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Featured researches published by Seth Owusu-Agyei.


Pediatrics | 2006

Delayed Breastfeeding Initiation Increases Risk of Neonatal Mortality.

Karen Edmond; Charles Zandoh; Maria A. Quigley; Seeba Amenga-Etego; Seth Owusu-Agyei; Betty Kirkwood

BACKGROUND. Breastfeeding promotion is a key child survival strategy. Although there is an extensive scientific basis for its impact on postneonatal mortality, evidence is sparse for its impact on neonatal mortality. OBJECTIVES. We sought to assess the contribution of the timing of initiation of breastfeeding to any impact. METHODS. This study took advantage of the 4-weekly surveillance system from a large ongoing maternal vitamin A supplementation trial in rural Ghana involving all women of childbearing age and their infants. It was designed to evaluate whether timing of initiation of breastfeeding and type (exclusive, predominant, or partial) are associated with risk of neonatal mortality. The analysis is based on 10947 breastfed singleton infants born between July 2003 and June 2004 who survived to day 2 and whose mothers were visited in the neonatal period. RESULTS. Breastfeeding was initiated within the first day of birth in 71% of infants and by the end of day 3 in all but 1.3% of them; 70% were exclusively breastfed during the neonatal period. The risk of neonatal death was fourfold higher in children given milk-based fluids or solids in addition to breast milk. There was a marked dose response of increasing risk of neonatal mortality with increasing delay in initiation of breastfeeding from 1 hour to day 7; overall late initiation (after day 1) was associated with a 2.4-fold increase in risk. The size of this effect was similar when the model was refitted excluding infants at high risk of death (unwell on the day of birth, congenital abnormalities, premature, unwell at the time of interview) or when deaths during the first week (days 2–7) were excluded. CONCLUSIONS. Promotion of early initiation of breastfeeding has the potential to make a major contribution to the achievement of the child survival millennium development goal; 16% of neonatal deaths could be saved if all infants were breastfed from day 1 and 22% if breastfeeding started within the first hour. Breastfeeding-promotion programs should emphasize early initiation as well as exclusive breastfeeding. This has particular relevance for sub-Saharan Africa, where neonatal and infant mortality rates are high but most women already exclusively or predominantly breastfeed their infants.


The Lancet | 2009

Efficacy and safety of intermittent preventive treatment with sulfadoxine-pyrimethamine for malaria in African infants: a pooled analysis of six randomised, placebo-controlled trials

John J. Aponte; David Schellenberg; Andrea Egan; Alasdair Breckenridge; Ilona Carneiro; Julia Critchley; Ina Danquah; Alexander Dodoo; Robin Kobbe; Bertrand Lell; Jürgen May; Zul Premji; Sergi Sanz; Esperanza Sevene; Rachida Soulaymani-Becheikh; Peter Winstanley; Samuel Adjei; Sylvester D. Anemana; Daniel Chandramohan; Saadou Issifou; Frank P. Mockenhaupt; Seth Owusu-Agyei; Brian Greenwood; Martin P. Grobusch; Peter G. Kremsner; Eusebio Macete; Hassan Mshinda; Robert D. Newman; Laurence Slutsker; Marcel Tanner

BACKGROUND Intermittent preventive treatment (IPT) is a promising strategy for malaria control in infants. We undertook a pooled analysis of the safety and efficacy of IPT in infants (IPTi) with sulfadoxine-pyrimethamine in Africa. METHODS We pooled data from six double-blind, randomised, placebo-controlled trials (undertaken one each in Tanzania, Mozambique, and Gabon, and three in Ghana) that assessed the efficacy of IPTi with sulfadoxine-pyrimethamine. In all trials, IPTi or placebo was given to infants at the time of routine vaccinations delivered by WHOs Expanded Program on Immunization. Data from the trials for incidence of clinical malaria, risk of anaemia (packed-cell volume <25% or haemoglobin <80 g/L), and incidence of hospital admissions and adverse events in infants up to 12 months of age were reanalysed by use of standard outcome definitions and time periods. Analysis was by modified intention to treat, including all infants who received at least one dose of IPTi or placebo. FINDINGS The six trials provided data for 7930 infants (IPTi, n=3958; placebo, n=3972). IPTi had a protective efficacy of 30.3% (95% CI 19.8-39.4, p<0.0001) against clinical malaria, 21.3% (8.2-32.5, p=0.002) against the risk of anaemia, 38.1% (12.5-56.2, p=0.007) against hospital admissions associated with malaria parasitaemia, and 22.9% (10.0-34.0, p=0.001) against all-cause hospital admissions. There were 56 deaths in the IPTi group compared with 53 in the placebo group (rate ratio 1.05, 95% CI 0.72-1.54, p=0.79). One death, judged as possibly related to IPTi because it occurred 19 days after a treatment dose, was subsequently attributed to probable sepsis. Four of 676 non-fatal hospital admissions in the IPTi group were deemed related to study treatment compared with five of 860 in the placebo group. None of three serious dermatological adverse events in the IPTi group were judged related to study treatment compared with one of 13 in the placebo group. INTERPRETATION IPTi with sulfadoxine-pyrimethamine was safe and efficacious across a range of malaria transmission settings, suggesting that this intervention is a useful contribution to malaria control. FUNDING Bill & Melinda Gates Foundation.


BMJ | 2005

Cluster randomised trial of intermittent preventive treatment for malaria in infants in area of high, seasonal transmission in Ghana.

Daniel Chandramohan; Seth Owusu-Agyei; Ilona Carneiro; Timothy Awine; Kwame Amponsa-Achiano; Nathan Mensah; Shabbar Jaffar; Rita Baiden; Abraham Hodgson; Fred Binka; Brian Greenwood

Abstract Objective To evaluate the effects of intermittent preventive treatment for malaria in infants (IPTi) with sulfadoxine-pyrimethamine in an area of intense, seasonal transmission. Design Cluster randomised placebo controlled trial, with 96 clusters allocated randomly to sulfadoxine-pyrimethamine or placebo in blocks of eight. Interventions Children received sulfadoxine-pyrimethamine or placebo and one month of iron supplementation when they received DPT-2, DPT-3, or measles vaccinations and at 12 months of age. Main outcome measures Incidence of malaria and of anaemia determined through passive case detection. Results 89% (1103/1242) of children in the placebo group and 88% (1088/1243) in the IPTi group completed follow-up to 24 months of age. The protective efficacy of IPTi against all episodes of malaria was 24.8% (95% confidence interval 14.3% to 34.0%) up to 15 months of age. IPTi had no protective effect against malaria between 16 and 24 months of age (protective efficacy −4.9%, −21.3% to 9.3%). The incidence of high parasite density malaria (≥ 5000 parasites/μl) was higher in the IPTi group than in the placebo group between 16 and 24 months of age (protective efficacy −19.5%, −39.8% to −2.2%). IPTi reduced hospital admissions with anaemia by 35.1% (10.5% to 52.9%) up to 15 months of age. IPTi had no significant effect on anaemia between 16 and 24 months of age (protective efficacy −6.4%, −76.8% to 35.9%). The relative risk of death up to 15 months of age in the IPTi group was 1.26 (95% confidence interval 0.81 to 1.96; P =0.31), and from 16 to 24 months it was 1.28 (0.77 to 2.14; P =0.35). Conclusions Intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine can reduce malaria and anaemia in infants even in seasonal, high transmission areas, but concern exists about possible rebound in the incidence of malaria in the second year of life.


PLOS Medicine | 2009

Multiple Origins and Regional Dispersal of Resistant dhps in African Plasmodium falciparum Malaria.

Richard Pearce; Hirva Pota; Marie-Solange Evehe; El-Hadj Bâ; Ghyslain Mombo-Ngoma; Allen L Malisa; Rosalynn Ord; Walter Inojosa; Alexandre Matondo; Diadier Diallo; Wilfred F. Mbacham; Ingrid van den Broek; Todd Swarthout; Asefaw Getachew; Seyoum Dejene; Martin P. Grobusch; Fanta Njie; Samuel K. Dunyo; Margaret Kweku; Seth Owusu-Agyei; Daniel Chandramohan; Maryline Bonnet; Jean-Paul Guthmann; Sîan E. Clarke; Karen I. Barnes; Elizabeth Streat; Stark Katokele; Petrina Uusiku; Chris O. Agboghoroma; Olufunmilayo Y. Elegba

Cally Roper and colleagues analyze the distribution of sulfadoxine resistance mutations and flanking microsatellite loci to trace the emergence and dispersal of drug-resistant Plasmodium falciparum malaria in Africa.


Lancet Neurology | 2013

Prevalence of active convulsive epilepsy in sub-Saharan Africa and associated risk factors: Cross-sectional and case-control studies

Anthony K. Ngugi; Christian Bottomley; Immo Kleinschmidt; Ryan G. Wagner; Angelina Kakooza-Mwesige; Kenneth Ayuurebobi Ae-Ngibise; Seth Owusu-Agyei; Honorati Masanja; Gathoni Kamuyu; Rachael Odhiambo; Eddie Chengo; Josemir W. Sander; Charles R. Newton

Summary Background The prevalence of epilepsy in sub-Saharan Africa seems to be higher than in other parts of the world, but estimates vary substantially for unknown reasons. We assessed the prevalence and risk factors of active convulsive epilepsy across five centres in this region. Methods We did large population-based cross-sectional and case-control studies in five Health and Demographic Surveillance System centres: Kilifi, Kenya (Dec 3, 2007–July 31, 2008); Agincourt, South Africa (Aug 4, 2008–Feb 27, 2009); Iganga-Mayuge, Uganda (Feb 2, 2009–Oct 30, 2009); Ifakara, Tanzania (May 4, 2009–Dec 31, 2009); and Kintampo, Ghana (Aug 2, 2010–April 29, 2011). We used a three-stage screening process to identify people with active convulsive epilepsy. Prevalence was estimated as the ratio of confirmed cases to the population screened and was adjusted for sensitivity and attrition between stages. For each case, an age-matched control individual was randomly selected from the relevant centres census database. Fieldworkers masked to the status of the person they were interviewing administered questionnaires to individuals with active convulsive epilepsy and control individuals to assess sociodemographic variables and historical risk factors (perinatal events, head injuries, and diet). Blood samples were taken from a randomly selected subgroup of 300 participants with epilepsy and 300 control individuals from each centre and were screened for antibodies to Toxocara canis, Toxoplasma gondii, Onchocerca volvulus, Plasmodium falciparum, Taenia solium, and HIV. We estimated odds ratios (ORs) with logistic regression, adjusted for age, sex, education, employment, and marital status. Results 586 607 residents in the study areas were screened in stage one, of whom 1711 were diagnosed as having active convulsive epilepsy. Prevalence adjusted for attrition and sensitivity varied between sites: 7·8 per 1000 people (95% CI 7·5–8·2) in Kilifi, 7·0 (6·2–7·4) in Agincourt, 10·3 (9·5–11·1) in Iganga-Mayuge, 14·8 (13·8–15·4) in Ifakara, and 10·1 (9·5–10·7) in Kintampo. The 1711 individuals with the disorder and 2032 control individuals were given questionnaires. In children (aged <18 years), the greatest relative increases in prevalence were associated with difficulties feeding, crying, or breathing after birth (OR 10·23, 95% CI 5·85–17·88; p<0·0001); abnormal antenatal periods (2·15, 1·53–3·02; p<0·0001); and head injury (1·97, 1·28–3·03; p=0·002). In adults (aged ≥18 years), the disorder was significantly associated with admission to hospital with malaria or fever (2·28, 1·06–4·92; p=0·036), exposure to T canis (1·74, 1·27–2·40; p=0·0006), exposure to T gondii (1·39, 1·05–1·84; p=0·021), and exposure to O volvulus (2·23, 1·56–3·19; p<0·0001). Hypertension (2·13, 1·08–4·20; p=0·029) and exposure to T solium (7·03, 2·06–24·00; p=0·002) were risk factors for adult-onset disease. Interpretation The prevalence of active convulsive epilepsy varies in sub-Saharan Africa and that the variation is probably a result of differences in risk factors. Programmes to control parasitic diseases and interventions to improve antenatal and perinatal care could substantially reduce the prevalence of epilepsy in this region. Funding Wellcome Trust, University of the Witwatersrand, and South African Medical Research Council.


Tropical Medicine & International Health | 2004

Malaria transmission dynamics at a site in northern Ghana proposed for testing malaria vaccines.

Maxwell A. Appawu; Seth Owusu-Agyei; Samuel Dadzie; Victor Asoala; Francis Anto; Kwadwo A. Koram; William O. Rogers; Francis K. Nkrumah; Stephen L. Hoffman; David J. Fryauff

We studied the malaria transmission dynamics in Kassena Nankana district (KND), a site in northern Ghana proposed for testing malaria vaccines. Intensive mosquito sampling for 1 year using human landing catches in three micro‐ecological sites (irrigated, lowland and rocky highland) yielded 18 228 mosquitoes. Anopheles gambiae s.l. and Anopheles funestus constituted 94.3% of the total collection with 76.8% captured from the irrigated communities. Other species collected but in relatively few numbers were Anopheles pharoensis (5.4%) and Anopheles rufipes (0.3%). Molecular analysis of 728 An. gambiae.s.l. identified Anopheles gambiae s.s. as the most dominant sibling species (97.7%) of the An. gambiae complex from the three ecological sites. Biting rates of the vectors (36.7 bites per man per night) were significantly higher (P < 0.05) in the irrigated area than in the non‐irrigated lowland (5.2) and rocky highlands (5.9). Plasmodium falciparum sporozoite rates of 7.2% (295/4075) and 7.1% (269/3773) were estimated for An. gambiae s.s. and An. funestus, respectively. Transmission was highly seasonal, and the heaviest transmission occurred from June to October. The intensity of transmission was higher for people in the irrigated communities than the non‐irrigated ones. An overall annual entomological inoculation rate (EIR) of 418 infective bites was estimated in KND. There were micro‐ecological variations in the EIRs, with values of 228 infective bites in the rocky highlands, 360 in the lowlands and 630 in the irrigated area. Approximately 60% of malaria transmission in KND occurred indoors during the second half of the night, peaking at daybreak between 04.00 and 06.00 hours. Vaccine trials could be conducted in this district, with timing dependent on the seasonal patterns and intensity of transmission taking into consideration the micro‐geographical differences and vaccine trial objectives.


The Lancet | 2013

Effect of the Newhints home-visits intervention on neonatal mortality rate and care practices in Ghana: a cluster randomised controlled trial

Betty Kirkwood; Alexander Manu; Augustinus ten Asbroek; Seyi Soremekun; Benedict Weobong; Thomas Gyan; Samuel Danso; Seeba Amenga-Etego; Charlotte Tawiah-Agyemang; Seth Owusu-Agyei; Zelee Hill

BACKGROUND In 2009, on the basis of promising evidence from trials in south Asia, WHO and UNICEF issued a joint statement about home visits as a strategy to improve newborn survival. In the Newhints trial, we aimed to test this home-visits strategy in sub-Saharan Africa by assessing the effect on all-cause neonatal mortality rate (NMR) and essential newborn-care practices. METHODS The Newhints cluster randomised trial was undertaken in 98 zones in seven districts in the Brong Ahafo Region, Ghana. 49 zones were randomly assigned to the Newhints intervention and 49 to the control intervention by use of restricted randomisation with stratification to ensure comparability between interventions. Community-based surveillance volunteers (CBSVs) in Newhints zones were trained to identify pregnant women in their community and to make two home visits during pregnancy and three in the first week of life to promote essential newborn-care practices, weigh and assess babies for danger signs, and refer as necessary. Primary outcomes were NMR and coverage of key essential newborn-care practices. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00623337. FINDINGS 16,168 (99%) of 16,329 deliveries between November, 2008, and December, 2009, were livebirths; the status at 1 month was known for 15,619 (97%) livebirths. 482 neonatal deaths were recorded. Coverage data were available from 6029 women in Newhints zones; of these 4358 (72%) reported having CBSV visits during pregnancy and 3815 (63%) reported having postnatal visits. This coverage increased substantially from June, 2009, after the introduction of new implementation strategies and reached almost 90% for pregnancy visits by the end of the trial and 75% for postnatal visits. The Newhints intervention significantly increased coverage of key essential newborn-care behaviours, except for four or more antenatal-care visits (5975 [76%] of 7859 vs 5988 [74%] of 8121, respectively; relative risk 1·02, 95% CI 0·96-1·09; p=0·52) and baby delivered in a facility (5373 [68%] vs 5539 [68%], respectively; 0·97, 0·81-1·14; p=0·69). The largest increase was for care-seeking, with 102 (77%) of 132 sick babies in Newhints zones taken to a hospital or clinic compared with 77 (55%) of 139 in control zones (1·43, 1·17-1·76; p=0·001). Increases were also noted in bednet use during pregnancy (5398 [69%] of 7859 vs 5135 [63%] of 8121, respectively; 1·12, 1·03-1·21; p=0·005), money saved for delivery or emergency (5730 [86%] of 6681 vs 5525 [80%] of 6941, respectively; 1·09, 1·05-1·12; p<0·0001), transport arranged in advance for facility (2496 [37%] vs 2061 [30%], respectively; 1·30, 1·12-1·49; p=0·0004), birth assistant for home delivery washed hands with soap (1853 [93%] of 1992 vs 1817 [87%] of 2091, respectively; 1·05, 1·02-1·09; p=0·001), initiation of breastfeeding in less than 1 h of birth (3743 [49%] of 7673 vs 3280 [41%] of 7921, respectively; 1·22, 1·07-1·40; p=0·004), skin to skin contact (3355 [44%] vs 1931 [24%], respectively; 2·30, 1·85-2·87; p=0·0002), first bath delayed for longer than 6 h (3131 [41%] vs 2269 [29%], respectively; 1·65, 1·27-2·13; p<0·0001), exclusive breastfeeding for 26-32 days (1217 [86%] of 1414 vs 1091 [80%] of 1371; 1·10, 1·04-1·16; p=0·001), and baby sleeping under bednet for 8-56 days (4548 [79%] of 5756 vs 4291 [73%] of 5846; 1·09, 1·03-1·15; p=0·002). There were 230 neonatal deaths in the Newhints zones compared with 252 in the control zones. The overall NMRs per 1000 livebirths were 29·8 and 31·9, respectively (0·92, 0·75-1·12; p=0·405). INTERPRETATION The reduction in NMR with Newhints is consistent with the reductions achieved in three trials undertaken in programme settings in south Asia. Because there is no suggestion of any heterogeneity (p=0·850) between these trials and Newhints, the meta-analysis summary estimate of a reduction of 12% (95% CI 5-18) provides the best evidence for the likely effect of the home-visits strategy delivered within programmes in sub-Saharan Africa and in south Asia. Improvements in the quality of delivery and neonatal care in health facilities and development of innovative, effective strategies to increase coverage of home visits on the day of birth could lead to the achievement of more substantial reductions. FUNDING WHO, Bill & Melinda Gates Foundation, and UK Department for International Development.


The New England Journal of Medicine | 2015

Genetic diversity and protective efficacy of the RTS,S/AS01 malaria vaccine

Daniel E. Neafsey; Michal Juraska; Trevor Bedford; David Benkeser; Clarissa Valim; Allison D. Griggs; Marc Lievens; Salim Abdulla; Samuel Adjei; Tsiri Agbenyega; Selidji Todagbe Agnandji; Pedro Aide; Scott Anderson; Daniel Ansong; John J. Aponte; Kwaku Poku Asante; Philip Bejon; Ashley J. Birkett; Myriam Bruls; Kristen M. Connolly; Umberto D'Alessandro; Carlota Dobaño; Samwel Gesase; Brian Greenwood; Jonna Grimsby; Halidou Tinto; Mary J. Hamel; Irving Hoffman; Portia Kamthunzi; Simon Kariuki

BACKGROUND The RTS,S/AS01 vaccine targets the circumsporozoite protein of Plasmodium falciparum and has partial protective efficacy against clinical and severe malaria disease in infants and children. We investigated whether the vaccine efficacy was specific to certain parasite genotypes at the circumsporozoite protein locus. METHODS We used polymerase chain reaction-based next-generation sequencing of DNA extracted from samples from 4985 participants to survey circumsporozoite protein polymorphisms. We evaluated the effect that polymorphic positions and haplotypic regions within the circumsporozoite protein had on vaccine efficacy against first episodes of clinical malaria within 1 year after vaccination. RESULTS In the per-protocol group of 4577 RTS,S/AS01-vaccinated participants and 2335 control-vaccinated participants who were 5 to 17 months of age, the 1-year cumulative vaccine efficacy was 50.3% (95% confidence interval [CI], 34.6 to 62.3) against clinical malaria in which parasites matched the vaccine in the entire circumsporozoite protein C-terminal (139 infections), as compared with 33.4% (95% CI, 29.3 to 37.2) against mismatched malaria (1951 infections) (P=0.04 for differential vaccine efficacy). The vaccine efficacy based on the hazard ratio was 62.7% (95% CI, 51.6 to 71.3) against matched infections versus 54.2% (95% CI, 49.9 to 58.1) against mismatched infections (P=0.06). In the group of infants 6 to 12 weeks of age, there was no evidence of differential allele-specific vaccine efficacy. CONCLUSIONS These results suggest that among children 5 to 17 months of age, the RTS,S vaccine has greater activity against malaria parasites with the matched circumsporozoite protein allele than against mismatched malaria. The overall vaccine efficacy in this age category will depend on the proportion of matched alleles in the local parasite population; in this trial, less than 10% of parasites had matched alleles. (Funded by the National Institutes of Health and others.).


JAMA | 2013

Effect of Iron Fortification on Malaria Incidence in Infants and Young Children in Ghana: A Randomized Trial

Stanley Zlotkin; Samuel Newton; Ashley M Aimone; Irene T Azindow; Seeba Amenga-Etego; Kofi Tchum; Emmanuel Mahama; Kevin E. Thorpe; Seth Owusu-Agyei

IMPORTANCE In sub-Saharan Africa, malaria is a leading cause of childhood morbidity and iron deficiency is among the most prevalent nutritional deficiencies. In 2006, the World Health Organization and the United Nations Childrens Fund released a joint statement that recommended limiting use of iron supplements (tablets or liquids) among children in malaria-endemic areas because of concern about increased malaria risk. As a result, anemia control programs were either not initiated or stopped in these areas. OBJECTIVE To determine the effect of providing a micronutrient powder (MNP) with or without iron on the incidence of malaria among children living in a high malaria-burden area. DESIGN, SETTING, AND PARTICIPANTS Double-blind, cluster randomized trial of children aged 6 to 35 months (n = 1958 living in 1552 clusters) conducted over 6 months in 2010 in a rural community setting in central Ghana, West Africa. A cluster was defined as a compound including 1 or more households. Children were excluded if iron supplement use occurred within the past 6 months, they had severe anemia (hemoglobin level <7 g/dL), or severe wasting (weight-for-length z score <-3). INTERVENTIONS Children were randomized by cluster to receive a MNP with iron (iron group; 12.5 mg/d of iron) or without iron (no iron group). The MNP with and without iron were added to semiliquid home-prepared foods daily for 5 months followed by 1-month of further monitoring. Insecticide-treated bed nets were provided at enrollment, as well as malaria treatment when indicated. MAIN OUTCOMES AND MEASURES Malaria episodes in the iron group compared with the no iron group during the 5-month intervention period. RESULTS In intention-to-treat analyses, malaria incidence overall was significantly lower in the iron group compared with the no iron group (76.1 and 86.1 episodes/100 child-years, respectively; risk ratio (RR), 0.87 [95% CI, 0.79-0.97]), and during the intervention period (79.4 and 90.7 episodes/100 child-years, respectively; RR, 0.87 [95% CI, 0.78-0.96]). In secondary analyses, these differences were no longer statistically significant after adjusting for baseline iron deficiency and anemia status overall (adjusted RR, 0.87; 95% CI, 0.75-1.01) and during the intervention period (adjusted RR, 0.86; 95% CI, 0.74-1.00). CONCLUSION AND RELEVANCE In a malaria-endemic setting in which insecticide-treated bed nets were provided and appropriate malaria treatment was available, daily use of a MNP with iron did not result in an increased incidence of malaria among young children. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01001871.


Lancet Infectious Diseases | 2011

Safety and efficacy of the RTS,S/AS01E candidate malaria vaccine given with expanded-programme-on-immunisation vaccines: 19 month follow-up of a randomised, open-label, phase 2 trial

Kwaku Poku Asante; Salim Abdulla; Selidji Todagbe Agnandji; John Lyimo; Johan Vekemans; Solange Soulanoudjingar; Ruth Owusu; Mwanajaa Shomari; Amanda Leach; Erik Jongert; Nahya Salim; José Francisco Fernandes; David Dosoo; Maria Chikawe; Saadou Issifou; Kingsley Osei-Kwakye; Marc Lievens; Tina Möller; Stephen Apanga; Grace Mwangoka; Marie-Claude Dubois; Tigani Madi; Evans Kwara; Rose Minja; Aurore B. Hounkpatin; Owusu Boahen; Kingsley Kayan; George Adjei; Daniel Chandramohan; Terrell Carter

BACKGROUND The RTS,S/AS01(E) candidate malaria vaccine is being developed for immunisation of infants in Africa through the expanded programme on immunisation (EPI). 8 month follow-up data have been reported for safety and immunogenicity of RTS,S/AS01(E) when integrated into the EPI. We report extended follow-up to 19 months, including efficacy results. METHODS We did a randomised, open-label, phase 2 trial of safety and efficacy of the RTS,S/AS01(E) candidate malaria vaccine given with EPI vaccines between April 30, 2007, and Oct 7, 2009, in Ghana, Tanzania, and Gabon. Eligible children were 6-10 weeks of age at first vaccination, without serious acute or chronic illness. All children received the EPI diphtheria, tetanus, pertussis (inactivated whole-cell), and hepatitis-B vaccines, Haemophilus influenzae type b vaccine, and oral polio vaccine at study months 0, 1, and 2, and measles vaccine and yellow fever vaccines at study month 7. Participants were randomly assigned (1:1:1) to receive three doses of RTS,S/AS01(E) at 6, 10, and 14 weeks (0, 1, 2 month schedule) or at 6 weeks, 10 weeks, and 9 months (0, 2, 7 month schedule) or placebo. Randomisation was according to a predefined block list with a computer-generated randomisation code. Detection of serious adverse events and malaria was by passive case detection. Antibodies against Plasmodium falciparum circumsporozoite protein and HBsAg were monitored for 19 months. This study is registered with ClinicalTrials.gov, number NCT00436007. FINDINGS 511 children were enrolled. Serious adverse events occurred in 57 participants in the RTS,S/AS01(E) 0, 1, 2 month group (34%, 95% CI 27-41), 47 in the 0, 1, 7 month group (28%, 21-35), and 49 (29%, 22-36) in the control group; none were judged to be related to study vaccination. At month 19, anticircumsporozoite immune responses were significantly higher in the RTS,S/AS01(E) groups than in the control group. Vaccine efficacy for the 0, 1, 2 month schedule (2 weeks after dose three to month 19, site-adjusted according-to-protocol analysis) was 53% (95% CI 26-70; p=0·0012) against first malaria episodes and 59% (36-74; p=0·0001) against all malaria episodes. For the entire study period, (total vaccinated cohort) vaccine efficacy against all malaria episodes was higher with the 0, 1, 2 month schedule (57%, 95% CI 33-73; p=0·0002) than with the 0, 1, 7 month schedule (32% CI 16-45; p=0·0003). 1 year after dose three, vaccine efficacy against first malaria episodes was similar for both schedules (0, 1, 2 month group, 61·6% [95% CI 35·6-77·1], p<0·001; 0, 1, 7 month group, 63·8% [40·4-78·0], p<0·001, according-to-protocol cohort). INTERPRETATION Vaccine efficacy was consistent with the target put forward by the WHO-sponsored malaria vaccine technology roadmap for a first-generation malaria vaccine. The 0, 1, 2 month vaccine schedule has been selected for phase 3 candidate vaccine assessment. FUNDING Program for Appropriate Technology in Health Malaria Vaccine Initiative; GlaxoSmithKline Biologicals.

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