Correction: Costs of continuing RTS,S/ASO1E malaria vaccination in the three malaria vaccine pilot implementation countries.
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ABSTRACT:
SUBMITTER: Baral R
PROVIDER: S-EPMC8061918 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThe RTS,S/ASO1E malaria vaccine is being piloted in three countries-Ghana, Kenya, and Malawi-as part of a coordinated evaluation led by the World Health Organization, with support from global partners. This study estimates the costs of continuing malaria vaccination upon completion of the pilot evaluation to inform decision-making and planning around potential further use of the vaccine in pilot areas.MethodsWe used an activity-based costing approach to estimate the incremental costs of continuing to deliver four doses of RTS,S/ASO1E through the existing Expanded Program on Immunization platform, from each government's perspective. The RTS,S/ASO1E pilot introduction plans were reviewed and adapted to identify activities for costing. Key informant interviews with representatives from Ministries of Health (MOH) were conducted to inform the activities, resource requirements, and assumptions that, in turn, inform the analysis. Both financial and economic costs per dose, cost of delivery per dose, and cost per fully vaccinated child (FVC) are estimated and reported in 2017 USD units.ResultsAt a vaccine price of $5 per dose and assuming the vaccine is donor-funded, our estimated incremental financial costs range from $1.70 (Kenya) to $2.44 (Malawi) per dose, $0.23 (Malawi) to $0.71 (Kenya) per dose delivered (excluding procurement add-on costs), and $11.50 (Ghana) to $13.69 (Malawi) per FVC. Estimates of economic costs per dose are between three and five times higher than financial costs. Variations in activities used for costing, procurement add-on costs, unit costs of per diems, and allowances contributed to differences in cost estimates across countries.ConclusionCost estimates in this analysis are meant to inform country decision-makers as they face the question of whether to continue malaria vaccination, should the intervention receive a positive recommendation for broader use. Additionally, important cost drivers for vaccine delivery are highlighted, some of which might be influenced by global and country-specific financing and existing procurement mechanisms. This analysis also adds to the evidence available on vaccine delivery costs for products delivered outside the standard immunization schedule.
| S-EPMC7799756 | biostudies-literature
Project description:Background. The World Health Organization has recommended pilot implementation of a candidate vaccine against malaria (RTS,S/AS01) in selected sub-Saharan African countries. This exploratory study aimed to estimate the costs of implementing RTS,S in Burkina Faso, Ghana, Kenya, Mozambique, and Tanzania. Methods. Key informants of the expanded program on immunization at all levels in each country were interviewed on the resources required for implementing RTS,S for routine vaccination. Unit prices were derived from the same sources or from international price lists. Incremental costs in 2015 US dollars were aggregated per fully vaccinated child (FVC). It was assumed the four vaccine doses were either all delivered at health facilities or the fourth dose was delivered in an outreach setting. Results. The costs per FVC ranged from US$25 (Burkina Faso) to US$37 (Kenya) assuming a vaccine price of US$5 per dose. Across countries, recurrent costs represented the largest share dominated by vaccines (including wastage) and supply costs. Non-recurrent costs varied substantially across countries, mainly because of differences in needs for hiring personnel, in wages, in cold-room space, and equipment. Recent vaccine introductions in the countries may have had an impact on resource availability for a new vaccine implementation. Delivering the fourth dose in outreach settings raised the costs, mostly fuel, per FVC by less than US$1 regardless of the country. Conclusions. This study provides relevant information for donors and decision makers about the cost of implementing RTS,S. Variations within and across countries are important and the unknown future price per dose and wastage rate for this candidate vaccine adds substantially to the uncertainty about the actual costs of implementation.
| S-EPMC6923697 | biostudies-literature
Project description: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 that introduction of the vaccine was highly effective at scale, and was associated with a 30% reduction in hospital admissions with severe malaria in age groups eligible to have received the vaccine and no evidence of the safety signals that had been observed in the phase 3 trial. Clinical trials in Mali and Burkina Faso, showed that in children receiving Seasonal Malaria Chemoprevention (SMC), providing the vaccine just prior to high transmission seasons, matching the period of highest efficacy to the peak transmission season, resulted in substantial reduction in the incidence of clinical malaria and of severe malaria. While SMC has been successfully scaled-up despite the challenges of delivery, there is no established platform for seasonal vaccine delivery and no real-world experience. The objectives of this workshop were, therefore, to share experiences from countries that have introduced the RTS,S vaccine in routine child vaccination programmes, with SMC-implementing countries as they consider malaria vaccine introduction, and to explore implementation strategies in countries with seasonal transmission and where EPI coverage may be low especially in the second year of life. Practical implementation challenges, lessons learned for vaccine introduction, and research questions, towards facilitating the introduction of the RTS,S (and other malaria vaccines) in countries with seasonal malaria transmission were discussed.
| S-EPMC10464391 | biostudies-literature
Project description:RTS,S is the sole candidate vaccine shown to provide protection against infection to malaria-naive adults challenged with mosquito-borne homologous falciparum malaria and protection against infection and clinical and severe disease to volunteers in malaria-endemic Africa who were exposed to diverse Plasmodium falciparum strains. In this experiment we profiled gene expression in PBMCs after vaccination with the RTS,S candidate malaria vaccine in a controlled human malaria infection study. Subjects were vaccinated with three doses of the RTS,S candidate malaria vaccine. Blood samples for PBMC isolation and subsequent gene expression analysis were taken on day 0 (0m), day of the third vaccination (8w), 1 day post third vaccination (8w1d), 3 days post third vaccination (8w3d), the day of the infection (10w), 1 day post infection (10w1d), and 5 days post infection (10w5d). After infection the subjects were closely monitored for parasitemia. The response to the controlled infection was recorded as follows: no parasitemia (P, protected), parasitemia in the same time frame as the control group (NP, not protected), parasitemia later than the control group (DL, delayed). In addition to the experimental factors, a confounding factor was identified in the data analysis related to the use of a specific kit batch (Kit A or B).
2017-04-27 | E-MTAB-4629 | biostudies-arrayexpress
Project description:BackgroundMalaria 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.MethodsA cohort of 63 caregivers with a malaria vaccine eligible child was interviewed at three time points over 24 months. A sub-set of 11 caregivers whose eligible children were either partially or non-vaccinated were selected for this sub-analysis. The 5A Taxonomy for root causes of under-vaccination was used to organise the inductively-coded data into categories (awareness, acceptance, access, affordability, and activation) and identify the factors influencing uptake across caregivers. A trajectory analysis was conducted to understand changes in factors over time within each caregiver experience. Caregiver narratives are used to illustrate how the factors influencing uptake were interrelated and changed over time.ResultsLack of awareness, previous negative experiences with routine childhood immunisations and the burden of getting to the health facility contributed to caregivers initially delaying uptake of the vaccine. Over time concerns about vaccine side effects diminished and anticipated vaccination benefits strongly motivated caregivers to vaccinate their children. Persistent health system barriers (e.g., healthcare provider strikes, vaccine stockouts, negative provider attitudes) meant some children missed the first-dose eligibility window by aging-out.ConclusionsCaregivers in this study believed the RTS,S/AS01 to be effective and were motivated to have their children vaccinated. Despite these positive perceptions of the malaria vaccine, uptake was substantially hindered by persistent health system constraints. Negative provider attitudes emerged as a powerful deterrent to attending immunisation services and hampered uptake of the vaccine. Strategies that focus on improving interpersonal communication skills among healthcare providers are needed.
| S-EPMC10657022 | biostudies-literature
Project description:RTS,S/AS01 malaria vaccine received a favorable scientific opinion from the European Medicines Agency (EMA) in July 2015. The World Health Organization (WHO) recommended the pilot introduction of this vaccine in children aged 5 months or older using a vaccination schedule which included 3 initial doses separated by at least 1 month and a 4th dose administered 15-18 months after the 3rd dose. Clinical trials and mathematical models showed that the partial protection against malaria conferred by vaccine RTS,S/AS01 Malaria Vaccine could have a substantial impact on public health if the vaccine was used in association with other control measures for malaria, in particular in highly endemic areas. The most significant impact was observed in children aged 5 months or older who received 4 doses of RTS,S/AS01. Vaccine effectiveness will then be evaluated under real-life conditions in order to determine its impact on mortality, its safety in the context of routine immunization and the feasibility of implementing the 4-dose vaccination schedule requiring new immunization contacts. If successful, this would pave the way for larger-scale implementation.
| S-EPMC6201624 | biostudies-literature
Project description:Identification of gene signatures that are associated with protection in RTS,S malaria vaccination study
2020-04-21 | GSE102288 | GEO
Project description:BackgroundA trial in African children showed that combining seasonal vaccination with the RTS,S/AS01E vaccine with seasonal malaria chemoprevention reduced the incidence of uncomplicated and severe malaria compared with either intervention given alone. Here, we report on the anti-circumsporozoite antibody response to seasonal RTS,S/AS01E vaccination in children in this trial.MethodsSera from a randomly selected subset of children collected before and 1 month after 3 priming doses of RTS,S/AS01E and before and 1 month after 2 seasonal booster doses were tested for anti-circumsporozoite antibodies using enzyme-linked immunosorbent assay. The association between post-vaccination antibody titer and incidence of malaria was explored.ResultsA strong anti-circumsporozoite antibody response to 3 priming doses of RTS,S/AS01E was seen (geometric mean titer, 368.9 enzyme-linked immunosorbent assay units/mL), but titers fell prior to the first booster dose. A strong antibody response to an annual, pre-malaria transmission season booster dose was observed, but this was lower than after the primary vaccination series and lower after the second than after the first booster dose (ratio of geometric mean rise, 0.66; 95% confidence interval [CI], .57-.77). Children whose antibody response was in the upper tercile post-vaccination had a lower incidence of malaria during the following year than children in the lowest tercile (hazard ratio, 0.43; 95% CI, .28-.66).ConclusionsSeasonal vaccination with RTS,S/AS01E induced a strong booster antibody response that was lower after the second than after the first booster dose. The diminished antibody response to the second booster dose was not associated with diminished efficacy.Clinical trials registrationNCT03143218.
| S-EPMC9464075 | biostudies-literature
Project description:Background. Malaria is a major public health burden in sub-Saharan Africa. This study estimated the cost-effectiveness and budget impact of adding four-dose malaria vaccination in infants or children to existing interventions in 41 endemic countries in sub-Saharan Africa. Methods. A static Markov cohort model followed a simulated 2017 birth cohort (36.5 million children) for 15 years in 5-day cycles, comparing three strategies: child vaccination (doses at ages 6, 7.5, 9, and 27 months); infant vaccination (doses at ages 6, 10, and 14 weeks and 21 months); no malaria vaccination. The base-case analysis was conducted from the health system perspective with vaccine price assumed at USD5/dose and annual discounting of 3% for costs and disability-adjusted life-years (DALYs). Efficacy was based on the Phase III RTS,S clinical trial. Results. The model projected that 24.6 million children, or 26.2 million infants, would be vaccinated. Compared with no vaccination, child (infant) vaccination was projected to avert 16.8 million (16 million) cases of malaria and 113,000 (107,000) malaria deaths in the birth cohort over the 15-year period. The incremental cost-effectiveness ratio was USD200/DALY averted (USD225/DALY averted) for child (infant) vaccination, which represents 14% (17%) of the gross domestic product (GDP) per capita threshold. The estimated budget impact was overall larger for infant vaccination but mixed situations occurred across countries. Vaccine price, discount rate, and parasite prevalence had the largest effect on cost-effectiveness. Conclusions. Child vaccination with RTS,S would be more cost-effective than infant vaccination across countries. Adding RTS,S malaria vaccination to existing interventions would be cost-effective assuming one GDP per capita threshold for both child and infant vaccination in all examined countries except for 6 countries with lower transmission.
| S-EPMC6906355 | biostudies-literature
Project description:BackgroundRTS,S is the first malaria vaccine recommended for implementation among young children at risk. However, vaccine efficacy is modest and short-lived. Antibodies play the major role in vaccine-induced immunity, but knowledge on the induction, decay, and determinants of antibody function is limited, especially among children. Antibodies that promote opsonic phagocytosis and other cellular functions appear to be important contributors to RTS,S immunity.MethodsWe studied a phase IIb trial of RTS,S/AS02 conducted in young children in malaria-endemic regions of Mozambique. We evaluated the induction of antibodies targeting the circumsporozoite protein (CSP, vaccine antigen) that interact with Fcγ-receptors (FcRγs) and promote phagocytosis (neutrophils, monocytes, THP-1 cells), antibody-dependent respiratory burst (ADRB) by neutrophils, and natural killer (NK) cell activity, as well as the temporal kinetics of responses over 5 years of follow-up (ClinicalTrials.gov registry number NCT00197041).ResultsRTS,S vaccination induced CSP-specific IgG with FcγRIIa and FcγRIII binding activity and promoted phagocytosis by neutrophils, THP-1 monocytes, and primary human monocytes, neutrophil ADRB activity, and NK cell activation. Responses were highly heterogenous among children, and the magnitude of neutrophil phagocytosis by antibodies was relatively modest, which may reflect modest vaccine efficacy. Induction of functional antibodies was lower among children with higher malaria exposure. Functional antibody magnitude and the functional activity of antibodies largely declined within a year post-vaccination, and decay were highest in the first 6 months, consistent with the decline in vaccine efficacy over that time. Decay rates varied for different antibody parameters and decay was slower for neutrophil phagocytosis. Biostatistical modelling suggested IgG1 and IgG3 contribute in promoting FcγR binding and phagocytosis, and IgG targeting the NANP-repeat and C-terminal regions CSP were similarly important for functional activities.ConclusionsResults provide new insights to understand the modest and time-limited efficacy of RTS,S in children and the induction of antibody functional activities. Improving the induction and maintenance of antibodies that promote phagocytosis and cellular functions, and combating the negative effect of malaria exposure on vaccine responses are potential strategies for improving RTS,S efficacy and longevity.
| S-EPMC9402280 | biostudies-literature