Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 178
Filter
2.
Vaccine ; 42(9): 2290-2298, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38431444

ABSTRACT

BACKGROUND: World Health Organization human papillomavirus (HPV) vaccination recommendations include a single- or two-dose schedule in individuals 9-20 years old and advice for generating data on single-dose efficacy or immunobridging. The ongoing Phase 3 trial of Innovax's bivalent (types 16 and 18) HPV vaccine (Cecolin®) assesses in low- and middle-income countries alternative dosing schedules and generates data following one dose in girls 9-14 years old. Interim data for the 6-month dosing groups are presented. METHODS: In Bangladesh and Ghana, 1,025 girls were randomized to receive either two doses of Cecolin at 6-, 12-, or 24-month intervals; one dose of Gardasil® followed by one dose of Cecolin at month 24; or two doses of Gardasil 6 months apart (referent). Serology was measured by enzyme-linked immunosorbent assay (ELISA) and, in a subset, by neutralization assays. Primary objectives include immunological non-inferiority of the Cecolin schedules to referent one month after the second dose. Safety endpoints include reactogenicity and unsolicited adverse events for 7 and 30 days post-vaccination, respectively, as well as serious adverse events throughout the study. RESULTS: Interim analyses included data from the two groups on a 0, 6-month schedule with 205 participants per group. One month after Dose 2, 100% of participants were seropositive by ELISA and had seroconverted for both antigens. Non-inferiority of Cecolin to Gardasil was demonstrated. Six months following one dose, over 96% of participants were seropositive by ELISA for both HPV antigens, with a trend for higher geometric mean concentration following Cecolin administration. Reactogenicity and safety were comparable between both vaccines. CONCLUSIONS: Cecolin in a 0, 6-month schedule elicits robust immunogenicity. Non-inferiority to Gardasil was demonstrated one month after a 0, 6-month schedule. Immunogenicity following one dose was comparable to Gardasil up to six months. Both vaccines were safe and well tolerated (ClinicalTrials.gov No. 04508309).


Subject(s)
Papillomavirus Infections , Papillomavirus Vaccines , Female , Humans , Child , Adolescent , Young Adult , Adult , Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18/adverse effects , Papillomavirus Infections/prevention & control , Antibodies, Viral , Vaccination , Immunogenicity, Vaccine
3.
J Infect Dis ; 228(2): 212-223, 2023 07 14.
Article in English | MEDLINE | ID: mdl-37042518

ABSTRACT

Transmission-blocking interventions can play an important role in combating malaria worldwide. Recently, a highly potent Plasmodium falciparum transmission-blocking monoclonal antibody (TB31F) was demonstrated to be safe and efficacious in malaria-naive volunteers. Here we predict the potential public health impact of large-scale implementation of TB31F alongside existing interventions. We developed a pharmaco-epidemiological model, tailored to 2 settings of differing transmission intensity with already established insecticide-treated nets and seasonal malaria chemoprevention interventions. Community-wide annual administration (at 80% coverage) of TB31F over a 3-year period was predicted to reduce clinical incidence by 54% (381 cases averted per 1000 people per year) in a high-transmission seasonal setting, and 74% (157 cases averted per 1000 people per year) in a low-transmission seasonal setting. Targeting school-aged children gave the largest reduction in terms of cases averted per dose. An annual administration of the transmission-blocking monoclonal antibody TB31F may be an effective intervention against malaria in seasonal malaria settings.


Subject(s)
Malaria, Falciparum , Malaria , Child , Humans , Plasmodium falciparum , Malaria, Falciparum/epidemiology , Malaria, Falciparum/prevention & control , Malaria, Falciparum/drug therapy , Seasons , Malaria/prevention & control , Antibodies, Monoclonal/therapeutic use
4.
PLoS Med ; 19(9): e1004084, 2022 09.
Article in English | MEDLINE | ID: mdl-36054101

ABSTRACT

BACKGROUND: Malaria is among the top causes of death in adolescent girls (10 to 19 years) globally. Adolescent motherhood is associated with increased risk of adverse maternal and neonatal outcomes. The interaction of malaria, adolescence, and pregnancy is especially relevant in malaria endemic areas, where rates of adolescent pregnancy are high. However, data on burden of malaria among adolescent girls are limited. This study aimed at investigating whether adolescent girls were at a greater risk of experiencing malaria-related outcomes in pregnancy-parasitaemia and clinical disease-than adult women. METHODS AND FINDINGS: An individual secondary participant-level meta-analysis was conducted using data from 5,804 pregnant women participating in 2 malaria prevention clinical trials in Benin, Gabon, Kenya, Mozambique, and Tanzania between 2009 and 2014. Of the sample, 1,201 participants were adolescent girls with a mean age of 17.5 years (standard deviation (SD) 1.3) and 886 (73.8%) of them primigravidae. Among the 4,603 adult women with mean age of 27.0 years (SD 5.4), 595 (12.9%) were primigravidae. Mean gestational age at enrolment was 20.2 weeks (SD 5.2) and 1,069 (18.4%) participants were HIV-infected. Women were followed monthly until the postpartum visit (1 month to 6 weeks after delivery). This study considered outcomes including clinical episodes during pregnancy, peripheral parasitaemia at delivery, and placental malaria. A 2-stage meta-analysis approach was followed by pooling single multivariable regression results into standard DerSimonian-Laird random-effects models. Adolescent girls were more likely than adult women to present with clinical malaria during pregnancy (incidence risk ratio (IRR) 1.70, 95% confidence interval (CI) 1.20; 2.39, p-value = 0.003, I2 = 0.0%, N = 4,092), peripheral parasitaemia at delivery (odds ratio (OR) 2.28, 95% CI 1.46; 3.55, p-value < 0.001, I2 = 0.0%, N = 3,977), and placental infection (OR 1.97, 95% CI 1.31; 2.98, p-value = 0.001, I2 = 1.4%, N = 4,797). Similar associations were observed among the subgroup of HIV-uninfected participants: IRR 1.72 (95% CI 1.22; 2.45, p-value = 0.002, I2 = 0.0%, N = 3,531) for clinical malaria episodes, OR 2.39 (95% CI 1.49; 3.86, p-value < 0.001, I2 = 0.0%, N = 3,053) for peripheral parasitaemia, and OR 1.88 (95% CI 1.06 to 3.33, p-value = 0.03, I2 = 34.9%, N = 3,847) for placental malaria. Among HIV-infected subgroups statistically significant associations were not observed. Similar associations were found in the subgroup analysis by gravidity. The small sample size and outcome prevalence in specific countries limited the inclusion of some countries in the meta-analysis. Furthermore, peripheral parasitaemia and placental malaria presented a considerable level of missing data-12.6% and 18.2% of participants had missing data on those outcomes, respectively. Given the original scope of the clinical trials, asymptomatic malaria infection was only assessed at the end of pregnancy through peripheral and placental parasitaemia. CONCLUSIONS: In this study, we observed that adolescent girls in sub-Saharan Africa (SSA) are more prone to experience clinical malaria episodes during pregnancy and have peripheral malaria and placental infection at delivery than adult women. Moreover, to the best of our knowledge, for the first time this study disaggregates figures and stratifies analyses by HIV infection. Similar associations were found for both HIV-infected and uninfected women, although those for HIV-infected participants were not statistically significant. Our finding suggests that adolescent girls may benefit from targeted malaria prevention strategies even before they become pregnant.


Subject(s)
Antimalarials , HIV Infections , Malaria , Pregnancy Complications, Infectious , Pregnancy Complications, Parasitic , Adolescent , Adult , Antimalarials/therapeutic use , Female , HIV Infections/complications , HIV Infections/epidemiology , Humans , Infant, Newborn , Kenya , Malaria/prevention & control , Parasitemia/drug therapy , Parasitemia/epidemiology , Placenta , Pregnancy , Pregnancy Complications, Infectious/drug therapy , Pregnancy Complications, Parasitic/prevention & control
5.
PloS med ; 19(9): [1-20], Set. 02, 2022. Tab, Grf
Article in English | AIM (Africa), RSDM | ID: biblio-1527005

ABSTRACT

Malaria is among the top causes of death in adolescent girls (10 to 19 years) globally. Adolescent motherhood is associated with increased risk of adverse maternal and neonatal outcomes. The interaction of malaria, adolescence, and pregnancy is especially relevant in malaria endemic areas, where rates of adolescent pregnancy are high. However, data on burden of malaria among adolescent girls are limited. This study aimed at investigating whether adolescent girls were at a greater risk of experiencing malaria-related outcomes in pregnancy-parasitaemia and clinical disease-than adult women. An individual secondary participant-level meta-analysis was conducted using data from 5,804 pregnant women participating in 2 malaria prevention clinical trials in Benin, Gabon, Kenya, Mozambique, and Tanzania between 2009 and 2014. Of the sample, 1,201 participants were adolescent girls with a mean age of 17.5 years (standard deviation (SD) 1.3) and 886 (73.8%) of them primigravidae. Among the 4,603 adult women with mean age of 27.0 years (SD 5.4), 595 (12.9%) were primigravidae. Mean gestational age at enrolment was 20.2 weeks (SD 5.2) and 1,069 (18.4%) participants were HIV-infected. Women were followed monthly until the postpartum visit (1 month to 6 weeks after delivery). This study considered outcomes including clinical episodes during pregnancy, peripheral parasitaemia at delivery, and placental malaria. A 2-stage meta-analysis approach was followed by pooling single multivariable regression results into standard DerSimonian-Laird random-effects models. Adolescent girls were more likely than adult women to present with clinical malaria during pregnancy (incidence risk ratio (IRR) 1.70, 95% confidence interval (CI) 1.20; 2.39, p-value = 0.003, I2 = 0.0%, N = 4,092), peripheral parasitaemia at delivery (odds ratio (OR) 2.28, 95% CI 1.46; 3.55, p-value < 0.001, I2 = 0.0%, N = 3,977), and placental infection (OR 1.97, 95% CI 1.31; 2.98, p-value = 0.001, I2 = 1.4%, N = 4,797). Similar associations were observed among the subgroup of HIV-uninfected participants: IRR 1.72 (95% CI 1.22; 2.45, p-value = 0.002, I2 = 0.0%, N = 3,531) for clinical malaria episodes, OR 2.39 (95% CI 1.49; 3.86, p-value < 0.001, I2 = 0.0%, N = 3,053) for peripheral parasitaemia, and OR 1.88 (95% CI 1.06 to 3.33, p-value = 0.03, I2 = 34.9%, N = 3,847) for placental malaria. Among HIV-infected subgroups statistically significant associations were not observed. Similar associations were found in the subgroup analysis by gravidity. The small sample size and outcome prevalence in specific countries limited the inclusion of some countries in the meta-analysis. Furthermore, peripheral parasitaemia and placental malaria presented a considerable level of missing data-12.6% and 18.2% of participants had missing data on those outcomes, respectively. Given the original scope of the clinical trials, asymptomatic malaria infection was only assessed at the end of pregnancy through peripheral and placental parasitaemia.


Subject(s)
Humans , Female , Pregnancy , Adolescent , Adult , Malaria/epidemiology , Pregnancy , Mozambique/epidemiology
6.
Lancet Infect Dis ; 22(11): 1596-1605, 2022 11.
Article in English | MEDLINE | ID: mdl-35963275

ABSTRACT

BACKGROUND: Malaria elimination requires interruption of the highly efficient transmission of Plasmodium parasites by mosquitoes. TB31F is a humanised monoclonal antibody that binds the gamete surface protein Pfs48/45 and inhibits fertilisation, thereby preventing further parasite development in the mosquito midgut and onward transmission. We aimed to evaluate the safety and efficacy of TB31F in malaria-naive participants. METHODS: In this open-label, first-in-human, dose-escalation, phase 1 clinical trial, healthy, malaria-naive, adult participants were administered a single intravenous dose of 0·1, 1, 3, or 10 mg/kg TB31F or a subcutaneous dose of 100 mg TB31F, and monitored until day 84 after administration at a single centre in the Netherlands. The primary outcome was the frequency and magnitude of adverse events. Additionally, TB31F serum concentrations were measured by ELISA. Transmission-reducing activity (TRA) of participant sera was assessed by standard membrane feeding assays with Anopheles stephensi mosquitoes and cultured Plasmodium falciparum gametocytes. The trial is registered with Clinicaltrials.gov, NCT04238689. FINDINGS: Between Feb 17 and Dec 10, 2020, 25 participants were enrolled and sequentially assigned to each dose (n=5 per group). No serious or severe adverse events occurred. In total, 33 grade 1 and six grade 2 related adverse events occurred in 20 (80%) of 25 participants across all groups. Serum of all participants administered 1 mg/kg, 3 mg/kg, or 10 mg/kg TB31F intravenously had more than 80% TRA for 28 days or more, 56 days or more, and 84 days or more, respectively. The TB31F serum concentration reaching 80% TRA was 2·1 µg/mL (95% CI 1·9-2·3). Extrapolating the duration of TRA from antibody kinetics suggests more than 80% TRA is maintained for 160 days (95% CI 136-193) following a single intravenous 10 mg/kg dose. INTERPRETATION: TB31F is a well tolerated and highly potent monoclonal antibody capable of completely blocking transmission of P falciparum parasites from humans to mosquitoes. In areas of seasonal transmission, a single dose might cover an entire malaria season. FUNDING: PATH's Malaria Vaccine Initiative.


Subject(s)
Antimalarials , Malaria Vaccines , Malaria, Falciparum , Adult , Animals , Humans , Plasmodium falciparum , Antibodies, Monoclonal/therapeutic use , Malaria, Falciparum/drug therapy , Malaria, Falciparum/prevention & control , Malaria, Falciparum/parasitology
7.
Lancet Glob Health ; 10(6): e873-e881, 2022 06.
Article in English | MEDLINE | ID: mdl-35561722

ABSTRACT

BACKGROUND: Most malaria burden estimates rely on modelling infection prevalence to case incidence data, with insufficient attention having been paid to the changing clinical presentation of severe disease and its relationship with changing transmission intensity. We present 20 years of longitudinal surveillance data to contribute to the understanding of the relationship between malaria transmission and the burden and clinical presentation of severe malaria and to inform policy. METHODS: This retrospective analysis of clinical surveillance hospital data included all children younger than 15 years admitted with malaria to Manhiça District Hospital (MDH), Mozambique, from July 1, 1997, to June 30, 2017. Case fatality ratios (CFRs) were calculated as the number of patients who died having a specific diagnosis or syndrome divided by the total number of patients with known outcome admitted with that diagnosis or syndrome. FINDINGS: Over the study period, 32 138 children were admitted to MDH with a malaria diagnosis. Malaria accounted for a large proportion of admissions, ranging from 4083 (76·9%) of 5307 admissions in 2000-01 to 706 (27·5%) of 2568 admissions in 2010-11. Since 2000-02, the absolute and relative number of malaria admissions and deaths presented a decreasing trend. The age pattern of patients with malaria shifted to older ages with a median age of 1·7 years (IQR 0·9-3·0) in 1997-2006 and 2·6 years (IQR 1·3-4·4) in 2006-17, although most malaria deaths (60-88% in 2009-17) still occurred in children younger than 5 years. The clinical presentation of severe malaria changed, with an increase in cerebral malaria and a decrease in severe anaemia and respiratory distress, leading to similar yearly cases for the three syndromes. CFRs for severe malaria fluctuated between 1·1% (2 of 186 in 2014-15) and 7·2% (11 of 152 in 2010-11), varying by severe malaria syndrome (3·3% [70 of 2105] for severe anaemia, 5·1% [191 of 3777] for respiratory distress, and 14·8% [72 of 487] for cerebral malaria). Overall malaria CFRs (1·8% [543 of 30 163]) did not vary by age group. INTERPRETATION: Despite the unprecedented scale up of malaria control tools, malaria still represented around 30-40% of paediatric hospital admissions in 2006-17. The age shift towards older children was not accompanied by an increase in severe malaria or deaths; however, control programmes should consider adapting their high-risk target groups to include older children. Malaria remains a leading cause of disease and health-care system use and the massive unfinished malaria control agenda warrants intensified efforts. FUNDING: Spanish Agency for International Cooperation and Development.


Subject(s)
Anemia , Malaria, Cerebral , Respiratory Distress Syndrome , Adolescent , Child , Child, Preschool , Hospitals, District , Humans , Infant , Mozambique/epidemiology , Retrospective Studies
8.
Elife ; 112022 01 21.
Article in English | MEDLINE | ID: mdl-35060479

ABSTRACT

Background: In a phase 3 trial in African infants and children, the RTS,S/AS01 vaccine (GSK) showed moderate efficacy against clinical malaria. We sought to further understand RTS,S/AS01-induced immune responses associated with vaccine protection. Methods: Applying the blood transcriptional module (BTM) framework, we characterized the transcriptomic response to RTS,S/AS01 vaccination in antigen-stimulated (and vehicle control) peripheral blood mononuclear cells sampled from a subset of trial participants at baseline and month 3 (1-month post-third dose). Using a matched case-control study design, we evaluated which of these 'RTS,S/AS01 signature BTMs' associated with malaria case status in RTS,S/AS01 vaccinees. Antigen-specific T-cell responses were analyzed by flow cytometry. We also performed a cross-study correlates analysis where we assessed the generalizability of our findings across three controlled human malaria infection studies of healthy, malaria-naive adult RTS,S/AS01 recipients. Results: RTS,S/AS01 vaccination was associated with downregulation of B-cell and monocyte-related BTMs and upregulation of T-cell-related BTMs, as well as higher month 3 (vs. baseline) circumsporozoite protein-specific CD4+ T-cell responses. There were few RTS,S/AS01-associated BTMs whose month 3 levels correlated with malaria risk. In contrast, baseline levels of BTMs associated with dendritic cells and with monocytes (among others) correlated with malaria risk. The baseline dendritic cell- and monocyte-related BTM correlations with malaria risk appeared to generalize to healthy, malaria-naive adults. Conclusions: A prevaccination transcriptomic signature associates with malaria in RTS,S/AS01-vaccinated African children, and elements of this signature may be broadly generalizable. The consistent presence of monocyte-related modules suggests that certain monocyte subsets may inhibit protective RTS,S/AS01-induced responses. Funding: Funding was obtained from the NIH-NIAID (R01AI095789), NIH-NIAID (U19AI128914), PATH Malaria Vaccine Initiative (MVI), and Ministerio de Economía y Competitividad (Instituto de Salud Carlos III, PI11/00423 and PI14/01422). The RNA-seq project has been funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under grant number U19AI110818 to the Broad Institute. This study was also supported by the Vaccine Statistical Support (Bill and Melinda Gates Foundation award INV-008576/OPP1154739 to R.G.). C.D. was the recipient of a Ramon y Cajal Contract from the Ministerio de Economía y Competitividad (RYC-2008-02631). G.M. was the recipient of a Sara Borrell-ISCIII fellowship (CD010/00156) and work was performed with the support of Department of Health, Catalan Government grant (SLT006/17/00109). This research is part of the ISGlobal's Program on the Molecular Mechanisms of Malaria which is partially supported by the Fundación Ramón Areces and we acknowledge support from the Spanish Ministry of Science and Innovation through the 'Centro de Excelencia Severo Ochoa 2019-2023' Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program.


Subject(s)
Leukocytes, Mononuclear , Malaria Vaccines/immunology , Malaria, Falciparum , Transcriptome , Vaccines, Synthetic/immunology , Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Case-Control Studies , Child, Preschool , Clinical Trials, Phase III as Topic , Humans , Infant , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Malaria, Falciparum/immunology , Malaria, Falciparum/prevention & control , Mozambique , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Tanzania , Transcriptome/genetics , Transcriptome/immunology
9.
Med. vet. entomol ; 36(2): 1-13, 2022. tab, ilus, graf
Article in English | RSDM, Sec. Est. Saúde SP | ID: biblio-1525640

ABSTRACT

Background: At times, ultrasound is not readily available in low resource countries in Africa for accurate determination of gestational age, so using alternative methods is pivotal during pregnancy. These assessments are used to aid the risk analysis for an infant and management strategies for premature delivery, if necessary. Currently, date of last menstrual period, fundal height measurements, and the New Ballard Score are commonly used in resource-limited settings. However, concordance of these measures is unknown for sub-Saharan Africa. We obtained data from an open-label randomized controlled trial, to assess the concordance of these alternative assessment methods. The purpose of our study was to determine the agreement between these alternative methods when used in sub-Saharan African populations. Methods: A total of 4,390 pregnant women from Benin, Gabon, Mozambique and Tanzania were included in our analysis. The assessment methods compared were: 1) reported last menstrual period, 2) symphysis-fundal height measurement, and 3) the New Ballard Score. The Bland-Altman method and intraclass correlation coefficient (ICC) were used to test the degree of agreement. Survival range gestational age, used as an inclusion criterion for further analysis, was from 22 to 44 weeks. Findings: Plots showed a lack of agreement between methods and the 95% limits of agreement too wide to be clinically useful. ICC = 0.25 indicated poor agreement. A post-hoc analysis, restricted from 32 to 42 weeks, was done to check for better agreement in this near-term population. The plots and ICC = 0.16 still confirmed poor agreement.


Subject(s)
Humans , Female , Pregnancy , Infant, Newborn , Adolescent , Adult , Ultrasonography, Prenatal/statistics & numerical data , Gestational Age , Maternal Health , Reproducibility of Results , Fetal Development/physiology , Mozambique/epidemiology
10.
J. infect ; 82(4): 45-57, abr. 2021.
Article in English | AIM (Africa), RSDM | ID: biblio-1526514

ABSTRACT

Maternal Plasmodium falciparum-specific antibodies may contribute to protect infants against severe malaria. Our main objective was to evaluate the impact of maternal HIV infection and placental malaria on the cord blood levels and efficiency of placental transfer of IgG and IgG subclasses. Methods: In a cohort of 341 delivering HIV-negative and HIV-positive mothers from southern Mozambique, we measured total IgG and IgG subclasses in maternal and cord blood pairs by quantitative suspension array technology against eight P. falciparum antigens: Duffy-binding like domains 3-4 of VAR2CSA from the erythrocyte membrane protein 1, erythrocyte-binding antigen 140, exported protein 1 (EXP1), merozoite surface proteins 1, 2 and 5, and reticulocyte-binding-homologue-4.2 (Rh4.2). We performed univariable and multivariable regression models to assess the association of maternal HIV infection, placental malaria, maternal variables and pregnancy outcomes on cord antibody levels and antibody transplacental transfer. Results: Maternal antibody levels were the main determinants of cord antibody levels. HIV infection and placental malaria reduced the transfer and cord levels of IgG and IgG1, and this was antigen-dependent. Low birth weight was associated with an increase of IgG2 in cord against EXP1 and Rh4.2. Conclusions: We found lower maternally transferred antibodies in HIV-exposed infants and those born from mothers with placental malaria, which may underlie increased susceptibility to malaria in these children.


Subject(s)
Humans , HIV , Fetal Blood , Schools, Nursery , Immunoglobulin G , Malaria
11.
Front Immunol ; 12: 614246, 2021.
Article in English | MEDLINE | ID: mdl-33746958

ABSTRACT

Transplacental transfer of antibodies is essential for conferring protection in newborns against infectious diseases. We assessed the impact of different factors, including gestational age and maternal infections such as HIV and malaria, on the efficiency of cord blood levels and placental transfer of IgG subclasses. We measured total IgG and IgG subclasses by quantitative suspension array technology against 14 pathogens and vaccine antigens, including targets of maternal immunization, in 341 delivering HIV-uninfected and HIV-infected mother-infant pairs from southern Mozambique. We analyzed the association of maternal HIV infection, Plasmodium falciparum exposure, maternal variables and pregnancy outcomes on cord antibody levels and transplacental transfer. Our results show that maternal antibody levels were the main determinant of cord antibody levels. Univariable and multivariable analysis showed that HIV reduced the placental transfer and cord levels of IgG and IgG1 principally, but also IgG2 to half of the antigens tested. P. falciparum exposure and prematurity were negatively associated with cord antibody levels and placental transfer, but this was antigen-subclass dependent. Our findings suggest that lower maternally transferred antibodies may underlie increased susceptibility to infections of HIV-exposed infants. This could affect efficacy of maternal vaccination, especially in sub-Saharan Africa, where there is a high prevalence of HIV, malaria and unfavorable environmental factors.


Subject(s)
Antibodies/immunology , HIV Infections/epidemiology , HIV Infections/immunology , Maternal-Fetal Exchange/immunology , Placenta/immunology , Adult , Antigens/immunology , Antiretroviral Therapy, Highly Active , Female , Fetal Blood/immunology , HIV Infections/drug therapy , HIV Infections/virology , Humans , Immunity, Maternally-Acquired , Immunoglobulin G/immunology , Mozambique , Placenta/metabolism , Pregnancy , Protein Transport , Sex Factors , Vaccines/immunology , Young Adult
12.
Front. immunol ; 12: 1-18, mar 3, 2021. ilus, graf
Article in English | RSDM | ID: biblio-1526527

ABSTRACT

Transplacental transfer of antibodies is essential for conferring protection in newborns against infectious diseases. We assessed the impact of different factors, including gestational age and maternal infections such as HIV and malaria, on the efficiency of cord blood levels and placental transfer of IgG subclasses. We measured total IgG and IgG subclasses by quantitative suspension array technology against 14 pathogens and vaccine antigens, including targets of maternal immunization, in 341 delivering HIV-uninfected and HIV-infected mother-infant pairs from southern Mozambique. We analyzed the association of maternal HIV infection, Plasmodium falciparum exposure, maternal variables and pregnancy outcomes on cord antibody levels and transplacental transfer. Our results show that maternal antibody levels were the main determinant of cord antibody levels. Univariable and multivariable analysis showed that HIV reduced the placental transfer and cord levels of IgG and IgG1 principally, but also IgG2 to half of the antigens tested. P. falciparum exposure and prematurity were negatively associated with cord antibody levels and placental transfer, but this was antigen-subclass dependent. Our findings suggest that lower maternally transferred antibodies may underlie increased susceptibility to infections of HIV-exposed infants. This could affect efficacy of maternal vaccination, especially in sub-Saharan Africa, where there is a high prevalence of HIV, malaria and unfavorable environmental factors


Subject(s)
Humans , Placenta/immunology , Placenta/metabolism , Immunoglobulin G , HIV , Antibodies, Monoclonal , Schools, Nursery , Pregnancy , HIV Infections/virology , Blood-Borne Pathogens , Malaria
13.
Am J Trop Med Hyg ; 104(3): 1003-1012, 2021 01 18.
Article in English | MEDLINE | ID: mdl-33534758

ABSTRACT

Anemia is a common condition in HIV-infected children; however, its pathophysiology and the contribution of frequent causes of anemia such as iron deficiency (ID) and malaria are poorly understood. We carried out an ancillary study on the effect of HIV on anemia as part of a case-control study on risk factors of anemia among Mozambican children aged 1-59 months with documented HIV status. Of them, 390 children were admitted to the hospital with anemia (hemoglobin [Hb] < 11 g/dL), whereas 272 children without anemia (Hb ≥ 11 g/dL) were recruited in the community. We assessed differences by HIV status in the presentation of anemia etiological factors and the effect of HIV infection on the association of each factor with anemia. Among the 99 HIV-infected and 563 uninfected children included, HIV-infected anemic children had an increased risk of undernutrition (P < 0.0001), Epstein-Barr virus infection (P < 0.0001), bacteremia (P = 0.0060), a decreased risk of malaria (P < 0.0001), and a similar risk of ID (P = 0.7371) compared with anemic-uninfected children. HIV-infected children were significantly less likely to have anemia associated with Plasmodium falciparum hyperparasitemia (P = 0.0444) and had a lower prevalence of parasitemia in the bone marrow (BM) (P < 0.0001) than anemic-uninfected children. Levels of BM erythropoiesis and dyserythropoiesis were comparable between groups. These findings suggest that the pathophysiology of anemia among HIV-infected malaria-exposed children is not related to HIV-specific effects. For unclear reasons, HIV-infected children had reduced risk of malaria infection, whereas ID prevalence was comparable in HIV-infected and uninfected children, suggesting that iron supplementation recommendations should not be different in HIV-infected children.


Subject(s)
Anemia/etiology , Anemia/physiopathology , Comorbidity , HIV Infections/complications , Iron Deficiencies/complications , Iron Deficiencies/physiopathology , Malaria/complications , Anemia/epidemiology , Case-Control Studies , Child, Preschool , Female , HIV Infections/epidemiology , Humans , Infant , Infant, Newborn , Malaria/epidemiology , Male , Mozambique/epidemiology , Prevalence , Risk Assessment , Risk Factors
14.
J Infect ; 82(4): 45-57, 2021 04.
Article in English | MEDLINE | ID: mdl-33636218

ABSTRACT

OBJECTIVES: Maternal Plasmodium falciparum-specific antibodies may contribute to protect infants against severe malaria. Our main objective was to evaluate the impact of maternal HIV infection and placental malaria on the cord blood levels and efficiency of placental transfer of IgG and IgG subclasses. METHODS: In a cohort of 341 delivering HIV-negative and HIV-positive mothers from southern Mozambique, we measured total IgG and IgG subclasses in maternal and cord blood pairs by quantitative suspension array technology against eight P. falciparum antigens: Duffy-binding like domains 3-4 of VAR2CSA from the erythrocyte membrane protein 1, erythrocyte-binding antigen 140, exported protein 1 (EXP1), merozoite surface proteins 1, 2 and 5, and reticulocyte-binding-homologue-4.2 (Rh4.2). We performed univariable and multivariable regression models to assess the association of maternal HIV infection, placental malaria, maternal variables and pregnancy outcomes on cord antibody levels and antibody transplacental transfer. RESULTS: Maternal antibody levels were the main determinants of cord antibody levels. HIV infection and placental malaria reduced the transfer and cord levels of IgG and IgG1, and this was antigen-dependent. Low birth weight was associated with an increase of IgG2 in cord against EXP1 and Rh4.2. CONCLUSIONS: We found lower maternally transferred antibodies in HIV-exposed infants and those born from mothers with placental malaria, which may underlie increased susceptibility to malaria in these children.


Subject(s)
Antimalarials , HIV Infections , Malaria, Falciparum , Malaria , Antibodies, Protozoan , Child , Female , Humans , Infant , Malaria, Falciparum/epidemiology , Plasmodium falciparum , Pregnancy
15.
Front. immunol ; 12: 1-18, 2021. tab, fig
Article in English | RSDM | ID: biblio-1561692

ABSTRACT

Transplacental transfer of antibodies is essential for conferring protection in newborns against infectious diseases. We assessed the impact of different factors, including gestational age and maternal infections such as HIV and malaria, on the efficiency of cord blood levels and placental transfer of IgG subclasses. We measured total IgG and IgG subclasses by quantitative suspension array technology against 14 pathogens and vaccine antigens, including targets of maternal immunization, in 341 delivering HIV-uninfected and HIV-infected mother-infant pairs from southern Mozambique. We analyzed the association of maternal HIV infection, Plasmodium falciparum exposure, maternal variables and pregnancy outcomes on cord antibody levels and transplacental transfer. Our results show that maternal antibody levels were the main determinant of cord antibody levels. Univariable and multivariable analysis showed that HIV reduced the placental transfer and cord levels of IgG and IgG1 principally, but also IgG2 to half of the antigens tested. P. falciparum exposure and prematurity were negatively associated with cord antibody levels and placental transfer, but this was antigen-subclass dependent. Our findings suggest that lower maternally transferred antibodies may underlie increased susceptibility to infections of HIV-exposed infants. This could affect efficacy of maternal vaccination, especially in sub-Saharan Africa, where there is a high prevalence of HIV, malaria and unfavorable environmental factors.


Subject(s)
Humans , Male , Female , Pregnancy , Adolescent , Adult , HIV Infections/immunology , HIV Infections/epidemiology , Maternal-Fetal Exchange/immunology , Antibodies/immunology , Placenta/metabolism , Immunoglobulin G/immunology , Pregnancy , Vaccines/immunology , Carrier Proteins , HIV Infections/therapy , HIV Infections/virology , Sex Factors , Antiretroviral Therapy, Highly Active , Fetal Blood/immunology , Immunity, Maternally-Acquired , Antigens/immunology
16.
Glob Health Action ; 13(1): 1846903, 2020 12 31.
Article in English | MEDLINE | ID: mdl-33250013

ABSTRACT

Background: Monitoring Sustainable Development Goal indicators (SDGs) and their targets plays an important role in understanding and advocating for improved health outcomes for all countries. We present the United Nations (UN) Inter-agency groups' efforts to support countries to report on SDG health indicators, project progress towards 2030 targets and build country accountability for action. Objective: We highlight common principles and practices of each Inter-agency group and the progress made towards SDG 3 targets using seven health indicators as examples. The indicators used provide examples of best practice for modelling estimates and projections using standard methods, transparent data collection and country consultations. Methods: Practices common to the UN agencies include multi-UN agency participation, expert groups to advise on estimation methods, transparent publication of methods and data inputs, use of UN-derived population estimates, country consultations, and a common reporting platform to present results. Our seven examples illustrate how estimates, using mostly Bayesian models, make use of country data to track progress towards SDG targets for 2030. Results: Progress has been made over the past decade. However, none of the seven indicators are on track to achieve their respective SDG targets by 2030. Accelerated efforts are needed, especially in low- and middle-income countries, to reduce the burden of maternal, child, communicable and noncommunicable disease mortality, and to provide access to modern methods of family planning to all women. Conclusion: Our analysis shows the benefit of UN interagency monitoring which prioritizes transparent country data sources, UN population estimates and life tables, and rigorous but replicable modelling methods. Countries are supported to build capacity for data collection, analysis and reporting. Through these monitoring efforts we support countries to tackle even the most intransient health issues, including the pandemic caused by SARS-CoV-2 that is reversing the hard-earned gains of all countries.


Subject(s)
Global Health , Organizational Objectives , United Nations/organization & administration , Bayes Theorem , COVID-19/epidemiology , Child Health/standards , Communicable Diseases/epidemiology , Humans , Maternal Health/standards , Noncommunicable Diseases/epidemiology , Pandemics , SARS-CoV-2 , United Nations/standards
17.
Front Microbiol ; 11: 1452, 2020.
Article in English | MEDLINE | ID: mdl-32765436

ABSTRACT

Maternal factors and exposure to pathogens have an impact on infant health. For instance, HIV exposed but uninfected infants have higher morbidity and mortality than HIV unexposed infants. Innate responses are the first line of defense and orchestrate the subsequent adaptive immune response and are especially relevant in newborns. To determine the association of maternal HIV infection with maternal and newborn innate immunity we analyzed the cytokine responses upon pattern recognition receptor (PRR) stimulations in the triad of maternal peripheral and placental blood as well as in cord blood in a cohort of mother-infant pairs from southern Mozambique. A total of 48 women (35 HIV-uninfected and 13 HIV-infected) were included. Women and infant innate responses positively correlated with each other. Age, gravidity and sex of the fetus had some associations with spontaneous production of cytokines in the maternal peripheral blood. HIV-infected women not receiving antiretroviral therapy (ART) before pregnancy showed decreased IL-8 and IL-6 PRR responses in peripheral blood compared to those HIV-uninfected, and PRR hyporesponsiveness for IL-8 was also found in the corresponding infant's cord blood. HIV infection had a greater impact on placental blood responses, with significantly increased pro-inflammatory, T H 1 and T H 17 PRR responses in HIV-infected women not receiving ART before pregnancy compared to HIV-uninfected women. In conclusion, innate response of the mother and her newborn was altered by HIV infection in the women who did not receive ART before pregnancy. As these responses could be related to birth outcomes, targeted innate immune modulation could improve maternal and newborn health.

18.
Sci Transl Med ; 12(543)2020 05 13.
Article in English | MEDLINE | ID: mdl-32404508

ABSTRACT

Identifying immune correlates of protection and mechanisms of immunity accelerates and streamlines the development of vaccines. RTS,S/AS01E, the most clinically advanced malaria vaccine, has moderate efficacy in African children. In contrast, immunization with sporozoites under antimalarial chemoprophylaxis (CPS immunization) can provide 100% sterile protection in naïve adults. We used systems biology approaches to identifying correlates of vaccine-induced immunity based on transcriptomes of peripheral blood mononuclear cells from individuals immunized with RTS,S/AS01E or chemoattenuated sporozoites stimulated with parasite antigens in vitro. Specifically, we used samples of individuals from two age cohorts and three African countries participating in an RTS,S/AS01E pediatric phase 3 trial and malaria-naïve individuals participating in a CPS trial. We identified both preimmunization and postimmunization transcriptomic signatures correlating with protection. Signatures were validated in independent children and infants from the RTS,S/AS01E phase 3 trial and individuals from an independent CPS trial with high accuracies (>70%). Transcription modules revealed interferon, NF-κB, Toll-like receptor (TLR), and monocyte-related signatures associated with protection. Preimmunization signatures suggest that priming the immune system before vaccination could potentially improve vaccine immunogenicity and efficacy. Last, signatures of protection could be useful to determine efficacy in clinical trials, accelerating vaccine candidate testing. Nevertheless, signatures should be tested more extensively across multiple cohorts and trials to demonstrate their universal predictive capacity.


Subject(s)
Malaria Vaccines , Malaria, Falciparum , Malaria , Adult , Africa , Antibodies, Protozoan , Child , Humans , Immunization , Infant , Leukocytes, Mononuclear , Malaria/prevention & control , Malaria, Falciparum/prevention & control , Plasmodium falciparum
19.
Malar J ; 19(1): 141, 2020 Apr 08.
Article in English | MEDLINE | ID: mdl-32268917

ABSTRACT

BACKGROUND: As more countries progress towards malaria elimination, a better understanding of the most critical health system features for enabling and supporting malaria control and elimination is needed. METHODS: All available health systems data relevant for malaria control were collated from 23 online data repositories. Principal component analysis was used to create domain specific health system performance measures. Multiple regression model selection approaches were used to identify key health systems predictors of progress in malaria control in the 2000-2016 period among 105 countries. Additional analysis was performed within malaria burden groups. RESULTS: There was large heterogeneity in progress in malaria control in the 2000-2016 period. In univariate analysis, several health systems factors displayed a strong positive correlation with reductions in malaria burden between 2000 and 2016. In multivariable models, delivery of routine services and hospital capacity were strongly predictive of reductions in malaria cases, especially in high burden countries. In low-burden countries approaching elimination, primary health center density appeared negatively associated with progress while hospital capacity was positively correlated with eliminating malaria. CONCLUSIONS: The findings presented in this manuscript suggest that strengthening health systems can be an effective strategy for reducing malaria cases, especially in countries with high malaria burden. Potential returns appear particularly high in the area of service delivery.


Subject(s)
Disease Eradication/statistics & numerical data , Global Health/statistics & numerical data , Malaria/prevention & control , Humans , Regression Analysis
20.
J. infect. dis ; 221(2): 293-203, Jan 2. 2020. tab, graf, mapas
Article in English | AIM (Africa), RSDM | ID: biblio-1530922

ABSTRACT

Background: Innovative approaches are needed to limit antimalarial resistance evolution. Understanding the role of intermittent preventive treatment in pregnancy (IPTp) on the selection for resistance and the impact such selection has on pregnancy outcomes can guide future interventions. Methods: Plasmodium falciparum isolates (n = 914) from 2 randomized clinical trials were screened for pfmdr1 copy number variation and pfcrt, pfmdr1, pfdhfr, and pfdhps resistance markers. The trials were conducted between 2010 and 2013 in Benin, Gabon, Kenya, and Mozambique to establish the efficacy of IPTp-mefloquine (MQ) compared with IPTp-sulphadoxine-pyrimethamine (SP) in human immunodeficiency virus (HIV)-uninfected and to IPTp-placebo in HIV-infected women. Results: In HIV-uninfected women, the prevalence of pfcrt mutants, pfdhfr/pfdhps quintuple mutants, and pfmdr1 copy number was similar between women receiving IPT-SP and IPTp-MQ. However, prevalence of pfmdr1 polymorphism 86Y was lower in the IPTp-MQ group than in the IPTp-SP group, and within the IPTp-MQ group it was lower at delivery compared with recruitment. No effect of IPTp-MQ on resistance markers was observed among HIV-infected women. The carriage of resistance markers was not associated with pregnancy outcomes.


Subject(s)
Humans , Female , Pregnancy , Adult , Young Adult , Malaria, Falciparum/drug therapy , Malaria, Falciparum/blood , Drug Resistance, Multiple/drug effects , Antimalarials/therapeutic use , Polymorphism, Genetic , Mefloquine/therapeutic use , Drug Combinations , Malaria/epidemiology
SELECTION OF CITATIONS
SEARCH DETAIL