"RTS,S"

Genotypic analysis of RTS,S/AS01(E) malaria vaccine efficacy against parasite infection as a function of dosage regimen and baseline malaria infection status in children aged 5-17 months in Ghana and Kenya: a longitudinal phase 2b randomised controlled t The first 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. Between Sept 28, 2017, and Sept 25, 2018, 1500 children aged 5-17 months were randomly assigned (1:1:1:1:1) to receive four different RTS,S/AS01 regimens or a rabies control vaccine in a phase 2b open-label clinical trial in Ghana

Feasibility, safety, and impact of the RTS,S/AS01(E) malaria vaccine when implemented through national immunisation programmes: evaluation of cluster-randomised introduction of the vaccine in Ghana, Kenya, and Malawi. The RTS,S/AS01 malaria vaccine (RTS,S) was introduced by national immunisation programmes in Ghana, Kenya, and Malawi in 2019 in large-scale pilot schemes. We aimed to address questions about feasibility and impact, and to assess safety signals that had been observed in the phase 3 trial that included an excess of meningitis and cerebral malaria cases in RTS,S recipients, and the possibility of an excess of deaths among girls who received RTS,S than in controls, to inform decisions about wider use. In this prospective evaluation, 158 geographical clusters (66 districts in Ghana

Implementation strategies for the introduction of the RTS,S/AS01 (RTS,S) malaria vaccine in countries with areas of highly seasonal transmission: workshop meeting report. A workshop on implementation strategies for the introduction of the RTS,S/AS01 (RTS,S) malaria vaccine in countries with areas of highly seasonal transmission, was held as a hybrid meeting in Dakar, Senegal, and online, 23-25 January 2023. Delegates from Expanded Programmes on Immunization (EPI) and National Malaria Control Programmes (NMCPs) from 13 African countries, and representatives from key stakeholders participated. RTS,S is the first malaria vaccine to be recommended by the World Health Organization (WHO). The recommendation followed pilot implementation of the vaccine in Ghana, Kenya and Malawi, which showed

Correlations between three ELISA protocols measurements of RTS,S/AS01-induced anti-CSP IgG antibodies. RTS,S/AS01 induced anti-circumsporozoite protein (CSP) IgG antibodies are associated with the vaccine efficacy. There is currently no international standardisation of the assays used in the measurement of anti-CSP IgG antibody concentrations for use in evaluations of the vaccine's immunogenicity and/or efficacy. Here, we compared the levels of RTS,S/AS01 induced anti-CSP IgG antibodies measured using three different enzyme-Linked ImmunoSorbent Assays (ELISA). 196 plasma samples were randomly selected from the 447 samples collected during the RTS,S/AS01 phase IIb trial in 2007 from Kenyan children aged between 5-17 months. The vaccine-induced anti-CSP IgG antibodies were then measured

A phase IIa, randomized, double-blind, safety, immunogenicity and efficacy trial of Plasmodium falciparum vaccine antigens merozoite surface protein 1 and RTS,S formulated with AS02 adjuvant in healthy, malaria-naïve adults. To improve the efficacy of Plasmodium falciparum malaria vaccine RTS,S/AS02, we conducted a study in 2001 in healthy, malaria-naïve adults administered RTS,S/AS02 in combination with FMP1, a recombinant merozoite surface-protein-1, C-terminal 42kD fragment. A double-blind Phase I/IIa study randomized N = 60 subjects 1:1:1:1 to one of four groups, N = 15/group, to evaluate safety, immunogenicity, and efficacy of intra-deltoid half-doses of RTS,S/AS02 and FMP1/AS02 administered in the contralateral (RTS,S + FMP1-separate) or same (RTS,S + FMP1-same) sites, or FMP1/AS02

Could less be more? Accounting for fractional-dose regimens and different number of vaccine doses when measuring the impact of the RTS, S/AS01E malaria vaccine. The RTS, S/AS01E malaria vaccine (RTS, S) is recommended for children in moderate-to-high Plasmodium falciparum malaria transmission areas. This phase 2b trial (NCT03276962) evaluates RTS, S fractional- and full-dose regimens in Ghana and Kenya. 1500 children aged 5-17 months were randomised (1:1:1:1:1) to receive RTS, S or rabies control vaccine. RTS, S groups received two full RTS, S doses at month (M)0/M1 followed by either full (groups R012-20, R012-14-26) or fractional (1/5) doses (groups Fx012-14-26, Fx017-20-32). At M32 post-first dose, vaccine efficacy (VE) against clinical malaria (all episodes) ranged from 38% (R012-20; 95%CI

Integration of the RTS,S/AS01 malaria vaccine into the Essential Programme on Immunisation in western Kenya: a qualitative longitudinal study from the health system perspective. Malaria accounts for over half a million child deaths annually. WHO recommends RTS,S/AS01 to prevent malaria in children living in moderate-to-high malaria transmission regions. We conducted a qualitative longitudinal providers highlighted limitations in RTS,S/AS01 integration into routine immunisation services due to the concurrent pilot evaluation and temporary adaptations for health reporting. Initial challenges related to the complexity of the four-dose schedule (up to 24-months); however, self-efficacy increased over time as the health-care providers gained experience in vaccine delivery. Low uptake of the fourth

Antibody mechanisms of protection against malaria in RTS,S-vaccinated children: a post-hoc serological analysis of phase 2 trial. The RTS,S malaria vaccine is currently recommended for children aged 5-6 months in regions with moderate-to-high Plasmodium falciparum transmission. However, vaccination only confers 55% efficacy over 12 months and wanes within 18 months. The immunological mechanisms of RTS,S-mediated immunity are poorly understood; therefore, we aimed to identify antibody response types associated with protection against malaria in children vaccinated with RTS,S. In this post-hoc analysis, we evaluated antibody responses in 737 children aged 1-4 years vaccinated with RTS,S in a phase 2b clinical trial conducted in Mozambique in 2003. We evaluated all available samples collected

Identification of RTS,S/AS01 vaccine-induced humoral biomarkers predictive of protection against controlled human malaria infection.

The impact of the RTS,S malaria vaccine on uncomplicated malaria: evidence from the phase IV study districts, Upper East Region, Ghana, 2020-2022. The RTS,S malaria vaccine has been prequalified for use in endemic settings prioritizing areas with moderate to high disease transmission. The impact of a vaccine at the population level may differ from observations during clinical trial due to programmatic, and individual-related factors, among others. The objective of this study was to assess the impact of the RTS,S malaria vaccine on uncomplicated malaria among children aged 12-59 months in the Phase IV study districts, Upper East Region, Ghana. A retrospective study was conducted using routine malaria surveillance data for the period 2020-2022. The burden of uncomplicated malaria was compared

An assessment of Ghana's pilot of the RTS,S malaria vaccine implementation programme; 2019-2021: a retrospective study. In May 2019, Ghana piloted the introduction of RTS,S malaria vaccine into routine immunization in 42 districts of seven of the 16 regions. The RTS,S malaria vaccine implementation programme (MVIP) post-introduction evaluation (PIE) conducted in Ghana, assessed the immunization . The lessons from the MVIP may be relevant to areas introducing malaria vaccine irrespective of the product type-RTS,S or R21.

Influence of trust on the acceptance of the RTS,S malaria vaccine in the Kassena-Nankana districts of Ghana. Vaccines have increasingly become some of the most effective public health tools for promoting health and reducing the burden of infectious diseases. The availability of a malaria vaccine for routine use will be a major milestone, nonetheless, trust by the public for the vaccine could of trust on vaccine acceptance while QSR NVivo 12 software was used to code the qualitative data to aid the thematic analysis. The results revealed that the level of knowledge of the RTS,S vaccine among participants was high. About 95.4% of the mothers had good knowledge of the malaria vaccine and more than half 61.2% of them got information about the vaccine from the health facility. The level of trust

The effect of Plasmodium falciparum exposure and maternal anti-circumsporozoite protein antibodies on responses to RTS,S/AS01(E) vaccination in infants and children: an ancillary observational immunological study to a phase 3, randomised clinical trial. The RTS,S/AS01 malaria vaccine showed lower antibody response and protective efficacy in infants aged 6-12 weeks compared with children aged 5 -17 months (for whom this vaccine is recommended). We aimed to study the effect of previous Plasmodium falciparum exposure on the antibody responses to RTS,S/AS01 vaccination in infants and children, and the mediating effect of baseline (including maternal) anti-circumsporozoite protein (CSP) antibodies. In this observational study, we included children and infants from six African countries

RTS,S/AS01E malaria vaccine (Mosquirix). Children living in malaria-endemic regions: little efficacy, poorly documented harms Prescrire IN ENGLISH - Spotlight ''RTS,S/AS01E malaria vaccine (Mosquirix°). Children living in malaria-endemic regions: little efficacy, poorly documented harms'', 1 January 2017 {1}##LOC[OK]## {1} ##LOC[OK]## ##LOC[Cancel]## {1}##LOC[OK]####LOC[Cancel]## Register online International * Testimonials * Prescrire events * A global network Offers * Subscribe now * Solidarity Subscription Rate * Subscribers: register online * Prescrire's other products * Free Special Edition * Sign up to receive the newsletter english.prescrire.org > Spotlight > 100 most recent > RTS,S/AS01E malaria vaccine (Mosquirix°). Children living in malaria-endemic regions: little

RTS,S/AS01 malaria vaccine-proven safe and effective? In October, 2021, WHO recommended that the RTS,S malaria vaccine, with its strong safety profile and high impact, be provided to children from age 5 months in regions with moderate to high Plasmodium falciparum malaria transmission. The evidence base included phase 3 trials in seven African countries and an ongoing malaria vaccine

RTS,S/AS01 malaria vaccine pilot implementation in western Kenya: a qualitative longitudinal study to understand immunisation barriers and optimise uptake. Malaria is a significant public health threat in sub-Saharan Africa, particularly among children. The RTS,S/AS01 malaria vaccine reduces the risk and severity of malaria in children. RTS,S/AS01 was piloted in three African countries, Ghana , Kenya and Malawi, to assess safety, feasibility and cost-effectiveness in real-world settings. A qualitative longitudinal study was conducted as part of the feasibility assessment. This analysis explores RTS,S/AS01 vaccination barriers and identifies potential motivators among caregivers in three sub-counties in western Kenya. A cohort of 63 caregivers with a malaria vaccine eligible child

RTS,S/AS01(E) vaccine defaults in Ghana: a qualitative exploration of the perspectives of defaulters and frontline health service providers. While Ghana has a good track record in the Expanded Programme on Immunization, there are substantial challenges with regards to subsequent vaccinations, particularly after the first year of life of the child. Given that the last dose of the RTS, S/AS01 vaccine against malaria is administered at 24 months, there is a high likelihood of default. Hence, it is imperative to understand the dynamics and reasons for the defaults to enable the development of effective implementation strategies. This study explored why caregivers default on the RTS, S/AS01 vaccine from the perspective of health service providers and caregivers. This study employed

Background malaria incidence and parasitemia during the three-dose RTS,S/AS01 vaccination series do not reduce magnitude of antibody response nor efficacy against the first case of malaria. RTS,S/AS01 has been recommended by WHO for widespread implementation in medium to high malaria transmission settings. Previous analyses have noted lower vaccine efficacies in higher transmission settings from three study areas (Kintampo, Ghana; Lilongwe, Malawi; Lambaréné, Gabon) from the 2009-2014 phase III trial (NCT00866619). Our key exposures are parasitemia during the vaccination series and background malaria incidence. We calculate vaccine efficacy (one minus hazard ratio) using a cox-proportional hazards model and allowing for the time-varying effect of RTS,S/AS01. We find that antibody

Baseline malaria infection status and RTS,S/AS01E malaria vaccine efficacy. 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 ). 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. We evaluated the time to the first new genotypically detected infection and the total number of new infections during two follow-up periods in over 36K participant specimens. We performed a post hoc analysis of VE based on malaria

Seasonal vaccination with RTS,S/AS01(E) vaccine with or without seasonal malaria chemoprevention in children up to the age of 5 years in Burkina Faso and Mali: a double-blind, randomised, controlled, phase 3 trial. Seasonal vaccination with the RTS,S/AS01 vaccine combined with seasonal malaria chemoprevention (SMC) prevented malaria in young children more effectively than either intervention who had been enrolled in the initial 3-year trial when aged 5-17 months were initially randomly assigned individually to receive SMC with sulphadoxine-pyrimethamine and amodiaquine plus control vaccines, RTS,S/AS01 plus placebo SMC, or SMC plus RTS,S/AS01. They continued to receive the same interventions until the age of 5 years. The primary trial endpoint was the incidence of clinical malaria over