Double stigma: a cross-sectional study of Lassa patients with hearing loss in North Central Nigeria.

Introduction: Lassa fever is a zoonotic infectious disease endemic in West Africa with a high case-fatality rate and reported stigmatization of surviving patients. This study examines discrimination among survivors of Lassa fever (LF) complicated by hearing loss (HL). Methods: This cross-sectional qualitative study used an in-depth interview guide to collect information from patients with HL about their experience of stigma. Interviews were conducted by a trained team of interviewers at the Jos University Teaching Hospital between January and April 2022 in Hausa language after informed consent was obtained. Recordings of the interviews were transcribed and translated from Hausa to English. Data analysis was conducted using NVivo software using a thematic framework approach. Results: Most (73%) respondents were male (n = 11); 27% were female (n = 4). The median age was 35 years (interquartile range, 16.5). Some Lassa fever patients experienced stigma and discrimination (53%) including isolation and withdrawal of family and community support during and after illness. HL increased stigma, as some patients were labeled "deaf" by other community members, increasing perceived stigma and devaluation. HL affected the socio-economic wellbeing of some who could not communicate well with their families and customers and constrained social interactions, evoking pain and apathy. Some survivors of LF and victims of its sequelae of HL experienced double stigmatization. While they were ill with LF, a third of respondents reported avoidance and isolation by family and community members who withdrew care and support both to them and their close family members. These forms of stigmatization strained their relationships. Conclusion: There is a need to address stigma in LF survivors who develop HL through concerted community-owned awareness to improve their quality of life along with a robust social support system to aid prevention.

Antenatal jaundice instruction and acute bilirubin encephalopathy in Nigeria.

BACKGROUND: Acute Bilirubin Encephalopathy (ABE) is common in Nigeria. Parents' inability to recognize jaundice and delays in seeking care are significant barriers to its prevention. METHODS: We compared associations of (1) interactive antenatal maternal jaundice instruction with postnatal reinforcement, (2) standard postnatal instruction, and (3) no maternal instruction with the incidence of ABE among 647 jaundice admissions stratified for risk factors identified in initial descriptive analysis. RESULTS: Eighty-three (83/647;12.8%) admissions developed ABE including eleven jaundice-related deaths. ABE was present at admission in 20/22 (90.9%) if mothers received no jaundice instruction and no antenatal care, 42/182 (23.1%) if received antenatal care but no instruction, 16/95 (16.8%) if received postnatal instruction only, and 4/337 (1.2%) if mothers received both antenatal and postnatal instruction (p < .001). ABE was highly associated with out-of-hospital delivery, number of antenatal clinic visits, and birth attendant, but these risks were mitigated by antenatal/postnatal instruction. Admission rates with bilirubin levels below treatment guidelines (12 mg/dL) were higher following instruction (30.7%) than with no instruction (14.4%). Limiting subjects to those meeting admission criteria increased ABE rates in all groups without altering conclusions. CONCLUSION: Interactive antenatal instruction with postnatal reinforcement resulted in timely care seeking and a lower incidence of ABE. IMPACT: Empowering mothers to participate in neonatal jaundice management is critical in low-income countries where jaundice monitoring and follow up are unreliable. Instructing mothers about jaundice in antenatal clinics with postnatal reinforcement is more effective than standard postpartum instruction in facilitating jaundice detection, timely care seeking, and lowering the incidence of acute bilirubin encephalopathy (ABE). Antenatal training also mitigates risks for ABE associated with out-of-hospital deliveries, limited antenatal care, and unskilled birth attendants. IMPACT: Adding structured jaundice instruction in antenatal clinics could greatly reduce bilirubin induced brain injury in countries where ABE is common.

SEROPROTECTION RATE OF HAEMOPHILUS INFLUENZAE TYPE B CONJUGATE VACCINE AND ASSOCIATED CLINICAL OUTCOMES AMONG NIGERIAN CHILDREN AGED 6 TO 23 MONTHS.

Introduction: Haemophilus influenzae type b (Hib) causes invasive infections almost exclusively in under- fives with those aged 6-23 months being the most vulnerable. In Nigeria, it is estimated to cause nearly 400,000 annual infections and another 30,000 under-five mortality attributable to pneumonia and meningitis alone. The Hib Conjugate Vaccine (HCV) is in widespread use to combat these devastating infections. Data on its impact in Nigeria is grossly scanty. This study evaluated the seroprotection rates (SPR) of HCV and associated clinical outcomes among children aged 6-23 months in Obi L.G.A. of Nasarawa State, Nigeria. Methods: A cross-sectional study of 267 children aged 6-23 months who had completed three doses of HCV. They were enrolled via a two-staged household-level cluster sampling. Relevant sociodemographic and clinical data were obtained using structured questionnaires and serum samples collected were analysed serologically for antipolyribosylribitol phosphate (anti-PRP) antibodies using ELISA. Results: The overall SPRs against invasive Hib disease and Hib nasopharyngeal colonization were 74.2% and 26.2%, respectively. The overall geometric mean titre (GMT) of anti-PRP was 1.85 µg/mL (95%CI: 1.60-2.14) and across age groups, GMTs were >1 µg/mL-the threshold for long-term protection against invasive Hib disease. Rates/duration of healthcare admissions and average episodes of probable Hib disease syndromes were lower in seroprotected but not statistically different from non-seroprotected children. Conclusion: The demonstrated anti-PRP titres and Seroprotection Rates infer a very good HCV efficacy in Nigerian children. The lack of significant difference in clinical outcomes may be attributable to nonspecificity.

FACTORS INFLUENCING ANTI-POLYRIBOSYLRIBITOL PHOSPHATE TITRES IN YOUNG NIGERIAN CHILDREN PRIMED WITH DTWP-HEPB-HIB VACCINE.

Introduction: Recent research suggests that variation in vaccine-induced immune responses is influenced by genetic, nutritional, environmental, and vaccine-related factors, with significant vaccine design and programmatic policy implications. Haemophilus influenzae type b (Hib) Conjugate Vaccine (HCV) stimulates the production of antiPolyribosylribitol phosphate (anti-PRP) antibodies, which confer long-term protection against invasive Hib disease and nasopharyngeal colonization by Hib at titre levels ≥1µg/mL and ≥5µg/mL respectively. This study investigated the influence of these factors on the protective anti-PRP levels in children aged 6-23 months in Obi L.G.A. of Nasarawa State, Nigeria. Methods: The study was a cross-sectional, two-stage household-level cluster survey involving 267 children who had completed the E.P.I. schedule of HCV-containing DTwP-HepB-Hib. Validated questionnaires were used for enrolment and relevant clinical and laboratory evaluations including anti-PRP, ABO/Rhesus antigens, and Haemoglobin genotype assays were conducted. Regression analyses were performed using Stata to explore the correlation between sociodemographic/vaccine-related factors, nutritional status, genotype, ABO/Rhesus antigens, and protective anti-PRP titres. Results: Bivariate analysis showed that age, breastfeeding practice, household size/under-five number, nutritional, socioeconomic, Measles/Yellow fever vaccination, and Rhesus statuses were significantly associated with anti-PRP titre. However, multivariate analysis revealed that age between 6-11 months (AOR=3.12,95%CI=1.15-8.50), households with less than three under-fives (AOR=2.33,95%CI=1.14-4.78), middle socioeconomic class (AOR=3.15,95%CI=1.42-6.98), wasting (AOR=2.27,95%CI=1.23-4.22) and Measles/Yellow fever vaccination (AOR=2.90,95%CI=1.38-6.07) were significantly correlated with protective anti-PRP titres. Conclusion: Results indicate that the family and socioeconomic milieu influence anti-PRP titre, and Measles/Yellow fever vaccines may have a beneficial non-specific effect on HCV-induced seroprotection in Nigerian children.

Quantitative assessment of umbilical cord care practices amongst mothers in Jos, Plateau State, Nigeria.

Introduction: A newly cut neonatal umbilical stump is a potential portal of pathogen entry leading to omphalitis. Neonatal sepsis can complicate omphalitis, but good cord care practices can reduce this risk. Objective: The objective of this study was to assess umbilical cord care practices in tertiary-, secondary- and primary-level healthcare facilities in Jos, Nigeria. Methods: A multi-centre, cross-sectional study of 284 mothers of infants aged 3-6 weeks old attending immunisation clinics in the three-level healthcare facilities using multistage sampling technique between April and September 2019. Data were analysed using SPSS version 23.0. Pearson's Chi-squared test was used to compare categorical variables. Adjusted odds ratios (AORs) and 95% confidence interval (CI) were used as point and interval estimates, respectively. P < 0.05 was adjudged to be statistically significant. Results: The mean age of the mothers and infants was 25 ± 6 years and 5 ± 1 week, respectively. Only 2.2% of mothers used chlorhexidine (CHX) gel for cord care. Mothers showed good knowledge but poor practice of cord care. A significant positive relationship was observed between quality of cord care practices and level of healthcare facility (χ2 = 15.213; df = 2; P < 0.001). Good cord care practices were predicted by mothers' age 30-46 (AOR = 3.6; CI: 1.4-9.1) and good knowledge of cord care (AOR = 4.7; 95% CI: 2.2-9.9). Conclusions: The study has highlighted the good knowledge but poor practices of cord care by mothers and the need to scale up the uptake of CHX gel in Jos. Mother's age and good knowledge of cord care are predictors of good cord care practices.

Analysis of sensorineural hearing loss in patients attending an otolaryngology clinic in North Central Nigeria.

Hearing loss is the third leading cause of years lived with disability. Approximately 1.4 billion people have hearing loss, of which 80% reside in low- and middle-income countries with limited audiology and otolaryngology care available to them. The objective of this study was to estimate period prevalence of hearing loss and audiogram patterns of patients attending an otolaryngology clinic in North Central Nigeria. A 10-year retrospective cohort study was carried out analyzing 1507 patient records of pure tone audiograms of patients at the otolaryngology clinic at Jos University Teaching Hospital, Plateau State, Nigeria. Prevalence of hearing loss of moderate or higher grade increased significantly and steadily after age 60. Compared to other studies, there was a higher prevalence of overall sensorineural hearing loss (24-28% in our study compared to 1.7-8.4% globally) and higher proportions of the flat audiogram configuration among the younger age patients (40% in younger patients compared to 20% in patients older than 60 years). The higher prevalence of the flat audiogram configuration compared to other parts of the world may be suggestive of an etiology specific to this region, such as the endemic Lassa Fever and Lassa virus infection in addition to cytomegalovirus or other viral infections associated with hearing loss.

An assessment of improved outcomes using low-cost bubble CPAP in very low birthweight neonates in a Nigerian tertiary hospital.

Respiratory distress contributes to the high burden of preterm mortality globally. The aim of our study was to evaluate the use of low-cost Bubble Continuous Positive Airway Pressure devices for treating respiratory distress and their outcomes in preterm infants weighing <1500g. Data was extracted from admission records of 211 infants over two distinct 4-year periods before and after introduction of bCPAP. With survival rates of 26.7% and 61.8% in the pre and post bCPAP eras respectively, significantly improved outcomes were found.

Immunization status of children 1-5 years old seen at the Emergency Pediatric Unit of a Teaching Hospital in North-Central Nigeria.

Introduction: Advocacy for immunization has been ongoing in various parts of the world to improve immunization uptake amongst children. Annually within the last decade, immunization has been reported to avert over two million deaths globally. This study determined the current immunization status of children 1-5 years of age, the factors affecting immunization uptake and recommends ways of improving immunization uptake among children presenting at an Emergency Pediatric Unit (EPU). Methods: This was a prospective cross-sectional study conducted from 1st October to 30th November 2019. All eligible children aged 1-5 years old seen within the study period whose mothers/caregivers consented to participate in the study were recruited in the EPU of Jos University Teaching Hospital (JUTH), Plateau State, Nigeria. A systematic sampling technique was employed in the selection of caregiver/mother-child pair while data were obtained using an interviewer-administered questionnaire. Results: A total of 191 (76.4%) children were fully immunized for age. Distance to the health facility, experience of vaccine side effects and health workers' attitude were significantly associated with immunization status. Distance to health facility was an independent predictor of complete immunization while short messaging service (SMS) was the most preferred 190 (76.0%) way suggested to improve immunization uptake. Conclusions: This study has brought to light a suboptimal level of full immunization status for age, which can be improved by targeting homegrown interventions at improving accessibility to the facility and addressing adverse events following immunization promptly.

Epidemiological review of confirmed Lassa fever cases during 2016-2018, in Plateau State, North Central Nigeria.

Lassa fever (LF) is endemic in West Africa and constitutes a significant public health concern due to its potential for epidemics and associated high mortality. The first reported case and management of Lassa fever in Plateau State occurred more than 50 years ago. We set out to undertake a three-year epidemiological review of LF cases in Plateau State, North Central Nigeria. This is a retrospective study of all confirmed LF cases in Plateau State between 2016 and 2018. Plateau state Lassa fever- Line list and patient case records were used to extract relevant data. Lassa PCR was carried out at the NCDC accredited Laboratory network. Data analysis was done using STATA version SE14.1. Forty-four persons (44) had confirmed LF over the examined period, 18 (41%) in 2016, 15 (34%) in 2017 and 11 (25%) in 2018. The mean age was 29.7±14.6 years and 53% were males. Sixty-six percent (66%) of the patients resided in rural areas. It affected all local government areas (LGA) in the state except Pankshin, Jos East and Kanke LGAs. Twenty-five percent (25%) of the cases occurred among underprivileged communities of Jos North and another 25% in rural dwellers of Langtang North. Fifty-nine percent (59%) of cases occurred during the 1st quarter, 27% the 2nd quarter and 18% the 3rd quarter of the year. The case fatality rate was 57%. LF is endemic in Plateau State. Prevention strategies must be sustained year round and target the youth, urban and rural underprivileged communities. There is also need for case management improvement to reduce mortality.

Maternal Instruction About Jaundice and the Incidence of Acute Bilirubin Encephalopathy in Nigeria.

OBJECTIVE: To evaluate whether teaching mothers about neonatal jaundice will decrease the incidence of acute bilirubin encephalopathy among infants admitted for jaundice. STUDY DESIGN: This was a multicenter, before-after and cross-sectional study. Baseline incidences of encephalopathy were obtained at 4 collaborating medical centers between January 2014 and May 2015 (Phase 1). Structured jaundice instruction was then offered (May to November 2015; Phase 2) in antenatal clinics and postpartum. Descriptive statistics and logistic regression models compared 3 groups: 843 Phase 1 controls, 338 Phase 2 infants whose mothers received both antenatal and postnatal instruction (group A), and 215 Phase 2 infants whose mothers received no instruction (group B) either because the program was not offered to them or by choice. RESULTS: Acute bilirubin encephalopathy occurred in 147 of 843 (17%) Phase 1 and 85 of 659 (13%) Phase 2 admissions, which included 63 of 215 (29%) group B and 5 of 338 (1.5%) group A infants. OR for having acute bilirubin encephalopathy, comparing group A and group B infants adjusted for confounding risk factors, was 0.12 (95% CI 0.03-0.60). Delayed care-seeking (defined as an admission total bilirubin ≥18 mg/dL at age ≥48 hours) was the strongest single predictor of acute bilirubin encephalopathy (OR 11.4; 6.6-19.5). Instruction decreased delay from 49% to 17%. Other major risk factors were home births (OR 2.67; 1.69-4.22) and hemolytic disease (hematocrit ≤35% plus bilirubin ≥20 mg/dL) (OR 3.03; 1.77-5.18). The greater rate of acute bilirubin encephalopathy with home vs hospital birth disappeared if mothers received jaundice instruction. CONCLUSIONS: Providing information about jaundice to mothers was associated with a reduction in the incidence of bilirubin encephalopathy per hospital admission.

Head Circumference of Babies at Birth in Nigeria.

BACKGROUND AND OBJECTIVES: Measuring head circumference (HC) of newborns is an important tool for evaluating intra-uterine brain development. HC reference charts currently in use in Nigeria are not representative of the local population. We thus present locally derived HC reference data for Nigerian infants at birth. SUBJECTS AND METHODS: We reviewed birth records of all infants at the Jos University Teaching Hospital (JUTH) over a 10 year period from January 2006. JUTH is a tertiary care center offering obstetric services to a large population of women in Jos and its environs. All births with gestational age between 28 and 42 weeks were included in the study. STATA version 14 was used to calculate gestational age associated HC percentile measurements. RESULTS: We included 18 282 babies to generate the reference values. The mean HC value was 34.4 ± 2.1 cm (M = 34.6 ± 2.16 cm, F = 34.1 ± 2.02 cm, p < 0.001). Our HC reference values significantly differ from the USA and INTERGROWTH-21 charts currently in use in our country. Mean HC was higher in male infants compared with female infants. This difference was uniformly so across all gestational age groups. CONCLUSIONS: The use of our locally derived HC reference values could be more appropriate in defining normal head growth in Nigerian infant populations thereby improving newborn care.

Pathogenesis, diagnostic challenges and treatment of zika virus disease in resource-limited settings.

The association of Zika virus (ZIKV) infection with congenital malformation and neurological sequelae has brought significant global concern. Consequently, the World Health Organization (WHO) declared it "a public health emergency of International concern" on 1 February, 2016. A critical review of its pathogenesis would lead to a better understanding of the clinical features and the neurological complications. This review is based on literature search in PubMed/Medline, Google Scholar and the WHO, http://www.who.int. This include all relevant articles written in English published through June 2018, with subject heading and keywords such as Zika, ZIKV, Zika pathogenesis, diagnosis of Zika, Zika Nigeria, Zika Africa and Zika resource-limited settings. Following ZIKV infection, viraemia ensues targeting primarily the monocytes for both the Asian and African strains. ZIKV infection by an African strain appears to be more pathogenic, in early pregnancy tends to result in spontaneous abortion. Whereas an Asian strain tends to be less pathogenic and more chronic, this allows the pregnancy to continue, ultimately resulting in congenital malformations. There is no routine laboratory diagnosis of ZIKV infection in resource-constrained countries. Serologic tests should be interpreted with caution since there can be cross-reactivity with other flaviviruses, especially in Africa where the burden of infection with flaviviruses is comparatively high. There is a paucity of well-equipped laboratories for comprehensive ZIKV diagnosis. It is imperative to strengthen the health systems, improve health workforce and diagnostic capacity of such settings.

Low Zika virus seroprevalence among pregnant women in North Central Nigeria, 2016.

BACKGROUND: Zika virus (ZIKV) has been known for decades in Africa but contemporary data is lacking at large. OBJECTIVES: To describe the seroepidemiology of ZIKV in North Central Nigeria. STUDY DESIGN: We performed a cross-sectional study at six health care facilities in North Central Nigeria from January to December 2016. Detection of ZIKV antibodies was done using an anti-ZIKV recombinant non-structural protein 1 (NS1)-based ELISA. A colorimetric assay to detect ZIKV neutralizing antibodies was used on ELISA reactive and randomly selected ELISA non-reactive samples. ZIKV real-time RT-PCR was done on a subset of samples. RESULTS: A total of 468 individual samples were included with almost 60% from pregnant women. Using NS1-based ELISA, an anti-ZIKV positive rate of 6% for IgM and 4% for IgG was found. Pregnant women showed anti-ZIKV positive rates of 4% for IgM and 3% for IgG. None of the ZIKV antibody positive samples tested ZIKV RT-PCR positive. An association with male sex was found for anti-ZIKV IgG ELISA positivity (prevalence ratio 3.49; 95% confidence interval: 1.48-8.25; p = .004). No association with pregnancy, yellow fever vaccination or malaria was found for anti-ZIKV IgM or IgG positivity. ZIKV neutralizing antibodies were detected in 17/18 (94%) anti-ZIKV NS1 positive/borderline samples and in one sample without detectable ZIKV NS1 antibodies. Partial ZIKV E gene sequence was retrieved in one sample without ZIKV antibodies, which clustered within the West African ZIKV lineage. CONCLUSIONS: Our results show a largely ZIKV immunologically naïve population and reinforce the importance of ZIKV surveillance in Africa.

Prevalence and correlates of stunting among the school-age population in North-Central Nigeria.

INTRODUCTION: Stunting remains a huge public health concern among developing Nations. However, the burden of this problem among the school-age population appears to have been eclipsed by most nutritional surveys that focus more on the under-fives. This study aimed to demonstrate the prevalence, and identify socio-demographic factors that are associated with stunting among the school-age children in North central Nigeria. METHODS: This was a descriptive cross-sectional study that involved 450 pupils, aged 6-12 years from 10 randomly selected primary schools in Jos, Plateau state. Anthropometric indices were measured using standard techniques and the Height-for-age z-scores were generated using the WHO Anthroplus software. Socio-demographic details were obtained using semi-structured questionnaires. Data were analysed using EPI infoTM statistical software 7.1.5.2. RESULTS: The mean age of the subjects was 9.3 ± 1.8 years and the male to female ratio was 1:1.1. The prevalence of stunting was 10.5%. The prevalence of stunting was significantly higher among pupils that attended public schools (p<0.0001), those whose mothers had less than secondary level of education (p=0.0427), those between the ages of 10-12 years (p<0.0001), those from the lower socio-economic class (p=0.0021), and those whose family sizes were larger than six family members (p=0.0063). CONCLUSION: The substantial burden of stunting among the school age population has significant correlation with certain socio-demographic factors. Addressing these factors by alleviating poverty, promoting maternal literacy and encouraging family planning may, perhaps, lessen the burden of stunting among the school-age group in Northern Nigeria.

Factors influencing irradiance of locally fabricated phototherapy devices in Jos, north-central Nigeria.

Locally fabricated phototherapy devices (LFPDs) are widely used in Nigeria for the treatment of neonatal jaundice. Ours was a cross-sectional observational study of all LFPDs in major hospitals in Jos between January and March 2015. We evaluated a total of 24 LFPDs. The irradiance at the level of the baby was in the range of 2-23.9 µW/cm2/nm. Fourteen devices had the recommended irradiance of ≥10 µW/cm2/nm and none had irradiance in the intensive range. Decreasing distance from the baby, presence of reflectors and increasing number of flourecent tubes significantly contributed to higher irradiance. A combination of six tubes, presence of reflectors and a distance of 10 cm from the baby produced a mean irradiance of 23.40 µW/cm2/nm. The irradiance of LFPDs varies widely and can be improved by simple modifications.

Factors associated with antiretroviral treatment interruption in human immunodeficiency virus (HIV)-1-infected children attending the Jos University Teaching Hospital, Jos, Nigeria.

BACKGROUND: Interrupting anti-retroviral therapy (ART) for any number of reasons is an indication of a compromised adherence to ART. Several factors, including the pill burden from other drugs used in treating co-infections in children with human immunodeficiency virus (HIV), may influence ART adherence. The aim of this study was to identify the factors associated with ART interruption in HIV-1-infected children. MATERIALS AND METHODS: A retrospective cohort study analysing data on 580 children consecutively enrolled on ART between February 2006 and December 2010 at the paediatric HIV clinic of Jos University Teaching Hospital (JUTH), Jos. Subjects were children aged 2 months - 15 years diagnosed with HIV-1 infection and on first-line ART. Cotrimoxazole prophylaxis was usually commenced at diagnosis while awaiting ART commencement. Children diagnosed with tuberculosis (TB) were also placed on multiple individual anti-TB drugs. STATISTICAL ANALYSIS USED: A comparison of the data on children with and without ART interruption was made. Variables associated with ART interruption in a univariate analysis were fit in a multivariate logistic model to determine the factors that were associated with ART interruption. RESULTS: Children on anti-TB drugs were twice more likely to interrupt ART compared to those who were not, (adjusted odds ratio, AOR = 1.84 (1.03-3.28); P = 0.04). But children on cotrimoxazole prophylaxis had a 57% reduction in the odds of interrupting ART compared to those who were not, (AOR = 0.43 (0.20-0.93); P = 0.03). CONCLUSION: Children on ART and also taking multiple individual anti-TB drugs should be monitored closely for ART adherence. Cotrimoxazole prophylaxis should be encouraged in children diagnosed with HIV while awaiting ART commencement as this may prime them for a better ART adherence.

Immunogenicity and safety of the candidate RTS,S/AS01 vaccine in young Nigerian children: a randomized, double-blind, lot-to-lot consistency trial.

BACKGROUND: For regulatory approval, consistency in manufacturing of vaccine lots is expected to be demonstrated in confirmatory immunogenicity studies using two-sided equivalence trials. This randomized, double-blind study (NCT01323972) assessed consistency of three RTS,S/AS01 malaria vaccine batches formulated from commercial-scale purified antigen bulk lots in terms of anti-CS-responses induced. METHODS: Healthy children aged 5-17 months were randomized (1:1:1:1) to receive RTS,S/AS01 at 0-1-2 months from one of three commercial-scale purified antigen bulk lots (1600 litres-fermentation scale; commercial-scale lots), or a comparator vaccine batch made from pilot-scale purified antigen bulk lot (20 litres-fermentation scale; pilot-scale lot). The co-primary objectives were to first demonstrate consistency of antibody responses against circumsporozoite (CS) protein at one month post-dose 3 for the three commercial-scale lots and second demonstrate non-inferiority of anti-CS antibody responses at one month post-dose 3 for the commercial-scale lots compared to the pilot-scale lot. Safety and reactogenicity were evaluated as secondary endpoints. RESULTS: One month post-dose-3, anti-CS antibody geometric mean titres (GMT) for the 3 commercial scale lots were 319.6 EU/ml (95% confidence interval (CI): 268.9-379.8), 241.4 EU/ml (207.6-280.7), and 302.3 EU/ml (259.4-352.3). Consistency for the RTS,S/AS01 commercial-scale lots was demonstrated as the two-sided 95% CI of the anti-CS antibody GMT ratio between each pair of lots was within the range of 0.5-2.0. GMT of the pooled commercial-scale lots (285.8 EU/ml (260.7-313.3)) was non-inferior to the pilot-scale lot (271.7 EU/ml (228.5-323.1)). Each RTS,S/AS01 lot had an acceptable tolerability profile, with infrequent reports of grade 3 solicited symptoms. No safety signals were identified and no serious adverse events were considered related to vaccination. CONCLUSIONS: RTS,S/AS01 lots formulated from commercial-scale purified antigen bulk batches induced a consistent anti-CS antibody response, and the anti-CS GMT of pooled commercial-scale lots was non-inferior to that of a lot formulated from a pilot-scale antigen bulk batch.