Lassa fever vaccine use cases and demand: Perspectives from select West African experts.

Lassa fever (LF) is a zoonotic viral hemorrhagic disease endemic to several West African countries. Approximately 300-500,000 cases occur annually across all ages with 10-20% case fatality rates. A LF vaccine is a recognized public health priority, with several candidates entering clinical trials. However, the perspectives of regional experts regarding critical vaccine properties, ideal delivery methods, and priority target populations remain unclear. Using a mixed methods approach with a standardized questionnaire, we individually interviewed 8 West African stakeholders, each with extensive knowledge and experience of LF. They strongly favored the use of a mass, proactive campaign strategy to immunize a wide age range of people in high-risk areas, including pregnant women and health care workers. We estimated that these and other plausible delivery scenarios could result in an initial demand of anywhere from 1 to 100 million doses, with most demand coming from Nigeria. These findings may help inform LF vaccine development and deployment efforts.

Costs of human papillomavirus vaccine delivery in low- and middle-income countries: A systematic review.

Vaccines to protect against human papillomavirus (HPV) infection are recommended for all adolescents by the World Health Organization (WHO) and are primarily delivered in school-based settings. This systematic review aims to summarize the available evidence on the cost of HPV vaccine delivery in low- and middle-income countries (LMICs). This updated evidence is eminent given recent global efforts to revitalize HPV vaccine delivery following the COVID-19 pandemic and can be used to inform planning for program sustainability. We carried out a systematic review of published literature reporting the costs of HPV vaccine delivery in LMICs published between 2005 and 2023. Eligibility criteria were developed using the Population, Intervention, Comparator, Outcome (PICO) framework, and studies that reported primary costing data and unit costs of HPV vaccine delivery were included. From the included studies, we extracted data such as phase of HPV vaccine implementation when costing was done, delivery strategy, and unit costs. Unit costs were converted into 2022 US$ for comparability. All included studies underwent critical appraisal using an adapted framework including Consolidated Health Economics Evaluation Reporting Standards criteria, the WHO-led consensus statement on vaccine delivery costing, and other frameworks. Our research identified 226 records, of which 15 met our inclusion criteria. Most studies (64 %) were carried out in African countries and during HPV vaccine pilots or demonstrations (60 %). Vaccine delivery cost ranged from $0.31 to $24.07 per dose for financial costs and $1.48 to $48.70 per dose for economic costs. The critical appraisal showed that most studies did not describe the uncertainty of reported delivery cost. Our systematic review evidence suggests that HPV vaccine delivery costs vary widely depending on country and stage of implementation when costing was done. Areas for further research include costing when programs are beyond the introduction phase and in LMICs outside of Africa.

Human papillomavirus (HPV) vaccination program in Sri Lanka: Ongoing costs and operational context of a routinized program.

Existing evidence on the cost of human papillomavirus (HPV) vaccination programs has focused on pilot and demonstration projects or initial introductions, which resulted in a perceived high cost. We aimed to study the ongoing cost and operational context of an established HPV vaccination program in Sri Lanka. We conducted a retrospective operational research and microcosting study focusing on 2019. We collected data from 30 divisional health units, 10 districts, and the central level. We then evaluated financial and economic costs, reported by level of the health system, program activity, cost types, and per dose delivered. In 2019, Sri Lanka delivered a total of 314,815 doses of HPV vaccine. In our study sample, 95 % of the HPV vaccination sessions took place at schools, with peaks of delivery in February-March and September-October. The weighted mean financial cost per dose delivered was $0.27 (95 % confidence interval [CI]: $0.15-$0.39) and the economic cost per dose was $3.88 (95 % CI: $2.67-$5.10), excluding the cost of vaccines and supplies. Most of the cost was borne by the divisional health unit level. Service delivery and social mobilization were major contributors to overall costs at the divisional health unit level, and vaccine collection or distribution and storage were the most costly activities at the district and central levels. Cost drivers included the opportunity cost of health worker and non-health worker time at the divisional health unit level and capital costs for vehicles and equipment, along with fuel, maintenance, and energy, at the district and central levels. This study provides new evidence on the cost and cost drivers of a routinized HPV vaccination program. Results can be used for financial planning purposes in Sri Lanka and may inform other countries as they consider use of HPV vaccines.

Cost of illness due to respiratory syncytial virus acute lower respiratory tract infection among infants hospitalized in Argentina.

BACKGROUND: Information is scarce regarding the economic burden of respiratory syncytial virus (RSV) disease in low-resource settings. This study aimed to estimate the cost per episode of hospital admissions due to RSV severe disease in Argentina. METHODS: This is a prospective cohort study that collected information regarding 256 infants under 12 months of age with acute lower respiratory tract infection (ALRTI) due to RSV in two public hospitals of Buenos Aires between 2014 and 2016. Information on healthcare resource use was collected from the patient's report and its associated costs were estimated based on the financial database and account records of the hospitals. We estimated the total cost per hospitalization due to RSV using the health system perspective. The costs were estimated in US dollars as of December 2022 (1 US dollar = 170 Argentine pesos). RESULTS: The mean costs per RSV hospitalization in infants was US$587.79 (95% confidence interval [CI] $535.24 - $640.33). The mean costs associated with pediatric intensive care unit (PICU) admission more than doubled from those at regular pediatric wards ($1,556.81 [95% CI $512.21 - $2,601.40] versus $556.53 [95% CI $514.59 - $598.48]). CONCLUSIONS: This study shows the direct economic impact of acute severe RSV infection on the public health system in Argentina. The estimates obtained from this study could be used to inform cost-effectiveness analyses of new preventive RSV interventions being developed.

Reassessing potential economic value and health impact of effective Shigella vaccines.

The gram-negative bacterium Shigella is a leading cause of diarrheal morbidity and mortality in children in low- and middle-income countries. Several promising vaccine candidates are in late stages of clinical development against this increasingly antibiotic-resistant pathogen. However, considering the increasingly crowded and costly paediatric immunization schedule, and likely advent of other important new vaccines, it is unclear whether introduction of a Shigella vaccine would represent a high priority for international agencies or health ministries in low- and middle-income countries. To determine whether there is a compelling public health value proposition for a Shigella vaccine, we used the World Health Organization's Full Value of Vaccine Assessment analytic framework and formulated five broad scientific, policy, economic and commercial-related propositions regarding the development of a Shigella vaccine. We also explored the current regulatory, clinical, policy and commercial challenges to a Shigella-containing combination vaccine development and adoption. Through a series of literature reviews, expert consultations, social science field studies and model-based analyses, we addressed each of these propositions. As described in a series of separate publications that are synthesized here, we concluded that the economic and public health value of a Shigella vaccine may be greater than previously recognized, particularly if it is found to also be effective against less severe forms of diarrheal disease and childhood stunting. The decision by pharmaceutical companies to develop a standalone vaccine or a multipathogen combination will be a key factor in determining its relative prioritization by various stakeholders in low- and middle-income countries.

La bactérie à Gram négatif Shigella est l'une des principales causes de morbidité et de mortalité diarrhéiques chez les enfants des pays à revenu faible et intermédiaire. Plusieurs candidats vaccins prometteurs sont en phase avancée de conception clinique contre cet agent pathogène qui connaît une antibiorésistance croissante. Toutefois, compte tenu du calendrier de vaccination pédiatrique de plus en plus chargé et coûteux et de l'arrivée probable d'autres nouveaux vaccins importants, il n'est pas certain que la mise sur le marché d'un vaccin contre Shigella constitue une priorité élevée pour les agences internationales ou les ministères de la Santé des pays à revenu faible ou intermédiaire. Pour déterminer l'existence d'un intérêt convaincant en matière de santé publique pour un vaccin contre Shigella, nous avons utilisé le cadre analytique du cadre d'évaluation de la valeur totale des vaccins de l'Organisation mondiale de la santé et formulé cinq propositions scientifiques, politiques, économiques et commerciales générales concernant la conception d'un vaccin contre Shigella. Nous avons également étudié les défis en matière réglementaire, clinique, politique et commerciale qui se posent actuellement à la mise au point et à l'adoption d'un vaccin combiné contenant des Shigella. Nous avons abordé chacune de ces propositions au moyen d'une série d'analyses documentaires, de consultations d'experts, d'études de terrain en sciences sociales et d'analyses basées sur des modèles. Comme décrit dans une série de publications distinctes résumées ici, nous avons conclu que la valeur économique et sur le plan de la santé publique d'un vaccin contre Shigella pourrait être plus importante que ce qui était considéré précédemment, en particulier s'il s'avère que ce vaccin s'avère également efficace contre les formes moins sévères de maladies diarrhéiques et de retard de croissance chez l'enfant. La décision d'entreprises pharmaceutiques de mettre au point un vaccin autonome ou une combinaison de plusieurs agents pathogènes sera un facteur clé dans la détermination de sa priorité relative par les différentes parties prenantes dans les pays à revenu faible et intermédiaire.

La bacteria gramnegativa Shigella es una de las principales causas de morbilidad y mortalidad por diarrea en niños de países de ingresos bajos y medios. Varias vacunas candidatas y prometedoras se encuentran en las últimas fases de desarrollo clínico contra este patógeno cada vez más resistente a los antibióticos. Sin embargo, teniendo en cuenta el esquema de inmunización pediátrica, cada vez más saturado y costoso, y la probable llegada de otras vacunas nuevas importantes, no está claro si la introducción de una vacuna contra la Shigella representaría una alta prioridad para los organismos internacionales o los ministerios de salud de los países de ingresos bajos y medios. Para determinar si existe una propuesta de valor de salud pública convincente para una vacuna contra la Shigella, utilizamos el marco de análisis Full Value of Vaccine Assessment de la Organización Mundial de la Salud y formulamos cinco amplias propuestas científicas, políticas, económicas y comerciales relacionadas con el desarrollo de una vacuna contra la Shigella. También exploramos los actuales desafíos reglamentarios, clínicos, políticos y comerciales para el desarrollo y la adopción de una vacuna combinada que contenga Shigella. Mediante una serie de revisiones bibliográficas, consultas a expertos, estudios de campo de ciencias sociales y análisis basados en modelos, abordamos cada una de estas proposiciones. Como se describe en una serie de publicaciones separadas que se sintetizan aquí, llegamos a la conclusión de que el valor económico y de salud pública de una vacuna contra la Shigella puede ser mayor de lo que se reconocía anteriormente, en particular si se descubre que también es eficaz contra formas menos graves de enfermedad diarreica y retraso del crecimiento infantil. La decisión de las empresas farmacéuticas de desarrollar una vacuna independiente o una combinación multipatógena será un factor clave a la hora de determinar su prioridad relativa por parte de las diversas partes interesadas en los países de ingresos bajos y medios.

Cost of Acute and Sequelae Care for Japanese Encephalitis Patients, Bangladesh, 2011-2021.

Japanese encephalitis (JE) is associated with an immense social and economic burden. Published cost-of-illness data come primarily from decades-old studies. To determine the cost of care for patients with acute JE and initial and long-term sequelae from the societal perspective, we recruited patients with laboratory-confirmed JE from the past 10 years of JE surveillance in Bangladesh and categorized them as acute care, initial sequalae, and long-term sequelae patients. Among 157 patients, we categorized 55 as acute, 65 as initial sequelae (53 as both categories), and 90 as long-term sequelae. The average (median) societal cost of an acute JE episode was US $929 ($909), of initial sequelae US $75 ($33), and of long-term sequelae US $47 ($14). Most families perceived the effect of JE on their well-being to be extreme and had sustained debt for JE expenses. Our data about the high cost of JE can be used by decision makers in Bangladesh.

Estimating the global impact of rotavirus vaccines on child mortality.

OBJECTIVES: We estimated the global impact of rotavirus vaccines on deaths among children under five years old by year. METHODS: We used a proportionate outcomes model with a finely disaggregated age structure to estimate rotavirus deaths prevented by vaccination over the period 2006-2019 in 186 countries. We ran deterministic and probabilistic uncertainty analyses and compared our estimates to surveillance-based estimates in 20 countries. RESULTS: We estimate that rotavirus vaccines prevented 139,000 under-five rotavirus deaths (95% uncertainty interval 98,000-201,000) in the period 2006-2019. In 2019 alone, rotavirus vaccines prevented 15% (95% uncertainty interval 11-21%) of under-five rotavirus deaths (0.5% of child mortality). Assuming global use of rotavirus vaccines and coverage equivalent to other co-administered vaccines could prevent 37% of under-five rotavirus deaths (1.2% of child mortality). Our estimates were sensitive to the choice of rotavirus mortality burden data and several vaccine impact modeling assumptions. The World Health Organization's recommendation to remove age restrictions in 2012 could have prevented up to 17,000 rotavirus deaths in the period 2013-2019. Our modeled estimates of rotavirus vaccine impact were broadly consistent with estimates from post-vaccination surveillance sites. CONCLUSION: Rotavirus vaccines have made a valuable contribution to global public health. Enhanced rotavirus mortality prevention strategies are needed in countries with high mortality in under-5-year-old children.

Report of the WHO technical consultation on the evaluation of respiratory syncytial virus prevention cost effectiveness in low- and middle-income countries, April 7-8, 2022.

Policymakers often rely on impact and cost-effectiveness evaluations to inform decisions about the introduction of health interventions in low- and middle-income countries (LMICs); however, cost-effectiveness results for the same health intervention can differ by the choice of parameter inputs, modelling assumptions, and geography. Anticipating the near-term availability of new respiratory syncytial virus (RSV) prevention products, WHO convened a two-day virtual consultation in April 2022 with stakeholder groups and global experts in health economics, epidemiology, and vaccine implementation. The objective was to review methods, parameterization, and results of existing cost-effectiveness analyses for RSV prevention in LMICs; identify the most influential inputs and data limitations; and recommend and prioritize future data gathering and research to improve RSV prevention impact estimates in LMICs. Epidemiological parameters identified as both influential and uncertain were those associated with RSV hospitalization and death, specifically setting-specific hospitalization rates and RSV-attributable death rates. Influential economic parameters included product price, delivery costs, willingness-to-pay for health on the part of potential donors, and the cost of RSV-associated hospitalization. Some of the influential parameters identified at this meeting should be more precisely measured by further research. Other influential economic parameters that are highly uncertain may not be resolved, and it is appropriate to use sensitivity analyses to explore these within cost-effectiveness evaluations. This report highlights the presentations and major discussions of the meeting.

Impact and cost-effectiveness of strategies to prevent respiratory syncytial virus (RSV) disease in Vietnam: A modelling study.

BACKGROUND: New prevention strategies for respiratory syncytial virus (RSV) are emerging, but it is unclear if they will be cost-effective in low- and middle-income countries. We evaluated the potential impact and cost-effectiveness of two strategies to prevent RSV disease in young children in Vietnam. METHODS: We used a static cohort model with a finely disaggregated age structure (weeks of age <5 years) to calculate the RSV disease burden in Vietnam, with and without a single dose of maternal vaccine (RSVpreF, Pfizer) or of monoclonal antibody (Nirsevimab, Sanofi, Astra Zeneca). Each strategy was compared to no pharmaceutical intervention, and to each other. We assumed both strategies would be administered year round over a ten-year period. The primary outcome measure was the cost per disability-adjusted life year (DALY) averted, from a societal perspective. We ran probabilistic and deterministic uncertainty analyses. RESULTS: With central input assumptions for RSVpreF vaccine ($25/dose, 69 % efficacy, 6 months protection) and Nirsevimab ($25/dose, 77 % efficacy, 5 months protection), both options had similar cost-effectiveness ($3442 versus $3367 per DALY averted) when compared separately to no pharmaceutical intervention. RSVpreF vaccine had a lower net cost than Nirsevimab (net discounted cost of $213 m versus $264 m) but prevented fewer RSV deaths (24 % versus 31 %). Our results were very sensitive to assumptions about the dose price, efficacy, and duration of protection. At $5/dose and a willingness-to-pay threshold of 0.5 times the national GDP per capita, both prevention strategies are cost-effective. CONCLUSIONS: RSVpreF vaccine and Nirsevimab may be cost-effective in Vietnam if appropriately priced.

Rotavirus vaccine product switch in Ghana: An assessment of service delivery costs, switching costs, and cost-effectiveness.

Ghana introduced rotavirus vaccine (ROTARIX 1-dose presentation) into the routine national immunization program in 2012 and switched to a different product (ROTAVAC 5-dose presentation) in 2020. ROTAVAC has a lower price per dose (US$0.85 versus US$2.15 for ROTARIX) and smaller cold chain footprint but requires more doses per regimen (three versus two). This study estimates the supply chain and service delivery costs associated with each product, the costs involved in switching products, and compares the cost-effectiveness of both products over the next ten years. We estimated the supply chain and service delivery costs associated with ROTARIX and ROTAVAC (evaluating both the 5-dose and 10-dose presentations) using primary data collected from health facilities in six of the 14 regions in the country. We estimated the costs of switching from ROTARIX to ROTAVAC using information collected from key informant interviews and financial records provided by the government. All costs were reported in 2020 US$. We used the UNIVAC decision-support model to evaluate the cost-effectiveness (US$ per disability-adjusted life-year (DALY) averted from government and societal perspectives) of ROTARIX and ROTAVAC (5-dose or 10-dose presentations) compared to no vaccination, and to each other, over a ten-year period (2020 to 2029). We ran probabilistic sensitivity analyses and other threshold analyses. The supply chain and service delivery economic cost per dose was $2.40 for ROTARIX, $1.81 for ROTAVAC 5-dose, and $1.76 for ROTAVAC 10-dose. The financial and economic cost of switching from ROTARIX to ROTAVAC 5-dose was $453,070 and $883,626, respectively. Compared to no vaccination, the cost per DALY averted was $360 for ROTARIX, $298 for ROTAVAC 5-dose, and $273 for ROTAVAC 10-dose. ROTAVAC 10-dose was the most cost-effective option and would be cost-effective at willingness-to-pay thresholds exceeding 0.12 times the national GDP per capita ($2,206 in the year 2020). The switch from ROTARIX to ROTAVAC 5-dose in 2020 was cost-saving. Rotavirus vaccination is highly cost-effective in Ghana. A switch from ROTAVAC 5-dose to ROTAVAC 10-dose would be cost-saving and should be considered.

Assessment of gestational age at antenatal care visits among Kenyan women to inform delivery of a maternal respiratory syncytial virus (RSV) vaccine in low- and middle-income countries.

Background: Maternal respiratory syncytial virus (RSV) vaccines that are likely to be implementable in low- and middle-income countries (LMICs) are in final stages of clinical trials. Data on the number of women presenting for antenatal care (ANC) per day and proportion attending within the proposed gestational window for vaccine delivery, is a prerequisite to guide development of vaccine vial size and inform vaccine uptake in this setting. Methods: We undertook administrative review and abstraction of ANC attendance records from 2019 registers of 24 selected health facilities, stratified by the level of care, from Kilifi, Siaya and Nairobi counties in Kenya. Additional data were obtained from Mother and Child Health (MCH) booklets of women in each of the Health and Demographic Surveillance System (HDSS) areas of Kilifi, Nairobi and Siaya. Data analysis involved descriptive summaries of the number (mean, median) and proportion of women attending ANC within the gestational window period of 28-32 weeks and 24-36 weeks. Results: A total of 62,153 ANC records were abstracted, 33,872 from Kilifi, 19,438 from Siaya and 8,943 from Nairobi Counties. The median (Interquartile range, IQR) number of women attending ANC per day at a gestational age window of 28-32 and 24-36 weeks, respectively, were: 4 (2-6) and 7 (4-12) in dispensaries, 5 (2-9) and 10 (4-19) in health centres and 6 (4-11) and 16 (10-26) in county referral hospitals. In the HDSS areas of Kilifi, Siaya and Nairobi, pregnant women attending at least one ANC visit, within a window of 28-32 weeks, were: 77% (360/470), 75% (590/791) and 67% (547/821), respectively. Conclusions: About 70% of pregnant women across three distinct geographical regions in Kenya, attend ANC within 28-32 weeks of gestation. A multidose vial size with about five doses per vial, approximates daily ANC attendance and would not incur possible wastage in similar settings.

Value profile for respiratory syncytial virus vaccines and monoclonal antibodies.

Respiratory syncytial virus (RSV) is the predominant cause of acute lower respiratory infection (ALRI) in young children worldwide, yet no licensed RSV vaccine exists to help prevent the millions of illnesses and hospitalizations and tens of thousands of young lives taken each year. Monoclonal antibody (mAb) prophylaxis exists for prevention of RSV in a small subset of very high-risk infants and young children, but the only currently licensed product is impractical, requiring multiple doses and expensive for the low-income settings where the RSV disease burden is greatest. A robust candidate pipeline exists to one day prevent RSV disease in infant and pediatric populations, and it focuses on two promising passive immunization approaches appropriate for low-income contexts: maternal RSV vaccines and long-acting infant mAbs. Licensure of one or more candidates is feasible over the next one to three years and, depending on final product characteristics, current economic models suggest both approaches are likely to be cost-effective. Strong coordination between maternal and child health programs and the Expanded Program on Immunization will be needed for effective, efficient, and equitable delivery of either intervention. This 'Vaccine Value Profile' (VVP) for RSV is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations, and in collaboration with stakeholders from the WHO headquarters. All contributors have extensive expertise on various elements of the RSV VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Impact, cost-effectiveness, and budget implications of HPV vaccination in Kenya: A modelling study.

BACKGROUND: Sub-Saharan Africa has the highest rate of cervical cancer cases and deaths worldwide. Kenya introduced a quadrivalent HPV vaccine (GARDASIL, hereafter referred to as GARDASIL-4) for ten-year-old girls in late 2019 with donor support from Gavi, the Vaccine Alliance. As Kenya may soon graduate from Gavi support, it is important to evaluate the potential cost-effectiveness and budget impact of the current HPV vaccine, and potential alternatives. METHODS: We used a proportionate outcomes static cohort model to evaluate the annual budget impact and lifetime cost-effectiveness of vaccinating ten-year-old girls over the period 2020-2029. We included a catch-up campaign for girls aged 11-14 years in 2020. We estimated cervical cancer cases, deaths, disability adjusted life years (DALYs), and healthcare costs (government and societal perspective) expected to occur with and without vaccination over the lifetimes of each cohort of vaccinated girls. For each of the four products available globally (CECOLIN©, CERVARIX©, GARDASIL-4©, and GARDASIL-9 ©), we estimated the cost (2021 US$) per DALY averted compared to no vaccine and to each other. Model inputs were obtained from published sources, as well as local stakeholders. RESULTS: We estimated 320,000 cases and 225,000 deaths attributed to cervical cancer over the lifetimes of the 14 evaluated birth cohorts. HPV vaccination could reduce this burden by 42-60 %. Without cross-protection, CECOLIN had the lowest net cost and most attractive cost-effectiveness. With cross-protection, CERVARIX was the most cost-effective. Under either scenario the most cost-effective vaccine had a 100 % probability of being cost-effective at a willingness-to-pay threshold of US$ 100 (5 % of Kenya's national gross domestic product per capita) compared to no vaccination. Should Kenya reach its target of 90 % coverage and graduate from Gavi support, the undiscounted annual vaccine program cost could exceed US$ 10 million per year. For all three vaccines currently supported by Gavi, a single-dose strategy would be cost-saving compared to no vaccination. CONCLUSION: HPV vaccination for girls is highly cost-effective in Kenya. Compared to GARDASIL-4, alternative products could provide similar or greater health benefits at lower net costs. Substantial government funding will be required to reach and sustain coverage targets as Kenya graduates from Gavi support. A single dose strategy is likely to have similar benefits for less cost.

Estimating the cost of illness of acute Japanese encephalitis and sequelae care in Vietnam and Laos: A cross-sectional study.

BACKGROUND: Japanese encephalitis (JE) is a leading cause of acute encephalitis syndrome and resulting neurological disability in Asia and the Western Pacific. This study aims to estimate the cost of acute care, initial rehabilitation and sequelae care, in Vietnam and Laos. METHODOLOGY: We conducted a cross-sectional retrospective study using a micro-costing approach from the health system and household perspectives. Out-of-pocket direct medical and non-medical costs, indirect costs, and family impact were reported by patients and/or caregivers. Hospitalization costs were extracted from hospital charts. Acute costs covered expenditures from pre-hospital to follow-up visits while sequelae care costs were estimated from expenditures in the last 90 days. All costs are in 2021 US dollars. PRINCIPAL FINDINGS: 242 patients in two major sentinel sites in the North and South of Vietnam and 65 patients in a central hospital in Vientiane, Laos, with laboratory-confirmed JE were recruited regardless of age, sex, and ethnicity. In Vietnam, the mean total cost was $3,371 per acute JE episode (median $2,071, standard error [SE] $464) while annual costs were $404 for initial sequelae care (median $0, SE $220) and $320 for long-term sequelae care (median $0, SE $108). In Laos, the mean hospitalization costs in acute stage were $2,005 (median $1,698, SE $279) and the mean annual costs were $2,317 (median $0, SE $2,233) for initial sequelae care and $89 (median $0, SE $57) for long-term sequelae care. In both countries, most patients did not seek care for their sequelae. Families perceived extreme impact from JE and 20% to 30% of households still had sustained debts years after acute JE. CONCLUSIONS: JE patients and families in Vietnam and Laos suffer extreme medical, economic, and social hardship. This has policy implications for improving JE prevention in these two JE-endemic countries.

Respiratory Syncytial Virus (RSV) Disease and Prevention Products: Knowledge, Attitudes, and Preferences of Kenyan Healthcare Workers in Two Counties in 2021.

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection (LRTI) among infants under 6 months of age. Yet, in Kenya, little is known about healthcare workers' (HCWs) knowledge, attitudes, and perceptions around RSV disease and the prevention products under development. Between September and October 2021, we conducted a mixed methods cross-sectional survey to assess HCWs' knowledge, attitudes, and perceptions of RSV disease and RSV vaccinations in two counties. We enrolled HCWs delivering services directly at maternal and child health (MCH) departments in selected health facilities (frontline HCWs) and health management officers (HMOs). Of the 106 respondents, 94 (88.7%) were frontline HCWs, while 12 were HMOs. Two of the HMOs were members of the Kenya National Immunization Technical Advisory Group (KENITAG). Of the 104 non-KENITAG HCWs, only 41 (39.4%) had heard about RSV disease, and 38/41 (92.7%) felt that pregnant women should be vaccinated against RSV. Most participants would recommend a single-dose vaccine schedule (n = 62, 58.5%) for maximal adherence and compliance (n = 38/62, 61.3%), single dose/device vaccines (n = 50/86, 58.1%) to prevent wastage and contamination, and maternal vaccination through antenatal care clinics (n = 53, 50%). We found the need for increased knowledge about RSV disease and prevention among Kenyan HCWs.

Impact and Cost-Effectiveness of Alternative Human Papillomavirus Vaccines for Preadolescent Girls in Mozambique: A Modelling Study.

Mozambique has one of the highest rates of cervical cancer in the world. Human papillomavirus (HPV) vaccination was introduced in 2021. This study evaluated the health and economic impact of the current HPV vaccine (GARDASIL® hereafter referred to as GARDASIL-4) and two other vaccines (CECOLIN® and CERVARIX®) that could be used in the future. A static cohort model was used to estimate the costs and benefits of vaccinating girls in Mozambique over the period 2022-2031. The primary outcome measure was the incremental cost per disability-adjusted life-year averted from a government perspective. We conducted deterministic and probabilistic sensitivity analyses. Without cross-protection, all three vaccines averted approximately 54% cervical cancer cases and deaths. With cross-protection, CERVARIX averted 70% of cases and deaths. Without Gavi support, the discounted vaccine program costs ranged from 60 million to 81 million USD. Vaccine program costs were approximately 37 million USD for all vaccines with Gavi support. Without cross-protection, CECOLIN was dominant, being cost-effective with or without Gavi support. With cross-protection and Gavi support, CERVARIX was dominant and cost-saving. With cross-protection and no Gavi support, CECOLIN had the most favorable cost-effectiveness ratio. Conclusions: At a willingness-to-pay (WTP) threshold set at 35% of Gross Domestic Product (GDP) per capita, HPV vaccination is cost-effective in Mozambique. The optimal vaccine choice depends on cross-protection assumptions.

Optimizing next-generation RSV prevention in Mali: A cost-effectiveness analysis of pediatric vaccination, maternal vaccination, and extended half-life monoclonal antibody immunoprophylaxis.

Respiratory syncytial virus (RSV) is the most common cause of early childhood lower respiratory tract infection (LRTI) in low- and middle-income countries (LMICs). Maternal vaccines, birth-dose extended half-life monoclonal antibodies (mAbs), and pediatric vaccines are under development for prevention of respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) in young children. We analyzed the health and economic impact of RSV interventions used alone or in combinations in Mali. We modeled age-specific and season-specific risks of RSV LRTI in children through three years, using WHO Preferred Product Characteristics and data generated in Mali. Health outcomes included RSV LRTI cases, hospitalizations, deaths, and disability-adjusted life-years (DALYs). We identified the optimal combination of products across a range of scenarios. We found that mAb delivered at birth could avert 878 DALYs per birth cohort at an incremental cost-effectiveness ratio (ICER) of $597 per DALY averted compared to no intervention if the product were available at $1 per dose. Combining mAb with pediatric vaccine administered at 10/14 weeks, 1947 DALYs would be prevented. The ICER of this combination strategy is $1514 per DALY averted compared to mAb alone. Incorporating parameter uncertainty, mAb alone is likely to be optimal from the societal perspective at efficacy against RSV LRTI above 66%. The optimal strategy was sensitive to economic considerations, including product prices and willingness-to-pay for DALYs. For example, the combination of mAb and pediatric vaccine would be optimal from the government perspective at a willingness-to-pay above $775 per DALY. Maternal vaccine alone or in combination with other interventions was never the optimal strategy, even for high vaccine efficacy. The same was true for pediatric vaccine administered at 6/7 months. At prices comparable to existing vaccine products, extended half-life RSV mAbs would be impactful and efficient components of prevention strategies in LMICs such as Mali.

Potential impact and cost-effectiveness of Shigella vaccination in 102 low-income and middle-income countries in children aged 5 years or younger: a modelling study.

BACKGROUND: Vaccine impact and cost-effectiveness models have mostly focused on acute burden. Shigella-attributable moderate-to-severe diarrhoea has been shown to be associated with childhood linear growth faltering. Evidence also links less severe diarrhoea to linear growth faltering. As Shigella vaccines are in late stages of clinical development, we aimed to estimate the potential impact and cost-effectiveness of vaccination against Shigella burden that includes stunting and the acute burden attributable to less severe diarrhoea and moderate-to-severe diarrhoea. METHODS: We used a simulation model to estimate Shigella burden and potential vaccination in children aged 5 years or younger from 102 low-income to middle-income countries from 2025 to 2044. Our model included stunting associated with Shigella-related moderate-to-severe diarrhoea and less severe diarrhoea and we explored vaccination impact on health and economic outcomes. FINDINGS: We estimate 109 million (95% uncertainty interval [UI] 39-204) Shigella-attributable stunting cases and 1·4 million (0·8-2·1) deaths in unvaccinated children over 20 years. We project that Shigella vaccination could avert 43 million (13-92) stunting cases and 590 000 (297 000-983 000) deaths over 20 years. The overall mean incremental cost-effectiveness ratio (ICER) was US$849 (95% uncertainty interval 423-1575; median $790 [IQR 635-1005]) per disability-adjusted life-year averted. Vaccination was most cost-effective in the WHO African region and in low-income countries. Including the burden of Shigella-related less severe diarrhoea improved mean ICERs by 47-48% for these groups and substantially improved ICERs for other regions. INTERPRETATION: Our model suggests that Shigella vaccination would be a cost-effective intervention, with a substantial impact in specific countries and regions. Other regions could potentially benefit upon the inclusion of the burden of Shigella-related stunting and less severe diarrhoea in the analysis. FUNDING: Bill & Melinda Gates Foundation and Wellcome Trust.

Projecting the long-term economic benefits of reducing Shigella-attributable linear growth faltering with a potential vaccine: a modelling study.

BACKGROUND: Linear growth is an important outcome of child development with implications for economic productivity. Enteric infections, particularly Shigella, have been linked to linear growth faltering (LGF). However, benefits from potential reductions in LGF are rarely included in economic analyses of enteric infections. We aimed to quantify the economic benefits of vaccination related to reduced Shigella-attributable disease and associated LGF compared with the net costs of a vaccine programme. METHODS: In this benefit-cost analysis, we modelled productivity benefits in 102 low-income and middle-income countries that had recent stunting estimates available, at least one Shigella-attributable death annually, and available economic data, particularly on gross national income and growth rate projections. We modelled benefits strictly related to linear growth improvements and no other benefits associated with reducing diarrhoeal burden. The effect size in each country was calculated as shifts in height-for-age Z score (HAZ), representing population average changes for preventing Shigella-attributable less-severe diarrhoea and moderate-to-severe diarrhoea separately for children younger than 5 years. Benefits data were calculated per country and combined with estimated net costs of the vaccine programme in the form of benefit-cost ratios (BCRs); BCRs above parity, or $1 in benefits per $1 in costs (with a 10% margin representing borderline results: 1·10:1), were considered cost-beneficial. Countries were aggregated for analysis by WHO region, World Bank income category, and eligibility for support from Gavi, the Vaccine Alliance. FINDINGS: In the base-case scenario, all regions exhibited cost-beneficial results, with the South-East Asia region and Gavi-eligible countries exhibiting the highest BCRs (21·67 for the South-East Asia region and 14·45 for Gavi-eligible countries), and the Eastern Mediterranean region yielding the lowest BCRs (2·90). All regions exhibited cost-beneficial results from vaccination, except in more conservative scenarios (eg, those assuming early retirement ages and higher discount rates). Our findings were sensitive to assumed returns for increased height, assumptions about vaccine efficacy against linear growth detriments, the anticipated shift in HAZ, and discount rate. Incorporating the productivity benefits of LGF reduction into existing cost-effectiveness estimates resulted in longer-term cost-savings in nearly all regions. INTERPRETATION: LGF is a secondary outcome of Shigella infection and reduction in LGF is not often quantified as a health or economic benefit of vaccination. However, even under conservative assumptions, a Shigella vaccine only moderately effective against LGF could pay for itself from productivity gains alone in some regions. We recommend that LGF be considered in future models assessing the economic and health impacts of interventions preventing enteric infections. Further research is needed on vaccine efficacy against LGF to inform such models. FUNDING: Bill & Melinda Gates Foundation, Wellcome Trust.

Cost of introducing and delivering malaria vaccine (RTS,S/AS01E) in areas of seasonal malaria transmission, Mali and Burkina Faso.

BACKGROUND: The WHO recommends use of the RTS,S/AS01E (RTS,S) malaria vaccine for young children living in areas of moderate to high Plasmodium falciparum malaria transmission and suggests countries consider seasonal vaccination in areas with highly seasonal malaria. Seasonal vaccination is uncommon and may require adaptations with potential cost consequences. This study prospectively estimates cost of seasonal malaria vaccine delivery in Mali and Burkina Faso. METHODS: Three scenarios for seasonal vaccine delivery are costed (1) mass campaign only, (2) routine Expanded Programme on Immunisation (EPI) and (3) mixed delivery (mass campaign and routine EPI)), from the government's perspective. Resource use data are informed by previous new vaccine introductions, supplemented with primary data from a sample of health facilities and administrative units. FINDINGS: At an assumed vaccine price of US $5 per dose, the economic cost per dose administered ranges between $7.73 and $8.68 (mass campaign), $7.04 and $7.38 (routine EPI) and $7.26 and $7.93 (mixed delivery). Excluding commodities, the cost ranges between $1.17 and $2.12 (mass campaign), $0.48 and $0.82 (routine EPI) and $0.70 and $1.37 (mixed delivery). The financial non-commodity cost per dose administered ranges between $0.99 and $1.99 (mass campaign), $0.39 and $0.76 (routine EPI) and $0.58 and $1.28 (mixed delivery). Excluding commodity costs, service delivery is the main cost driver under the mass campaign scenario, accounting for 36% to 55% of the financial cost. Service delivery accounts for 2%-8% and 12%-23% of the total financial cost under routine EPI and mixed delivery scenarios, respectively. CONCLUSION: Vaccine delivery using the mass campaign approach is most costly followed by mixed delivery and routine EPI delivery approaches, in both countries. Our cost estimates provide useful insights for decisions regarding delivery approaches, as countries plan the malaria vaccine rollout.