scholarly journals The future of a partially effective HIV vaccine: assessing limitations at the population level

2019 ◽  
Author(s):  
Christian Selinger ◽  
Dobromir T. Dimitrov ◽  
Philip Welkhoff ◽  
Anna Bershteyn
Keyword(s):  
Scale Up ◽  
Population Level ◽  
Cost Effective ◽  
Hiv Vaccine ◽  
Generation Vaccine ◽  
Vaccine Impact ◽  
The One ◽  
Time Required ◽  
The Impact ◽  
Roll Out

AbstractObjectivesMathematical models have unanimously predicted that a first-generation HIV vaccine would be useful and cost-effective to roll out, but that its overall impact would be insufficient to reverse the epidemic. Here, we explore what factors contribute most to limiting the impact of such a vaccine.MethodsRanging from a theoretical ideal to a more realistic regimen, mirroring the one used in the currently ongoing trial in South Africa (HVTN 702), we model a nested hierarchy of vaccine attributes such as speed of roll-out, efficacy, and retention of booster doses.ResultsThe predominant reasons leading to a substantial loss of vaccine impact on the HIV epidemic are the time required to scale up mass vaccination, limited durability and waning of efficacy.ConclusionsA partially effective HIV vaccine will be a critical milestone for the development of a highly effective, durable, and scalable next-generation vaccine. Accelerated development, expedited vaccine availability, and improved immunogenicity are the main attributes of a vaccine that could dramatically reverse the course of the epidemic in highly endemic countries.

scholarly journals Targeting and Vaccine Durability Are Key for Population-level Impact and Cost-Effectiveness of a Pox-Protein HIV Vaccine Regimen in South Africa

2018 ◽  
Author(s):  
Christian Selinger ◽  
Anna Bershteyn ◽  
Dobromir T. Dimitrov ◽  
Blythe J.S. Adamson ◽  
Paul Revill ◽  
...  
Keyword(s):  
South Africa ◽  
Cost Effectiveness ◽  
Targeted Delivery ◽  
Scale Up ◽  
Vaccine Trial ◽  
Population Level ◽  
Cost Effective ◽  
Hiv Vaccine ◽  
Sub Saharan Africa ◽  
Age Cohorts

AbstractBackgroundRV144 is to date the only HIV vaccine trial to demonstrate efficacy, albeit rapidly waning over time. The HVTN 702 trial is currently evaluating in South Africa a similar vaccine formulation to that of RV144 for subtype C HIV with additional boosters (pox-protein regimen). Using a detailed stochastic individualbased network model of disease transmission calibrated to the HIV epidemic, we investigate population-level impact and maximum cost of an HIV vaccine to remain cost-effective.MethodsConsistent with the original pox-protein regimen, we model a primary series of five vaccinations meeting the goal of 50% cumulative efficacy 24 months after the first dose and include two-yearly boosters that maintain durable efficacy over 10 years. We simulate vaccination programs in South Africa starting in 2027 under various vaccine targeting and HIV treatment and prevention assumptions.ResultsOur analysis shows that this partially effective vaccine could prevent, at catchup vaccination with 60% coverage, up to 941,000 (15.6%) new infections between 2027 and 2047 assuming current trends of antiretroviral treatment. An impact of up to 697,000 (11.5%) infections prevented could be achieved by targeting age cohorts of highest incidence. Economic evaluation indicates that, if treatment scale-up was achieved, vaccination could be cost-effective at a total cost of less than $385 and $62 per 10-year series (cost-effectiveness thresholds of $5,691 and $750).ConclusionsWhile a partially effective, rapidly waning vaccine could help to prevent HIV infections, it will not eliminate HIV as a public health priority in sub-Saharan Africa. Vaccination is expected to be most effective under targeted delivery to age groups of highest HIV incidence. Awaiting results of trial, the introduction of vaccination should go in parallel with continued innovation in HIV prevention, including studies to determine the costs of delivery and feasibility and further research into products with greater efficacy and durability.

The primary prevention of anxiety disorders

2020 ◽  
pp. 948-960
Author(s):  
Aliza Werner-Seidler ◽  
Jennifer L. Hudson ◽  
Helen Christensen
Keyword(s):  
Anxiety Disorder ◽  
Primary Prevention ◽  
Scale Up ◽  
Population Level ◽  
Implementation Barriers ◽  
Cognitive Behavioural ◽  
Post Test ◽  
Prevention Programmes ◽  
Programme Content ◽  
The Impact

This chapter describes the nature of primary prevention of anxiety and reports on evidence for its effectiveness. The chapter first defines prevention before reporting results of a systematic review of randomized controlled trials designed to prevent anxiety. A review of existing trials and associated effect sizes suggests that prevention programmes can be effective in preventing anxiety disorder incidence and symptoms in multiple settings (schools, workplaces, community) across the lifespan. The median effect size at post-test across all studies was 0.21, and 0.25 specifically for cognitive behavioural prevention programmes. Key elements common to prevention programmes are then discussed, including a consideration of programme content and personnel delivering the intervention. Key implementation barriers are raised, together with suggestions for how these might be overcome in order to scale up and offer prevention at a population level. The chapter concludes with a consideration of the impact these programmes could have on anxiety disorder incidence.

scholarly journals Using Google Earth™ and Geographical Information System data as method to delineate sample domains for an urban household surveys: the case of Maroua (Far North Region-Cameroon)

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ronald R. B. Ngom Vougat ◽  
Steven Chouto ◽  
Sylvain Aoudou Doua ◽  
Rebecca Garabed ◽  
André Zoli Pagnah ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Google Earth ◽  
Geographical Information ◽  
Gps Tracking ◽  
Low Incomes ◽  
Global Positioning ◽  
System Data ◽  
The One ◽  
Time Required

Abstract Background Getting a random household sample during a survey can be expensive and very difficult especially in urban area and non-specialist. This study aimed to test an alternative method using freely available aerial imagery. Methods A gridded map and random selection method was used to select households for interviews. A hundred numbered of points were put along the edges of an updated map of Maroua. Then two numbers were randomly draw at a time and a line was drawn between those two numbers. A lot of different kinds of shapes of different sizes obtained were numbered. Ten shapes were randomly draw and the one selected were considered as ‘neighbourhoods’. A grid of 30 m × 30 m was drawn over each and then numbered. 202 grids considered here as households were randomly selected from the ten neighbourhoods for interviews. Results Out of 202 households visited, only 4 were found to be something other than a house. In addition, 30 sampled households (14.85%) were abandoned or the occupants had relocated elsewhere. This method resulted in an accuracy level of 72%, its advantage is the ability to generate efficient random sample at relatively low cost as well the time required. Conclusions The method proposed in this study was efficient and cost-effective when compared to the infield generation of a household inventory or Global Positioning System (GPS) tracking of households. It can then be used by researchers in low-incomes countries where funding for research is a challenge. However, this method needs to train the investigators on how to use the GPS.

scholarly journals Challenges in estimating the impact of vaccination with sparse data

2018 ◽  
Author(s):  
Kayoko Shioda ◽  
Cynthia Schuck-Paim ◽  
Robert J. Taylor ◽  
Roger Lustig ◽  
Lone Simonsen ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Simulation Analysis ◽  
Principal Component ◽  
Population Level ◽  
Series Data ◽  
Synthetic Control ◽  
Vaccine Impact ◽  
Pca Method ◽  
The Impact

ABSTRACTBackgroundThe synthetic control (SC) model is a powerful tool to quantify the population-level impact of vaccines, because it can adjust for trends unrelated to vaccination using a composite of control diseases. Because vaccine impact studies are often conducted using smaller subnational datasets, we evaluated the performance of SC models with sparse time series data. To obtain more robust estimates of vaccine effects from noisy time series, we proposed a possible alternative approach, “STL+PCA” method (seasonal-trend decomposition plus principal component analysis), which first extracts smoothed trends from the control time series and uses them to adjust the outcome.MethodsUsing both the SC and STL+PCA models, we estimated the impact of 10-valent pneumococcal conjugate vaccine (PCV10) on pneumonia hospitalizations among cases <12 months and 80+ years of age during 2004-2014 at the subnational level in Brazil. The performance of these models was also compared using simulation analyses.ResultsThe SC model was able to adjust for trends unrelated to PCV10 in larger states but not in smaller states. The simulation analysis confirmed that the SC model failed to select an appropriate set of control diseases when the time series were sparse and noisy, thereby generating biased estimates of the impact of vaccination when secular trends were present. The STL+PCA approach decreased bias in the estimates for smaller populations.ConclusionsEstimates from the SC model might be biased when data are sparse. The STL+PCA model provides more accurate evaluations of vaccine impact in smaller populations.

scholarly journals Downsizing of contact tracing during COVID-19 vaccine roll-out

2021 ◽  
Author(s):  
Maria M Martignoni ◽  
Joshua Renault ◽  
Joseph Baafi ◽  
Amy Hurford
Keyword(s):  
Exponential Growth ◽  
Cost Effective ◽  
Quantitative Information ◽  
Vaccination Status ◽  
Outbreak Detection ◽  
Contact Tracing ◽  
Epidemic Spread ◽  
Social Distancing ◽  
The Impact ◽  
Roll Out

Contact tracing is a key component of successful management of COVID-19. Contacts of infected individuals are asked to quarantine, which can significantly slow down (or prevent) community spread. Contact tracing is particularly effective when infections are detected quickly (e.g., through rapid testing), when contacts are traced with high probability, when the initial number of cases is low, and when social distancing and border restrictions are in place. However, the magnitude of the individual contribution of these factors in reducing epidemic spread and the impact of vaccination in determining contact tracing outputs is not fully understood. We present a delayed differential equation model to investigate how vaccine roll-out and the relaxation of social distancing requirements affect contact tracing practises. We provide an analytical criteria to determine the minimal contact tracing efficiency (defined as the the probability of identifying and quarantining contacts of symptomatic individuals) required to keep an outbreak under control, with respect to the contact rate and vaccination status of the population. Additionally, we consider how delays in outbreak detection and increased case importation rates affect the number of contacts to be traced daily. We show that in vaccinated communities a lower contact tracing efficiency is required to avoid uncontrolled epidemic spread, and delayed outbreak detection and relaxation of border restrictions do not lead to a significantly higher risk of overwhelming contact tracing. We find that investing in testing programs, rather than increasing the contact tracing capacity, has a larger impact in determining whether an outbreak will be controllable. This is because early detection activates contact tracing, which will slow, and eventually reverse exponential growth, while the contact tracing capacity is a threshold that will easily become overwhelmed if exponential growth is not curbed. Finally, we evaluate quarantine effectiveness during vaccine roll-out, by considering the proportion of people that will develop an infection while in isolation in relation to the vaccination status of the population and for different viral variants. We show that quarantine effectiveness decreases with increasing proportion of fully vaccinated individuals, and increases in the presence of more transmissible variants. These results suggest that a cost-effective approach during vaccine roll-out is to establish different quarantine rules for vaccinated and unvaccinated individuals, where rules should depend on viral transmissibility. Altogether, our study provides quantitative information for contact tracing downsizing during vaccine roll-out, to guide COVID-19 exit strategies.

scholarly journals Trend analysis of tuberculosis case notifications with scale-up of antiretroviral therapy and roll-out of isoniazid preventive therapy in Zimbabwe, 2000–2018

BMJ Open ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. e034721
Author(s):  
Kudakwashe C Takarinda ◽  
Anthony D Harries ◽  
Tsitsi Mutasa-Apollo ◽  
Charles Sandy ◽  
Regis C Choto ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Scale Up ◽  
Population Level ◽  
Preventive Therapy ◽  
Isoniazid Preventive Therapy ◽  
People Living With Hiv ◽  
National Data ◽  
Tuberculosis Case ◽  
Case Notification ◽  
Roll Out

ObjectivesAntiretroviral therapy (ART) and isoniazid preventive therapy (IPT) are known to have a tuberculosis (TB) protective effect at the individual level among people living with HIV (PLHIV). In Zimbabwe where TB is driven by HIV infection, we have assessed whether there is a population-level association between IPT and ART scale-up and annual TB case notification rates (CNRs) from 2000 to 2018.DesignEcological study using aggregate national data.SettingAnnual aggregate national data on TB case notification rates (stratified by TB category and type of disease), numbers (and proportions) of PLHIV in ART care and of these, numbers (and proportions) ever commenced on IPT.ResultsART coverage in the public sector increased from <1% (8400 PLHIV) in 2004 to ~88% (>1.1 million PLHIV patients) by December 2018, while IPT coverage among PLHIV in ART care increased from <1% (98 PLHIV) in 2012 to ~33% (373 917 PLHIV) by December 2018. These HIV-related interventions were associated with significant declines in TB CNRs: between the highest CNR prior to national roll-out of ART (in 2004) to the lowest recorded CNR after national IPT roll-out from 2012, these were (1) for all TB case (510 to 173 cases/100 000 population; 66% decline, p<0.001); (2) for those with new TB (501 to 159 cases/100 000 population; 68% decline, p<0.001) and (3) for those with new clinically diagnosed PTB (284 to 63 cases/100 000 population; 77.8% decline, p<0.001).ConclusionsThis study shows the population-level impact of the continued scale-up of ART among PLHIV and the national roll-out of IPT among those in ART care in reducing TB, particularly clinically diagnosed TB which is largely associated with HIV. There are further opportunities for continued mitigation of TB with increasing coverage of ART and in particular IPT which still has a low coverage.

scholarly journals Revisiting: “A pre-post study of a multi-country scale up of resuscitation training of facility birth attendants: does helping babies breathe training save lives?”

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sara Berkelhamer ◽  
Nalini Singhal
Keyword(s):  
Neonatal Mortality ◽  
Low Cost ◽  
Scale Up ◽  
Neonatal Resuscitation ◽  
Population Level ◽  
Helping Babies Breathe ◽  
Birth Attendants ◽  
Resuscitation Training ◽  
Facility Birth ◽  
The Impact

Abstract Background Helping Babies Breathe (HBB) is a low cost, skills-based neonatal resuscitation education program designed specifically for use in low resource settings. Studies from Tanzania, India and Nepal have demonstrated that HBB training results in decreased rates of fresh still birth and/or neonatal mortality. However, less is known regarding the impact of training on neonatal mortality at a population level. Bellad et al. utilized (BMC Pregnancy Childbirth. 2016;16 (1):222) utilized population based registries to evaluate outcomes before and after training of facility birth attendants. Their study entitled “A pre-post study of a multi-country scale up of resuscitation training of facility birth attendants: Does Helping Babies Breathe training save lives?” suggested facility based training was not associated with consistent improvements in neonatal mortality on a population level. Discussion Combining outcomes from three diverse settings may have under-estimated the impact of HBB training. We remain concerned that the modest benefits observed in the Kenyan site were lost with compiling of data. Summary The statement that HBB “was not associated with consistent improvements in mortality” may lead to the mistaken conclusion that improvements in neonatal mortality were not seen, when in fact, they were in selected cohorts. With numerous studies demonstrating potential for reduced neonatal mortality as a result of HBB training, we encourage interpretation of these findings in the context of local care.

scholarly journals Health benefits and costs of weight-loss dietary counselling by nurses in primary care: a cost-effectiveness analysis

2019 ◽  
Vol 23 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Christine L Cleghorn ◽  
Nick Wilson ◽  
Nisha Nair ◽  
Giorgi Kvizhinadze ◽  
Nhung Nghiem ◽  
...  
Keyword(s):  
Primary Care ◽  
Weight Loss ◽  
Cost Effectiveness ◽  
Population Level ◽  
Cost Effective ◽  
Uncertainty Interval ◽  
Dietary Counselling ◽  
Life Years ◽  
Per Capita ◽  
The Impact

AbstractObjective:We aimed to estimate the cost-effectiveness of brief weight-loss counselling by dietitian-trained practice nurses, in a high-income-country case study.Design:A literature search of the impact of dietary counselling on BMI was performed to source the ‘best’ effect size for use in modelling. This was combined with multiple other input parameters (e.g. epidemiological and cost parameters for obesity-related diseases, likely uptake of counselling) in an established multistate life-table model with fourteen parallel BMI-related disease life tables using a 3 % discount rate.Setting:New Zealand (NZ).Participants:We calculated quality-adjusted life-years (QALY) gained and health-system costs over the remainder of the lifespan of the NZ population alive in 2011 (n 4·4 million).Results:Counselling was estimated to result in an increase of 250 QALY (95 % uncertainty interval −70, 560 QALY) over the population’s lifetime. The incremental cost-effectiveness ratio was 2011 $NZ 138 200 per QALY gained (2018 $US 102 700). Per capita QALY gains were higher for Māori (Indigenous population) than for non-Māori, but were still not cost-effective. If willingness-to-pay was set to the level of gross domestic product per capita per QALY gained (i.e. 2011 $NZ 45 000 or 2018 $US 33 400), the probability that the intervention would be cost-effective was 2 %.Conclusions:The study provides modelling-level evidence that brief dietary counselling for weight loss in primary care generates relatively small health gains at the population level and is unlikely to be cost-effective.

A Study of a New Generation of Multi-Functional Aluminium Alloys for the Power Industry

2011 ◽  
Vol 690 ◽  
pp. 439-442 ◽  
Author(s):  
Beata Smyrak ◽  
Tadeusz Knych ◽  
Andrzej Mamala ◽  
Piotr Uliasz ◽  
Michał Jabłoński
Keyword(s):  
Aluminium Alloys ◽  
Power Transmission ◽  
Electrical Power ◽  
Cost Effective ◽  
Present Condition ◽  
Pure Aluminium ◽  
The One ◽  
Manufacturing Technologies ◽  
New Generation ◽  
The Impact

This paper discusses the most current issues of overhead power transmission relative to the development of new conductive materials with unconventional technological and operational qualities. The present condition is based on the one hand on the traditional aluminium-steel conductors with their numerous weaknesses, and on the other hand on state of the art design solutions employing self-supporting, highly-conductive, and thermally and rheologically resistant aluminium alloys. A gap exists between pure aluminium-based conductors which are no longer sufficient and conductors made of precipitation hardened aluminium alloys, which even though they allow to achieve perfect properties, they are not sufficiently cost-effective as for their complex manufacturing technologies. For these reasons, light and sufficiently strong materials based on aluminium are needed, which enable simplified technologies for processing into conductors. Non-precipitation hardened aluminium alloys with such alloy additives as Fe, Si, Cu, Mg, Ti, B, and rare earth metals are preferred in this area. An appropriate composition of these elements, as well as manufacturing and alloy production technology (casting, rolling and drawing) create potential opportunities to obtain wires and conductors with application properties required by electrical power engineering. This paper thoroughly analyses the impact of various elements on the formation of mechanical and electrical properties of aluminium alloys.

scholarly journals Ionotropic Gelation of Chitosan for Next-Generation Composite Proton Conducting Flat Structures

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1632 ◽  
Author(s):  
Patrizia Bocchetta
Keyword(s):  
Fuel Cell ◽  
Cost Effective ◽  
Composite Membranes ◽  
Proton Conducting ◽  
Ionotropic Gelation ◽  
Flat Structures ◽  
The One ◽  
Key Aspects ◽  
The Impact

(1) Background: Ionotropic gelation of cost-effective and eco-friendly biopolymer chitosan (Chit) is a novel and promising approach to the one-step synthesis of proton-conducting fuel cell bio-membranes.The method discovered by the author in 2011 and subsequently drowned among very few papers. This work aimed to relaunch this method through clear and effective communication of new unpublished results emphasizing the key aspects of this topic for successful dissemination of the results and significant future developments. (2) Methods and results: The mechanism of in-situ ionotropic gelation of Chit on an alumina substrate by phosphotungtate anions (PWA3−) was discussed and analyzed. The study sheds light on the effect of prolonged post-treatment in phosphotungstic acid (PWA) solution on the obtained chitosan/phosphotungstate (Chit-PWA) flat structures. Methods used included combined structural (XRD), thermal-gravimetric (DTG), electrochemical (in-situ EIS), compositional (EDX),morphological analysis (SEM), as well as the performances in a low temperature H2/O2 fuel cell(4) Conclusions: This contribution discloses novel possibilities aimed at increasing the impact of ionotropic gelation of chitosan on the scientific community working on the synthesis of novel proton conductive bio-composite membranes and structures.

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