Background: Reducing the risks of vaccine-derived polioviruses and vaccine-associated paralytic poliomyelitis motivated the development of novel types 1 and 3 oral poliovirus vaccines (nOPV1 and nOPV3, respectively), designed to have similar safety and immunogenicity and improved genetic stability (to reduce risk of reversion to neurovirulence) relative to types 1 or 3 Sabin-strain OPVs. We aimed to assess the safety and immunogenicity of nOPV1 and nOPV3 in healthy adults.
Methods: We did a first-in-human, observer-masked, multicentre, phase 1 randomised controlled trial in healthy adults at four centres in the USA.
Vaccine
August 2025
Unlabelled: Continuous boosting with the original vaccines based on the Ancestral (Wuhan hu-1) strain to maintain immunity has not been sufficient to detain the emergence and rapid dissemination of viral variants. This study was to evaluate the immune responses and safety of a heterologous boost with bivalent Original/Omicron BA.4-5 vaccine mRNA vaccine given after at least 12 months to those who had been primed with NDV-HXP-S COVID -19 vaccine (an inactivated recombinant Newcastle disease virus vaccine).
View Article and Find Full Text PDFBackground: RTS,S/AS01 vaccine efficacy (VE) was previously shown as lower in African adults than in malaria-naïve US adults, potentially due to concurrent Plasmodium falciparum (Pf) infections. We investigated whether treatment of infection prior to vaccination would lead to improved VE and immunogenicity.
Methods: A Phase 2b study in Kenyan adults evaluated the efficacy of RTS,S/AS01E in conjunction with antimalarial chemopreventive drugs.
Malar J
May 2025
Background: New malaria control tools are needed to prevent the transmission of parasites from the host to the mosquito vector and vice versa. The infectiousness of Plasmodium falciparum gametocytes obtained from individuals to laboratory-reared mosquitoes should be quantified to employ easily applicable assays for evaluating transmission-blocking interventions. This study aimed to establish the relationship between parasite transmission from humans to mosquitoes both within a person and across persons by assessing the variation in the proportion of infected mosquitoes with at least one oocyst (oocyst prevalence) in a direct membrane feeding assay (DMFA) and direct skin landing feeding assay (DSFA) performed at two consecutive time points in the same human subject with P.
View Article and Find Full Text PDFBackground: Human papillomavirus (HPV) vaccines have been available for nearly 20 years. However, the overall coverage of girls aged 15 years and younger is low, especially in low-resource settings, where the burden of cervical cancer is highest. Increasing access and facilitating implementation of HPV vaccination will contribute to cervical cancer elimination efforts.
View Article and Find Full Text PDFVaccine
April 2025
COVID-19 continues to be a health issue, mainly due to virus circulation and the emergence of new variants of concern and interest. This is a single-center, randomized, double-blind, active-controlled dose-escalating phase I clinical trial to evaluate the immunogenicity and safety of NDV-HXP-S (1 μg, 3 μg, and 10 μg), an inactivated COVID-19 vectored-vaccine virus using the Newcastle Disease Virus (NDV) expressing stabilized pre-fusion S protein from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Healthy SARS-CoV-2-naïve participants aged 18 to 59 years were randomized in a 3:3:3:1 ratio to receive two equal shots of 1 μg, 3 μg or 10 μg of NDV-HXP-S formulations or placebo/CoronaVac intramuscular 28 days apart, respectively.
View Article and Find Full Text PDFProduction of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and lower-middle-income countries is needed. NDV-HXP-S is an inactivated egg-based recombinant Newcastle disease virus vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A public sector manufacturer in Vietnam assessed the immunogenicity of NDV-HXP-S (COVIVAC) relative to an authorized vaccine.
View Article and Find Full Text PDFBACKGROUNDThe mechanism(s) responsible for the efficacy of WHO-recommended malaria vaccine RTS,S/AS01 are not completely understood. We previously identified RTS,S vaccine-induced Plasmodium falciparum circumsporozoite protein-specific (PfCSP-specific) antibody measures associated with protection from controlled human malaria infection (CHMI). Here, we tested the protection-predicting capability of these measures in independent CHMI studies.
View Article and Find Full Text PDFInt J Environ Res Public Health
January 2024
Urban population growth in Nigeria may exceed the availability of affordable housing and basic services, resulting in living conditions conducive to vector breeding and heterogeneous malaria transmission. Understanding the link between community-level factors and urban malaria transmission informs targeted interventions. We analyzed Demographic and Health Survey Program cluster-level data, alongside geospatial covariates, to describe variations in malaria prevalence in children under 5 years of age.
View Article and Find Full Text PDFBackground: The only licensed malaria vaccine, RTS,S/AS01 , confers moderate protection against symptomatic disease. Because many malaria infections are asymptomatic, we conducted a large-scale longitudinal parasite genotyping study of samples from a clinical trial exploring how vaccine dosing regimen affects vaccine efficacy (VE).
Methods: 1,500 children aged 5-17 months were randomized to receive four different RTS,S/AS01 regimens or a rabies control vaccine in a phase 2b clinical trial in Ghana and Kenya.
Background: Inactivated trivalent poliovirus vaccine (IPV) induces humoral immunity, which protects against paralytic poliomyelitis but does not induce sufficient mucosal immunity to block intestinal infection. We assessed the intestinal immunity in healthy adults in Belgium conferred by a co-formulation of IPV with the mucosal adjuvant double mutant Labile Toxin (dmLT) derived from Escherichia coli.
Methods: Healthy fully IPV-vaccinated 18-45-year-olds were randomly allocated to three groups: on Day 1 two groups received one full dose of IPV (n = 30) or IPV + dmLT (n = 30) in a blinded manner, and the third received an open-label dose of bivalent live oral polio vaccine (bOPV types 1 and 3, n = 20).
Background: Rotavirus infection remains an important cause of morbidity and mortality in children. The introduction of vaccination programs in more than 100 countries has contributed to a decrease in hospitalizations and mortality. This study investigates the epidemiological impact of the rotavirus vaccine ROTAVAC® in the Palestinian Territories, the first country to switch from ROTARIX® to this new vaccine.
View Article and Find Full Text PDFProduction of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based Newcastle disease virus (NDV) vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Wuhan-Hu-1. The spike protein was stabilized and incorporated into NDV virions by removing the polybasic furin cleavage site, introducing the transmembrane domain and cytoplasmic tail of the fusion protein of NDV, and introducing six prolines for stabilization in the prefusion state.
View Article and Find Full Text PDFEClinicalMedicine
March 2022
Background: Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based recombinant Newcastle disease virus vaccine expressing the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It's being developed by public sector manufacturers in Thailand, Vietnam, and Brazil; herein are initial results from Thailand.
View Article and Find Full Text PDFNovel oral poliovirus vaccine type 2 (nOPV2) is being developed to reduce the rare occurrence of disease and outbreaks associated with the genetic instability of the Sabin vaccine strains. Children aged 1 to 5 years were enrolled in two related clinical studies to assess safety, immunogenicity, shedding rates and properties of the shed virus following vaccination with nOPV2 (two candidates) versus traditional Sabin OPV type 2 (mOPV2). The anticipated pattern of reversion and increased virulence was observed for shed Sabin-2 virus, as assessed using a mouse model of poliovirus neurovirulence.
View Article and Find Full Text PDFPLoS Negl Trop Dis
November 2021
Cholera remains a major cause of infectious diarrhea globally. Despite the increased availability of cholera vaccines, there is still an urgent need for other effective interventions to reduce morbidity and mortality. Furthermore, increased prevalence of antibiotic-resistant Vibrio cholerae threatens the use of many drugs commonly used to treat cholera.
View Article and Find Full Text PDFmedRxiv
September 2021
Background: Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based Newcastle disease virus vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It's being developed in Thailand, Vietnam, and Brazil; herein are initial results from Thailand.
View Article and Find Full Text PDFSabin-strain oral polio vaccines (OPV) can, in rare instances, cause disease in recipients and susceptible contacts or evolve to become circulating vaccine-derived strains with the potential to cause outbreaks. Two novel type 2 OPV (nOPV2) candidates were designed to stabilize the genome against the rapid reversion that is observed following vaccination with Sabin OPV type 2 (mOPV2). Next-generation sequencing and a modified transgenic mouse neurovirulence test were applied to shed nOPV2 viruses from phase 1 and 2 studies and shed mOPV2 from a phase 4 study.
View Article and Find Full Text PDFEnvironmental enteric dysfunction (EED) is an intestinal disorder common among children in low-resource settings and is associated with increased risk of growth stunting, cognitive deficits, and reduced oral vaccine immunogenicity. The Micronutrient and EED Assessment Tool (MEEDAT) is a multiplexed immunoassay that measures biomarkers previously associated with child growth faltering and/or oral vaccine immunogenicity: intestinal fatty acid-binding protein (I-FABP), soluble CD14 (sCD14), insulin-like growth factor 1 (IGF-1), and fibroblast growth factor 21 (FGF21). MEEDAT also measures systemic inflammation (α1-acid glycoprotein, C-reactive protein), ferritin, soluble transferrin receptor, retinol binding protein 4, thyroglobulin, and Plasmodium falciparum antigenemia (histidine-rich protein 2).
View Article and Find Full Text PDFBackground: In 2016, the Zambian National Malaria Elimination Centre started programmatic mass drug administration (pMDA) campaigns with dihydroartemisinin-piperaquine as a malaria elimination tool in Southern Province. Two rounds were administered, 2 months apart (coverage 70% and 57%, respectively). We evaluated the impact of 1 year of pMDA on malaria incidence using routine data.
View Article and Find Full Text PDFBackground: Previous studies show a positive association between household wealth and overweight in sub-Saharan African (SSA) countries; however, the manner in which this relationship differs in the presence of educational attainment has not been well-established. This study examined the multiplicative effect modification of educational attainment on the association between middle-income and rich household wealth and overweight status among adult females in 22 SSA countries. We hypothesized that household wealth was associated with a greater likelihood of being overweight among middle income and rich women with lower levels of educational attainment compared to those with higher levels of educational attainment.
View Article and Find Full Text PDFNational vaccination coverage estimates from household surveys are widely used in monitoring and planning of immunization programs. In Nigeria, survey-reported national coverage estimates have shown large fluctuations in the past few years. In this paper, we examine the impact of state-level survey weighting on Nigeria's national vaccination coverage estimation.
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