infants were randomly allocated and vaccinated. There were no safety concerns in the first 14 days following vaccination in either adults or toddlers, and age de-escalation proceeded accordingly. In infants, 93% (52/56; 95% CI 83·0-97·2) seroconverted to measles and 100% (58/58; 93·8-100) seroconverted to rubella following MRV-MNP administration, while 90% (52/58; 79·2-95·2) and 100% (59/59; 93·9-100) seroconverted to measles and rubella respectively, following MRV-SC. Induration at the MRV-MNP application site was the most frequent local reaction occurring in 46 (77%) of 60 toddlers and 39 (65%) of 60 infants. Related unsolicited adverse events, most commonly discolouration at the application site, were reported in 35 (58%) of 60 toddlers and 57 (95%) of 60 infants that had received the MRV-MNP. All local reactions were mild. There were no related severe or serious adverse events. INTERPRETATION: The safety and immunogenicity data support the accelerated development of the MRV-MNP. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Vacina contra Sarampo , Vacina contra Rubéola , Rubéola (Sarampo Alemão) , Humanos , Método Duplo-Cego , Gâmbia , Feminino , Masculino , Vacina contra Rubéola/administração & dosagem , Vacina contra Rubéola/imunologia , Vacina contra Rubéola/efeitos adversos , Lactente , Vacina contra Sarampo/administração & dosagem , Vacina contra Sarampo/imunologia , Adulto , Adolescente , Rubéola (Sarampo Alemão)/prevenção & controle , Adulto Jovem , Sarampo/prevenção & controle , Agulhas , Anticorpos Antivirais/sangue
2.
Malar J ; 23(1): 100, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589884

RESUMO

BACKGROUND: Anopheles gambiae, the major malaria mosquito in sub-Saharan Africa, feed largely indoors at night. Raising a house off the ground with no barriers underneath reduces mosquito-house entry. This experiment tested whether walling off the space under an elevated hut affects mosquito-hut entry. METHODS: Four inhabited experimental huts, each of which could be moved up and down, were used in rural Gambia. Nightly collections of mosquitoes were made using light traps and temperature and carbon dioxide levels monitored indoors and outdoors using loggers. Each night, a reference hut was kept at ground level and three huts raised 2 m above the ground; with the space under the hut left open, walled with air-permeable walls or solid walls. Treatments were rotated every four nights using a randomized block design. The experiment was conducted for 32 nights. Primary measurements were mosquito numbers and indoor temperature in each hut. RESULTS: A total of 1,259 female Anopheles gambiae sensu lato were collected in the hut at ground level, 655 in the hut with an open ground floor, 981 in the hut with air-permeable walls underneath and 873 in the hut with solid walls underneath. Multivariate analysis, adjusting for confounders, showed that a raised hut open underneath had 53% fewer mosquitoes (95% CI 47-58%), those with air-permeable walls underneath 24% fewer (95% CI 9-36%) and huts with solid walls underneath 31% fewer (95% CI 24-37%) compared with a hut on the ground. Similar results were found for Mansonia spp. and total number of female mosquitoes, but not for Culex mosquitoes where hut entry was unaffected by height or barriers. Indoor temperature and carbon dioxide levels were similar in all huts. CONCLUSION: Raising a house 2 m from the ground reduces the entry of An. gambiae and Mansonia mosquitoes, but not Culex species. The protective effect of height is reduced if the space underneath the hut is walled off.


Assuntos
Anopheles , Culex , Inseticidas , Animais , Feminino , Gâmbia , Dióxido de Carbono/farmacologia , Controle de Mosquitos/métodos , Mosquitos Vetores , Inseticidas/farmacologia
3.
J Antimicrob Chemother ; 77(11): 2946-2955, 2022 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-35904009

RESUMO

BACKGROUND: Artemether/lumefantrine is the most commonly used artemisinin-based combination treatment (ACT) for malaria in sub-Saharan Africa. Drug resistance to ACT components is a major threat to malaria elimination efforts. Therefore, rigorous monitoring of drug efficacy is required for adequate management of malaria and to sustain the effectiveness of ACTs. OBJECTIVES: This study identified and described genomic loci that correlate with differences in ex vivo responses of natural Plasmodium falciparum isolates from The Gambia to antimalarial drugs. METHODS: Natural P. falciparum isolates from The Gambia were assayed for IC50 responses to four antimalarial drugs (artemether, dihydroartemisinin, amodiaquine and lumefantrine). Genome-wide SNPs from 56 of these P. falciparum isolates were applied to mixed-model regression and network analyses to determine linked loci correlating with drug responses. Genomic regions of shared haplotypes and positive selection within and between Gambian and Cambodian P. falciparum isolates were mapped by identity-by-descent (IBD) analysis of 209 genomes. RESULTS: SNPs in 71 genes, mostly involved in stress and drug resistance mechanisms correlated with drug responses. Additionally, erythrocyte invasion and permeability loci, including merozoite surface proteins (Pfdblmsp, Pfsurfin), and high-molecular-weight rhoptry protein 2 (Pfrhops2) were correlated with responses to multiple drugs. Haplotypes of pfdblmsp2 and known drug resistance loci (pfaat1, pfcrt and pfdhfr) from The Gambia showed high IBD with those from Cambodia, indicating co-ancestry, with significant linkage disequilibrium between their alleles. CONCLUSIONS: Multiple linked genic loci correlating with drug response phenotypes suggest a genomic backbone may be under selection by antimalarials. This calls for further analysis of molecular pathways to drug resistance in African P. falciparum.


Assuntos
Antimaláricos , Malária Falciparum , Malária , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Plasmodium falciparum/genética , Merozoítos , Gâmbia , Ligantes , Artemeter/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Malária Falciparum/tratamento farmacológico , Lumefantrina/uso terapêutico , Resistência a Medicamentos/genética , Malária/tratamento farmacológico , Proteínas de Protozoários/genética
4.
Proc Natl Acad Sci U S A ; 116(34): 17121-17126, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31399544

RESUMO

Understanding the mechanisms of vaccine-elicited protection contributes to the development of new vaccines. The emerging field of systems vaccinology provides detailed information on host responses to vaccination and has been successfully applied to study the molecular mechanisms of several vaccines. Long noncoding RNAs (lncRNAs) are crucially involved in multiple biological processes, but their role in vaccine-induced immunity has not been explored. We performed an analysis of over 2,000 blood transcriptome samples from 17 vaccine cohorts to identify lncRNAs potentially involved with antibody responses to influenza and yellow fever vaccines. We have created an online database where all results from this analysis can be accessed easily. We found that lncRNAs participate in distinct immunological pathways related to vaccine-elicited responses. Among them, we showed that the expression of lncRNA FAM30A was high in B cells and correlates with the expression of immunoglobulin genes located in its genomic vicinity. We also identified altered expression of these lncRNAs in RNA-sequencing (RNA-seq) data from a cohort of children following immunization with intranasal live attenuated influenza vaccine, suggesting a common role across several diverse vaccines. Taken together, these findings provide evidence that lncRNAs have a significant impact on immune responses induced by vaccination.


Assuntos
Linfócitos B/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Vacinas contra Influenza/administração & dosagem , RNA Longo não Codificante/imunologia , Vacinação , Administração Intranasal , Pré-Escolar , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Humanos , Vacinas contra Influenza/imunologia , Masculino , Análise de Sequência de RNA
5.
Malar J ; 17(1): 227, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29879981

RESUMO

Unfortunately, the original article [1] contained an error mistakenly carried forward by the Production department handling this article whereby some figures and their captions were interchanged. The correct figures (Figs. 1, 2, 3, 4, 5) and captions are presented in this erratum. The original article has also been updated to reflect this correction.

6.
Malar J ; 17(1): 205, 2018 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-29776361

RESUMO

BACKGROUND: Insecticide resistance threatens malaria control in sub-Saharan Africa. Knockdown resistance to pyrethroids and organochlorines in Anopheles gambiae sensu lato (s.l.) is commonly caused by mutations in the gene encoding a voltage-gated sodium channel which is the target site for the insecticide. The study aimed to examine risk factors for knockdown resistance in An. gambiae s.l. and its relationship with malaria infection in children in rural Gambia. Point mutations at the Vgsc-1014 locus, were measured in An. gambiae s.l. during a 2-year trial. Cross-sectional surveys were conducted at the end of the transmission season to measure malaria infection in children aged 6 months-14 years. RESULTS: Whilst few Anopheles arabiensis and Anopheles coluzzii had Vgsc-1014 mutations, the proportion of An. gambiae sensu stricto (s.s.) mosquitoes homozygous for the Vgsc-1014F mutation increased from 64.8 to 90.9% during the study. The Vgsc-1014S or 1014F mutation was 80% higher in 2011 compared to 2010, and 27% higher in the villages with indoor residual spraying compared to those without. An increase in the proportion of An. gambiae s.l. mosquitoes with homozygous Vgsc-1014F mutations and an increase in the proportion of An. gambiae s.s. in a cluster were each associated with increased childhood malaria infection. Homozygous Vgsc-1014F mutations were, however, most common in An. gambiae s.s. and almost reached saturation during the study meaning that the two variables were colinear. CONCLUSIONS: As a result of colinearity between homozygous Vgsc-1014F mutations and An. gambiae s.s., it was not possible to determine whether insecticide resistance or species composition increased the risk of childhood malaria infection.


Assuntos
Anopheles/efeitos dos fármacos , Proteínas de Insetos/genética , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Malária/epidemiologia , Adolescente , Animais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Gâmbia/epidemiologia , Variação Genética , Humanos , Lactente , Proteínas de Insetos/metabolismo , Malária/parasitologia , Masculino , Prevalência , Especificidade da Espécie
8.
Lancet ; 385(9976): 1436-46, 2015 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-25498847

RESUMO

BACKGROUND: Although many malaria control programmes in sub-Saharan Africa use indoor residual spraying with long-lasting insecticidal nets (LLINs), the two studies assessing the benefit of the combination of these two interventions gave conflicting results. We aimed to assess whether the addition of indoor residual spraying to LLINs provided a significantly different level of protection against clinical malaria in children or against house entry by vector mosquitoes. METHODS: In this two-arm cluster, randomised, controlled efficacy trial we randomly allocated clusters of Gambian villages using a computerised algorithm to LLINs alone (n=35) or indoor residual spraying with dichlorodiphenyltrichloroethane plus LLINs (n=35). In each cluster, 65-213 children, aged 6 months to 14 years, were surveyed at the start of the 2010 transmission season and followed in 2010 and 2011 by passive case detection for clinical malaria. Exposure to parasite transmission was assessed by collection of vector mosquitoes with both light and exit traps indoors. Primary endpoints were the incidence of clinical malaria assessed by passive case detection and number of Anopheles gambiae sensu lato mosquitoes collected per light trap per night. Intervention teams had no role in data collection and the data collection teams were not informed of the spray status of villages. The trial is registered at the ISRCTN registry, number ISRCTN01738840. FINDINGS: LLIN coverage in 2011 was 3510 (93%) of 3777 children in the indoor residual spraying plus LLIN group and 3622 (95.5%) of 3791 in the LLIN group. In 2010, 7845 children were enrolled, 7829 completed passive case detection, and 7697 (98%) had complete clinical and covariate data. In 2011, 7009 children remained in the study, 648 more were enrolled, 7657 completed passive case detection, and 7545 (98.5%) had complete data. Indoor residual spraying coverage per cluster was more than 80% for both years in the indoor residual spraying plus LLIN group. Incidence of clinical malaria was 0.047 per child-month at risk in the LLIN group and 0.044 per child-month at risk in the indoor residual spraying plus LLIN group in 2010, and 0.032 per child-month at risk in the LLIN group and 0.034 per child-month at risk in the indoor residual spraying plus LLIN group in 2011. The incident rate ratio was 1.08 (95% CI 0.80-1.46) controlling for confounders and cluster by mixed-effect negative binomial regression on all malaria attacks for both years. No significant difference was recorded in the density of vector mosquitoes caught in light traps in houses over the two transmission seasons; the mean number of A gambiae sensu lato mosquitoes per trap per night was 6.7 (4.0-10.1) in the LLIN group and 4.5 (2.4-7.4) in the indoor residual spraying plus LLIN group (p=0.281 in the random-effects linear regression model). INTERPRETATION: We identified no significant difference in clinical malaria or vector density between study groups. In this area with high LLIN coverage, moderate seasonal transmission, and susceptible vectors, indoor residual spraying did not provide additional benefit. FUNDING: UK Medical Research Council.


Assuntos
Diclorodifenil Dicloroetileno/administração & dosagem , Mosquiteiros Tratados com Inseticida , Inseticidas/administração & dosagem , Malária/prevenção & controle , Adolescente , Algoritmos , Animais , Anopheles/efeitos dos fármacos , Criança , Pré-Escolar , Feminino , Gâmbia , Humanos , Lactente , Malária/transmissão , Masculino , Controle de Mosquitos/métodos
9.
Bull World Health Organ ; 94(6): 433-41, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27274595

RESUMO

OBJECTIVE: To estimate the population prevalence of active pulmonary tuberculosis in Gambia. METHODS: Between December 2011 and January 2013, people aged ≥ 15 years participating in a nationwide, multistage cluster survey were screened for active pulmonary tuberculosis with chest radiography and for tuberculosis symptoms. For diagnostic confirmation, sputum samples were collected from those whose screening were positive and subjected to fluorescence microscopy and liquid tuberculosis cultures. Multiple imputation and inverse probability weighting were used to estimate tuberculosis prevalence. FINDINGS: Of 100 678 people enumerated, 55 832 were eligible to participate and 43 100 (77.2%) of those participated. A majority of participants (42 942; 99.6%) were successfully screened for symptoms and by chest X-ray. Only 5948 (13.8%) were eligible for sputum examination, yielding 43 bacteriologically confirmed, 28 definite smear-positive and six probable smear-positive tuberculosis cases. Chest X-ray identified more tuberculosis cases (58/69) than did symptoms alone (43/71). The estimated prevalence of smear-positive and bacteriologically confirmed pulmonary tuberculosis were 90 (95% confidence interval, CI: 53-127) and 212 (95% CI: 152-272) per 100 000 population, respectively. Tuberculosis prevalence was higher in males (333; 95% CI: 233-433) and in the 35-54 year age group (355; 95% CI: 219-490). CONCLUSION: The burden of tuberculosis remains high in Gambia but lower than earlier estimates of 490 per 100 000 population in 2010. Less than half of all cases would have been identified based on smear microscopy results alone. Successful control efforts will require interventions targeting men, increased access to radiography and more accurate, rapid diagnostic tests.


Assuntos
Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Gâmbia/epidemiologia , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis , Prevalência , Escarro/microbiologia , Adulto Jovem
10.
Malar J ; 15(1): 515, 2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-27769292

RESUMO

BACKGROUND: Previous genome-wide analyses of single nucleotide variation in Plasmodium falciparum identified evidence of an extended haplotype region on chromosome 6 in West Africa, suggesting recent positive selection. Such a pattern is not seen in samples from East Africa or South East Asia, so it could be marking a selective process specific to West Africa. Analyses of the haplotype structure in samples taken at different times could give clues to possible causes of selection. METHODS: This study investigates chromosome 6 extended haplotypes in The Gambia by analysing alleles at multiple microsatellite loci using genome sequence data previously obtained from clinical isolates collected in 2008, followed by genotyping of 13 loci in 439 isolates from 1984, 1991, 2008 and 2014. Temporal changes in haplotype structure and frequencies were determined. RESULTS: A region of high linkage disequilibrium spanning over 170 kilobases (kb) was identified with both NGS and laboratory determined microsatellite alleles. Multiple long haplotypes were found in all temporal populations from The Gambia. Two of the haplotypes were detected in samples from 1984 and 1991. The frequency of long-range haplotypes increased in 2008 and 2014 populations. There was higher Fst between older and more recent populations at loci in proximity to genes involved in drug metabolism pathways. CONCLUSIONS: The occurrence of several long haplotypes at intermediate frequencies suggests an unusual mode of selection in chromosome 6, possibly combined with recombination suppression on specific haplotypes. Such selection apparently occurred before the emergence of known anti-malarial drug resistance alleles, and could be due to effects of other drugs or unknown processes that have long been operating in this endemic region.


Assuntos
Cromossomos , Doenças Endêmicas , Haplótipos , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Gâmbia/epidemiologia , Frequência do Gene , Técnicas de Genotipagem , Humanos , Repetições de Microssatélites , Epidemiologia Molecular , Plasmodium falciparum/isolamento & purificação , Seleção Genética , Análise de Sequência de DNA , Fatores de Tempo
11.
Am J Respir Crit Care Med ; 187(4): 439-45, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23220919

RESUMO

RATIONALE: Biomarkers that can be used to evaluate new interventions against latent tuberculosis infection (LTBI) and predict reactivation TB disease are urgently required. OBJECTIVES: To evaluate ESAT-6 and CFP-10 (EC) IFN-γ ELISPOT as a biomarker for treatment efficacy in LTBI. METHODS: This was a randomized, blinded, and placebo-controlled trial of INH in EC ELISPOT and Mantoux test positive participants. MEASUREMENTS AND MAIN RESULTS: Participants received a 6-month course of 900 mg INH twice weekly or a matching placebo. INH acetylator genotypes were determined and urine tested for INH metabolites to confirm adherence. The proportion of positive responders for CFP-10 and ESAT-6 between treatment arms was compared using mixed effects logistic regression models. A Tweedie (compound Poisson) model was fitted to allow for zero inflation and overdispersion of quantitative response. The proportions of EC ELISPOT-positive subjects reduced over time (P < 0.001) but did not differ by study arm (P = 0.36). Median spot-forming units for ESAT-6 and CFP-10 also declined significantly with time (P < 0.001) but did not differ by study arm (P = 0.74 and 0.71, respectively). There was no evidence of an interaction between acetylator status and INH treatment with respect to ELISPOT results over time. CONCLUSIONS: In contacts with LTBI, INH therapy plays no role in observed decreases in Mycobacterium tuberculosis antigen-specific T-cell responses over time. IFN-γ ELISPOT is probably not a useful biomarker of treatment efficacy in LTBI. Clinical trial registered with www.clinicaltrials.gov (NCT 00130325).


Assuntos
Antituberculosos/uso terapêutico , ELISPOT/métodos , Interferon gama/sangue , Isoniazida/uso terapêutico , Tuberculose Latente/sangue , Tuberculose Latente/tratamento farmacológico , Adulto , Biomarcadores/sangue , Método Duplo-Cego , ELISPOT/normas , Feminino , Gâmbia , Humanos , Interferon gama/efeitos dos fármacos , Masculino , Mycobacterium tuberculosis/efeitos dos fármacos , Resultado do Tratamento , Adulto Jovem
12.
Lancet Infect Dis ; 24(4): 417-426, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38237616

RESUMO

BACKGROUND: Novel oral polio vaccine type 2 (nOPV2) has been used to interrupt circulating vaccine-derived poliovirus type 2 outbreaks following its WHO emergency use listing. This study reports data on the safety and immunogenicity of nOPV2 over two rounds of a campaign in The Gambia. METHODS: This observational cohort study collected baseline symptoms (vomiting, diarrhoea, irritability, reduced feeding, and reduced activity) and axillary temperature from children aged 6 weeks to 59 months in The Gambia before a series of two rounds of a nOPV2 campaign that took place on Nov 20-26, 2021, and March 19-22, 2022. Serum and stool samples were collected from a subset of the participants. The same symptoms were re-assessed during the week following each dose of nOPV2. Stool samples were collected on days 7 and 28, and serum was collected on day 28 following each dose. Adverse events, including adverse events of special interest, were documented for 28 days after each campaign round. Serum neutralising antibodies were measured by microneutralisation assay, and stool poliovirus excretion was measured by real-time RT-PCR. FINDINGS: Of the 5635 children eligible for the study, 5504 (97·7%) received at least one dose of nOPV2. There was no increase in axillary temperature or in any of the baseline symptoms following either rounds of the campaigns. There were no adverse events of special interest and no other safety signals of concern. Poliovirus type 2 seroconversion rates were 70% (95% CI 62 to 78; 87 of 124 children) following one dose of nOPV2 and 91% (85 to 95; 113 of 124 children) following two doses. Poliovirus excretion on day 7 was lower after the second round (162 of 459 samples; 35·3%, 95% CI 31·1 to 39·8) than after the first round (292 of 658 samples; 44·4%, 40·6 to 48·2) of the campaign (difference -9·1%; 95% CI -14·8 to -3·3), showing the induction of mucosal immunity. INTERPRETATION: In a campaign in west Africa, nOPV2 was well tolerated and safe. High rates of seroconversion and evidence of mucosal immunity support the licensure and WHO prequalification of this vaccine. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Poliomielite , Poliovirus , Humanos , Anticorpos Antivirais , Gâmbia/epidemiologia , Esquemas de Imunização , Imunogenicidade da Vacina , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado , Vacina Antipólio Oral , Lactente , Pré-Escolar
13.
BMC Genomics ; 14: 23, 2013 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-23324451

RESUMO

BACKGROUND: Apoptosis is a critical process in endothelial cell (EC) biology and pathology, which has been extensively studied at protein level. Numerous gene expression studies of EC apoptosis have also been performed, however few attempts have been made to use gene expression data to identify the molecular relationships and master regulators that underlie EC apoptosis. Therefore, we sought to understand these relationships by generating a Bayesian gene regulatory network (GRN) model. RESULTS: ECs were induced to undergo apoptosis using serum withdrawal and followed over a time course in triplicate, using microarrays. When generating the GRN, this EC time course data was supplemented by a library of microarray data from EC treated with siRNAs targeting over 350 signalling molecules.The GRN model proposed Vasohibin-1 (VASH1) as one of the candidate master-regulators of EC apoptosis with numerous downstream mRNAs. To evaluate the role played by VASH1 in EC, we used siRNA to reduce the expression of VASH1. Of 10 mRNAs downstream of VASH1 in the GRN that were examined, 7 were significantly up- or down-regulated in the direction predicted by the GRN.Further supporting an important biological role of VASH1 in EC, targeted reduction of VASH1 mRNA abundance conferred resistance to serum withdrawal-induced EC death. CONCLUSION: We have utilised Bayesian GRN modelling to identify a novel candidate master regulator of EC apoptosis. This study demonstrates how GRN technology can complement traditional methods to hypothesise the regulatory relationships that underlie important biological processes.


Assuntos
Apoptose/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Endoteliais/citologia , Redes Reguladoras de Genes/genética , Teorema de Bayes , Proteínas de Ciclo Celular/deficiência , Biologia Computacional , Células Endoteliais/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Modelos Genéticos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética
14.
BMC Public Health ; 13 Suppl 2: S3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23902668

RESUMO

BACKGROUND: Global health implementing organizations benefit most from health impact estimation models that isolate the individual effects of distributed products and services - a feature not typically found in intervention impact models, but which allow comparisons across interventions and intervention settings. Population Services International (PSI), a social marketing organization, has developed a set of impact models covering seven health program areas, which translate product/service distribution data into impact estimates. Each model's primary output is the number of disability-adjusted life-years (DALYs) averted by an intervention within a specific country and population context. This paper aims to describe the structure and inputs for two types of DALYs averted models, considering the benefits and limitations of this methodology. METHODS: PSI employs two modeling approaches for estimating health impact: a macro approach for most interventions and a micro approach for HIV, tuberculosis (TB), and behavior change communication (BCC) interventions. Within each intervention country context, the macro approach determines the coverage that one product/service unit provides a population in person-years, whereas the micro approach estimates an individual's risk of infection with and without the product/service unit. The models use these estimations to generate per unit DALYs averted coefficients for each intervention. When multiplied by program output data, these coefficients predict the total number of DALYs averted by an intervention in a country. RESULTS: Model outputs are presented by country for two examples: Water Chlorination DALYs Averted Model, a macro model, and the HIV Condom DALYs Averted Model for heterosexual transmission, a micro model. Health impact estimates measured in DALYs averted for PSI interventions on a global level are also presented. CONCLUSIONS: The DALYs averted models offer implementing organizations practical measurement solutions for understanding an intervention's contribution to improving health. These models calculate health impact estimates that reflect the scale and diversity of program operations and intervention settings, and that enable comparisons across health areas and countries. Challenges remain in accounting for intervention synergies, attributing impact to a single organization, and sourcing and updating model inputs. Nevertheless, these models demonstrate how DALYs averted can be viably used by the global health community as a metric for predicting intervention impact using standard program output data.


Assuntos
Saúde Global , Agências Internacionais/organização & administração , Modelos Estatísticos , Avaliação de Programas e Projetos de Saúde/métodos , Pessoas com Deficiência/estatística & dados numéricos , Humanos , Anos de Vida Ajustados por Qualidade de Vida
15.
Int J Infect Dis ; 128: 61-68, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36566776

RESUMO

OBJECTIVES: Estimates for COVID-19-related excess mortality for African populations using local data are needed to design and implement effective control policies. METHODS: We applied time-series analysis using data from three health and demographic surveillance systems in The Gambia (Basse, Farafenni, and Keneba) to examine pandemic-related excess mortality during 2020, when the first SARS-CoV-2 wave was observed, compared to the pre-pandemic period (2016-2019). RESULTS: Across the three sites, average mortality during the pre-pandemic period and the total deaths during 2020 were 1512 and 1634, respectively (Basse: 1099 vs 1179, Farafenni: 316 vs 351, Keneba: 98 vs 104). The overall annual crude mortality rates per 100,000 (95% CI) were 589 (559, 619) and 599 (571, 629) for the pre-pandemic and 2020 periods, respectively. The adjusted excess mortality rate was 8.8 (-34.3, 67.6) per 100,000 person-month with the adjusted rate ratio (aRR) = 1.01 (0.94,1.11). The age-stratified analysis showed excess mortality in Basse for infants (aRR = 1.22 [1.04, 1.46]) and in Farafenni for the 65+ years age group (aRR = 1.19 [1, 1.44]). CONCLUSION: We did not find significant excess overall mortality in 2020 in The Gambia. However, some age groups may have been at risk of excess death. Public health response in countries with weak health systems needs to consider vulnerable age groups and the potential for collateral damage.


Assuntos
COVID-19 , Lactente , Humanos , Idoso , COVID-19/epidemiologia , Pandemias , Gâmbia/epidemiologia , SARS-CoV-2 , Demografia , Mortalidade
16.
Campbell Syst Rev ; 18(4): e1287, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36908831

RESUMO

Background: In the Asia-Pacific region, around one-third of the children who are out-of-school have a disability and given that teacher readiness and capability are key contributors for inclusive education, it is high time for a mapping of disability inclusive teacher professional development (TPD) interventions in this region. Objectives: The key objective of this evidence and gap map (EGM) is to locate evidence on interventions for in-service TPD focussing on education for the inclusion of students with a disability in low- and middle-income countries (LMICs) in the Asia-Pacific region. Search Methods: A broad range of bibliographic databases and repositories were searched electronically to identify the evidence published between January 2000 and December 2021. Key search platforms included the British Education Index (BEI), Education Research Complete (ERC), Education Resources Information Center (ERIC), SCOPUS, 3ie Development Evidence Portal (Evidence Hub) and the Campbell Collaborations Systematic Reviews and EGMs portal (Better evidence for a better world). In addition, potential program evaluations/impact reports, reviews, case studies, and program descriptions/summaries were sought through 'snowballing' based on searching bibliographies and reference lists of papers located during the search process, as well as specific searches of relevant grey literature. Selection Criteria: To be eligible for inclusion, studies had to contain sufficient details about TPD interventions that support early childhood educators and kindergarten to Year 12 teachers to understand the needs of students with disabilities and aid them to create inclusive mainstream classrooms and/or provide improved support for students with disabilities in special education settings. Data Collection and Analysis: A total of 820 records were entered into the MS Excel file in which the entire data extraction process was managed. All records were screened against the predefined inclusion and exclusion criteria. Data were extracted independently by two reviewers and any differences were resolved through consultations. All included studies and their characteristics were extracted from the MS Excel file and uploaded to the ACER server in.csv file format. The interactive, online EGM is available here: https://datavis.acer.org/gem/disability-inclusion-TPD/. Main Results: Fifty studies from 16 countries out of the 41 LMICs in the Asia-Pacific region were identified, whereby Thailand had the largest number of studies with evidence (7) followed by China, Vietnam, and India (5 each). Two main gaps in research about professional learning were identified. First, only three studies reported interventions aimed at supporting mental health among students with a disability. Second, no studies were found that reported on how teachers could support positive student behaviour. These gaps are important because research has persistently suggested that experiencing disability is an important risk factor for young people developing mental health conditions. Authors' Conclusions: This report illustrates the critical value of evaluating and publishing evidence from disability inclusive TPD interventions in LMICs, including any that are ongoing, or are components of highly resource intensive large-scale education sector programs.

17.
Lancet Glob Health ; 10(2): e257-e268, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34951974

RESUMO

BACKGROUND: A rapid increase in circulating vaccine-derived poliovirus type 2 outbreaks, and the need to reserve inactivated poliovirus vaccine (IPV) for routine immunisation, has increased the value of fractional dose IPV (fIPV) as a measure to prevent acute flaccid paralysis. However, the intradermal route of administration has been viewed as prohibitive to outbreak response campaigns. We aimed to establish the immunogenicity and safety of administering intradermal fIPV with a disposable syringe jet injector (DSJI) or an intradermal adaptor (IDA) compared with standard administration with a BCG needle and syringe (N&S). METHODS: This pragmatic, non-inferiority trial was undertaken in a campaign setting in communities in The Gambia. Children aged 4-59 months without contraindication to vaccination were eligible. Children were not individually randomly assigned; instead, the vaccination teams were randomly assigned (1:1:1) to one of three administration methods. Parents and the field team were not masked, but laboratory personnel were masked. Baseline demographic and anthropometric data were collected from the participants. Public health officers experienced at intradermal immunisation, and nurses without experience, had 2 h of training on each of the administration methods before the campaign. Participants were vaccinated using the administration method in use by the vaccination team in their community. Poliovirus serum neutralising antibodies (SNA) were measured in children aged 24-59 months before and 4 weeks after vaccination. Adverse events and data on injection quality were collected from all participants. The primary outcome was the type 2 immune response rate (seroconversion in seronegative [SNA titre <8] children plus a 4-fold titre rise in seropositive children). Adjusted differences in the immune response between the DSJI or IDA group versus the N&S group were calculated with 97·5% CIs. A margin of -10% was used to define the non-inferiority of DSJI or IDA compared to N&S. Immunogenicity analysis was done per protocol. The trial is registered with ClinicalTrials.govNCT02967783 and has been completed. FINDINGS: Between Oct 28 and Dec 29, 2016, 3189 children aged 4-59 months were recruited, of whom 3170 were eligible. Over 3 days, 2720 children were vaccinated (N&S, 917; IDA, 874; and DSJI, 929). Among 992 children aged 25-59 months with a baseline SNA available, 90·1% (95% CI 86·1-92·9; 281/312) of those vaccinated using the DSJI had an immune response to type 2 compared with 93·8% (90·6-95·8; 331/353) of those vaccinated with N&S and 96·6% (94·0-98·0; 316/327) of those vaccinated with IDA. All (53/53) type 2 seronegative children seroconverted. For polio type 2, non-inferiority was shown for both the IDA (adjusted difference 0·7% [97·5% CI -3·3 to 4·7], unadjusted difference 2·9% [-0·9 to 6·8]) and DSJI (adjusted difference -3·3% [-8·3 to 1·5], unadjusted difference -3·7% [-8·7 to 1·1]) compared with N&S. Non-inferiority was shown for type 1 and 3 for the IDA and DSJI. Neither injection quality nor the training and experience of the vaccinators had an effect on immune response. No safety concerns were reported. INTERPRETATION: In a campaign, intradermal fIPV is safe and generates consistent immune responses that are not dependent on vaccinator experience or injection quality when administered using an N&S, DSJI, or IDA. Countries facing vaccine-derived poliovirus type 2 outbreaks should consider fIPV campaigns to boost population immunity and prevent cases of acute flaccid paralysis. FUNDING: World Health Organization and the Medical Research Council.


Assuntos
Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/administração & dosagem , Vacina Antipólio de Vírus Inativado/imunologia , Pré-Escolar , Relação Dose-Resposta a Droga , Estudos de Equivalência como Asunto , Feminino , Gâmbia , Humanos , Lactente , Injeções Intradérmicas , Masculino
18.
Trials ; 23(1): 775, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104719

RESUMO

BACKGROUND: New strategies to increase measles and rubella vaccine coverage, particularly in low- and middle-income countries, are needed if elimination goals are to be achieved. With this regard, measles and rubella vaccine microneedle patches (MRV-MNP), in which the vaccine is embedded in dissolving microneedles, offer several potential advantages over subcutaneous delivery. These include ease of administration, increased thermostability, an absence of sharps waste, reduced overall costs and pain-free administration. This trial will provide the first clinical trial data on MRV-MNP use and the first clinical vaccine trial of MNP technology in children and infants. METHODS: This is a phase 1/2, randomized, active-controlled, double-blind, double-dummy, age de-escalation trial. Based on the defined eligibility criteria for the trial, including screening laboratory investigations, 45 adults [18-40 years] followed by 120 toddlers [15-18 months] and 120 infants [9-10 months] will be enrolled in series. To allow double-blinding, participants will receive either the MRV-MNP and a placebo (0.9% sodium chloride) subcutaneous (SC) injection or a placebo MNP and the MRV by SC injection (MRV-SC). Local and systemic adverse event data will be collected for 14 days following study product administration. Safety laboratories will be repeated on day 7 and, in the adult cohort alone, on day 14. Unsolicited adverse events including serious adverse events will be collected until the final study visit for each participant on day 180. Measles and rubella serum neutralizing antibodies will be measured at baseline, on day 42 and on day 180. Cohort progression will be dependent on review of the unblinded safety data by an independent data monitoring committee. DISCUSSION: This trial will provide the first clinical data on the use of a MNP to deliver the MRV and the first data on the use of MNPs in a paediatric population. It will guide future product development decisions for what may be a key technology for future measles and rubella elimination. TRIAL REGISTRATION: Pan-African Clinical Trials Registry 202008836432905 . CLINICALTRIALS: gov NCT04394689.


Assuntos
Vacina contra Sarampo , Sarampo , Vacina contra Rubéola , Rubéola (Sarampo Alemão) , Adolescente , Adulto , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Método Duplo-Cego , Gâmbia , Humanos , Lactente , Sarampo/prevenção & controle , Vacina contra Sarampo/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Rubéola (Sarampo Alemão)/prevenção & controle , Vacina contra Rubéola/efeitos adversos , Adulto Jovem
20.
PLoS Pathog ; 5(4): e1000364, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19343213

RESUMO

Failure to establish an appropriate balance between pro- and anti-inflammatory immune responses is believed to contribute to pathogenesis of severe malaria. To determine whether this balance is maintained by classical regulatory T cells (CD4(+) FOXP3(+) CD127(-/low); Tregs) we compared cellular responses between Gambian children (n = 124) with severe Plasmodium falciparum malaria or uncomplicated malaria infections. Although no significant differences in Treg numbers or function were observed between the groups, Treg activity during acute disease was inversely correlated with malaria-specific memory responses detectable 28 days later. Thus, while Tregs may not regulate acute malarial inflammation, they may limit memory responses to levels that subsequently facilitate parasite clearance without causing immunopathology. Importantly, we identified a population of FOXP3(-), CD45RO(+) CD4(+) T cells which coproduce IL-10 and IFN-gamma. These cells are more prevalent in children with uncomplicated malaria than in those with severe disease, suggesting that they may be the regulators of acute malarial inflammation.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Fatores de Transcrição Forkhead/metabolismo , Imunidade Celular , Malária Falciparum/imunologia , Doença Aguda , Linfócitos T CD4-Positivos/metabolismo , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Feminino , Fatores de Transcrição Forkhead/genética , Gâmbia , Humanos , Memória Imunológica , Inflamação , Interferon gama/metabolismo , Interleucina-10/metabolismo , Antígenos Comuns de Leucócito/metabolismo , Modelos Lineares , Masculino , Estatísticas não Paramétricas , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Células Th1/metabolismo
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