Fractional-dose inactivated poliovirus vaccine, India.

In 2016, the World Health Organization (WHO) announced a global shortage of inactivated poliovirus vaccine that was expected to last until 2020 at least. In response, WHO's Strategic Advisory Group of Experts on Immunization recommended that countries consider a strategic shift to fractional-dose inactivated poliovirus vaccine, which involves a new dosing schedule (i.e. administered at 6 and 14 weeks of age) and has a different mode of delivery than full-dose inactivated poliovirus vaccine (i.e. intradermal rather than intramuscular). Introduction of fractional-dosing requires careful planning and management to ensure adequate vaccine supplies, to prevent wastage, to provide training for health workers, and to ensure accurate record-keeping. In early 2016, given the global vaccine shortage and a limited supply from domestic manufacturers, India's Expert Advisory Group on polio recommended the staggered introduction of fractional-dosing. India was the first country to introduce fractional-dose inactivated poliovirus vaccine into routine immunization, initially in eight states in 2016. Following a rapid assessment of its initial implementation, fractional-dosing was extended and, by June 2017, all Indian states were covered. Here we summarize India's experience with the introduction, discuss the challenges faced and the strategies used to address them, and report on the outcomes achieved. We also describe the lessons learnt, especially managing vaccine supplies and wastage, monitoring and supervision, and training needs. As the use of fractional-dose inactivated poliovirus vaccine is dose-sparing and reduces the cost of the immunization programme, it will remain an important part of India's long-term strategy for polio vaccination.

En 2016, l'Organisation mondiale de la Santé (OMS) a annoncé une pénurie mondiale du vaccin antipoliomyélitique inactivé, prévue pour durer jusqu'à 2020 au minimum. Face à cette situation, le Groupe stratégique consultatif d'experts sur la vaccination a recommandé aux pays d'envisager un changement de stratégie afin de privilégier l'utilisation du vaccin antipoliomyélitique inactivé en doses fractionnées, ce qui implique un nouveau calendrier de vaccination (administration du vaccin à l'âge de 6 et de 14 semaines) et un mode d'administration différent de celui du vaccin antipoliomyélitique inactivé en dose complète (par voie intradermique et non pas par voie intramusculaire). L'introduction d'une vaccination en doses fractionnées exige de la rigueur en matière de planification et de gestion, afin de garantir des stocks de vaccins suffisants, d'éviter les gaspillages, de former les agents de santé et d'assurer une tenue précise des dossiers médicaux. Début 2016, du fait de la pénurie mondiale du vaccin et d'un approvisionnement limité par les fabricants nationaux, le Groupe consultatif d'experts de l'Inde sur l'éradication de la poliomyélite a recommandé d'introduire progressivement les doses fractionnées. Si bien que l'Inde est le premier pays à avoir introduit le vaccin antipoliomyélitique inactivé en doses fractionnées dans le calendrier de vaccination systématique, d'abord dans huit États en 2016. Après une rapide évaluation de cette mise en œuvre initiale, l'utilisation des doses fractionnées s'est étendue, pour finalement être effective dans tous les États indiens en juin 2017. Dans cet article, nous récapitulons l'expérience de l'Inde à ce sujet, nous évoquons les défis rencontrés et les stratégies employées pour les surmonter ainsi que les résultats obtenus. Nous décrivons également les enseignements tirés de cette expérience, notamment en matière de gestion des stocks de vaccins, de prévention des gaspillages, de suivi et de supervision, mais aussi concernant les besoins en formation. Étant donné que l'utilisation de doses fractionnées du vaccin antipoliomyélitique inactivé permet d'économiser des doses vaccinales et de réduire le coût du programme de vaccination, cela restera un élément essentiel dans la stratégie à long terme de l'Inde en matière de vaccination contre la poliomyélite.

En 2016, la Organización Mundial de la Salud (OMS) anunció una escasez mundial de vacunas inactivadas del poliovirus que se esperaba que se prolongara al menos hasta 2020. En respuesta, el Grupo de asesoramiento estratégico de expertos en inmunización de la OMS recomendó que los países consideraran la posibilidad de un cambio estratégico hacia una vacuna inactivada del poliovirus de dosis fraccionada, que incluye un nuevo esquema de dosificación (es decir, administrada a las seis y a las catorce semanas de edad) y que tiene un modo de administración diferente al de la vacuna inactivada del poliovirus de dosis completa (es decir, intradérmica y no intramuscular). La introducción de la dosis fraccionada requiere una planificación y una gestión minuciosas para garantizar el suministro adecuado de las vacunas, evitar el despilfarro, formar a los trabajadores sanitarios y garantizar el mantenimiento de registros precisos. A principios de 2016, dada la escasez mundial de vacunas y el limitado suministro de los fabricantes nacionales, el Grupo de asesoramiento experto sobre la polio de la India recomendó la introducción escalonada de dosis fraccionadas. La India fue el primer país en introducir la vacuna inactivada del poliovirus de dosis fraccionada en la inmunización sistemática, inicialmente en ocho estados en 2016. Tras una rápida evaluación de la aplicación inicial, se amplió la dosificación fraccionada y, para junio de 2017, se cubrieron todos los estados de la India. En este documento se resume la experiencia de la India con la introducción, se examinan los problemas encontrados y las estrategias utilizadas para resolverlos y se informa sobre los resultados alcanzados. También se describen las lecciones aprendidas, especialmente en lo que se refiere a la gestión de los suministros de vacunas y el desperdicio, el seguimiento y la supervisión, y las necesidades de formación. Dado que el uso de la vacuna inactivada del poliovirus de dosis fraccionada ahorra dosis y reduce el coste del programa de inmunización, seguirá siendo una parte importante de la estrategia a largo plazo de la India para la vacunación contra la polio.

Intradermal Administration of Fractional Doses of Inactivated Poliovirus Vaccine: A Dose-Sparing Option for Polio Immunization.

A fractional dose of inactivated poliovirus vaccine (fIPV) administered by the intradermal route delivers one fifth of the full vaccine dose administered by the intramuscular route and offers a potential dose-sparing strategy to stretch the limited global IPV supply while further improving population immunity. Multiple studies have assessed immunogenicity of intradermal fIPV compared with the full intramuscular dose and demonstrated encouraging results. Novel intradermal devices, including intradermal adapters and disposable-syringe jet injectors, have also been developed and evaluated as alternatives to traditional Bacillus Calmette-Guérin needles and syringes for the administration of fIPV. Initial experience in India, Pakistan, and Sri Lanka suggests that it is operationally feasible to implement fIPV vaccination on a large scale. Given the available scientific data and operational feasibility shown in early-adopter countries, countries are encouraged to consider introducing a fIPV strategy into their routine immunization and supplementary immunization activities.

Improved DNA Vaccine Delivery with Needle-Free Injection Systems.

DNA vaccines have inherent advantages compared to other vaccine types, including safety, rapid design and construction, ease and speed to manufacture, and thermostability. However, a major drawback of candidate DNA vaccines delivered by needle and syringe is the poor immunogenicity associated with inefficient cellular uptake of the DNA. This uptake is essential because the target vaccine antigen is produced within cells and then presented to the immune system. Multiple techniques have been employed to boost the immunogenicity and protective efficacy of DNA vaccines, including physical delivery methods, molecular and traditional adjuvants, and genetic sequence enhancements. Needle-free injection systems (NFIS) are an attractive alternative due to the induction of potent immunogenicity, enhanced protective efficacy, and elimination of needles. These advantages led to a milestone achievement in the field with the approval for Restricted Use in Emergency Situation of a DNA vaccine against COVID-19, delivered exclusively with NFIS. In this review, we discuss physical delivery methods for DNA vaccines with an emphasis on commercially available NFIS and their resulting safety, immunogenic effectiveness, and protective efficacy. As is discussed, prophylactic DNA vaccines delivered by NFIS tend to induce non-inferior immunogenicity to electroporation and enhanced responses compared to needle and syringe.

Assessing the risk of a clinically significant infection from a Microneedle Array Patch (MAP) product.

Microneedle Array Patches (MAPs) are an emerging dosage form that creates transient micron-sized disruptions in the outermost physical skin barrier, the stratum corneum, to facilitate delivery of active pharmaceutical ingredients to the underlying tissue. Numerous MAP products are proposed and there is significant clinical potential in priority areas such as vaccination. However, since their inception scientists have hypothesized about the risk of a clinically significant MAP-induced infection. Safety data from two major Phase 3 clinical trials involving hundreds of participants, who in total received tens of thousands of MAP applications, does not identify any clinically significant infections. However, the incumbent data set is not extensive enough to make definitive generalizable conclusions. A comprehensive assessment of the infection risk is therefore advised for MAP products, and this should be informed by clinical and pre-clinical data, theoretical analysis and informed opinions. In this article, a group of key stakeholders identify some of the key product- and patient-specific factors that may contribute to the risk of infection from a MAP product and provide expert opinions in the context of guidance from regulatory authorities. Considerations that are particularly pertinent to the MAP dosage form include the specifications of the finished product (e.g. microbial specification), it's design features, the setting for administration, the skill of the administrator, the anatomical application site, the target population and the clinical context. These factors, and others discussed in this article, provide a platform for the development of MAP risk assessments and a stimulus for early and open dialogue between developers, regulatory authorities and other key stakeholders, to expedite and promote development of safe and effective MAP products.

Strategies for vaccine-product innovation: Creating an enabling environment for product development to uptake in low- and middle-income countries.

Vaccine-product innovations that address barriers to immunization are urgently needed to achieve equitable vaccine coverage, as articulated in the new Immunization Agenda 2030 and the Gavi 5.0 strategy. In 2020, the Vaccine Innovation Prioritisation Strategy (VIPS) prioritized three innovations, namely microarray patches (MAPs), heat-stable and controlled-temperature chain (CTC) enabled liquid vaccine formulations and barcodes on primary packaging. These innovations were prioritized based on the priority immunization barriers that they may help overcome in resource constrained contexts, as well as by considering their potential impact on health, coverage and equity, safety, economic costs and their technical readiness and commercial feasibility. VIPS is now working to accelerate the development and lay the foundation for future uptake of the three priority vaccine-product innovations, with the long term-goal to ensure equitable vaccine coverage and increased impact of vaccines in low- and middle- income countries. To inform our strategic planning, we analyzed four commercially available vaccine product-innovations and conducted interviews with individuals from 17 immunization organizations, and/or independent immunization experts. The findings are synthesized into an 'innovation conundrum' that describes the challenges encountered in developing vaccine-product innovations and a vaccine-product innovation 'theory of change', which highlights actions that should be undertaken in parallel to product development to incentivize sustainable investment and prepare the pathway for uptake and impact.

Potential use of microarray patches for vaccine delivery in low- and middle- income countries.

Microarray patches (MAPs), also referred to as microneedle patches, are a novel methodology that have the potential to overcome barriers to vaccine delivery in low- and middle-income countries (LMICs), and transform the way that vaccines are delivered within immunization programs. The World Health Organization's Initiative for Vaccine Research and its partners are working to understand how MAPs could ease vaccine delivery and increase equitable access to vaccines in LMICs. Global stakeholders have been engaged to evaluate technical, economic, and programmatic challenges; to validate assumptions where possible; and to propose areas of focus to facilitate future vaccine-MAP product development. This report summarizes those learnings.

Evaluating the cost per child vaccinated with full versus fractional-dose inactivated poliovirus vaccine.

INTRODUCTION: Inactivated poliovirus vaccine (IPV) shortages and evidence of improved immunogenicity of two intradermal (ID) fractional IPV (fIPV) doses compared with one full intramuscular dose led to recommendations for fIPV delivery. To provide evidence on the economics of fIPV, we estimated the cost per child vaccinated using full-dose IPV compared with fIPV in routine and campaign settings. We evaluated the impact on costs of alternative devices facilitating ID administration, vaccine vial sizes, and prices. METHODS: We used an Excel-based model to estimate the commodity and delivery costs for providing IPV. Commodity costs included vaccine price per dose adjusted for wastage, prices for vaccine administration devices, and safety boxes. Delivery costs included storage costs at each level of the supply chain, transport costs for commodities between levels, and human resource costs for vaccine administration. Model inputs were obtained from various databases and published literature. All costs are reported in 2018 US dollars. RESULTS: In both campaign and routine settings, fIPV had a lower cost per child vaccinated than full dosing, despite the assumed higher vaccine wastage with fIPV in routine settings, and even when novel ID administration devices were used. In routine settings, costs per child fully vaccinated with fractional doses were 15% to 48% lower than those with full-dose delivery across different vial sizes. The cost per child vaccinated ranged from $1.84 to $2.65 for fractional doses, depending on the administration device, compared with $3.57 for full dose, when using 5-dose vials. The magnitude of cost reductions with fIPV relative to full-dose IPV was largest with smaller vial sizes and higher vaccine price. CONCLUSION: Adopting fIPV can reduce costs per child vaccinated compared with using full doses, especially as IPV prices increase in the short term and more so when two full doses could be recommended in the future.

Design, Formulation, and Evaluation of Novel Dissolving Microarray Patches Containing Rilpivirine for Intravaginal Delivery.

Antiretroviral (ARV) drugs have, for many years, been studied and administered in the prevention and treatment of human immunodeficiency virus (HIV). Intramuscular (IM) injection of long acting (LA) ARVs are in clinical development, but injectable formulations require regular access to healthcare facilities and disposal facilities for sharps. The development of a discrete, self-administered, and self-disabling vehicle to deliver ARVs could obviate these issues. This study describes the formulation, mechanical characterization, and in vivo evaluation of dissolving microarray patches (MAPs) containing a LA nanosuspension of the ARV, rilpivirine (RPV, RPV LA), for vaginal delivery. This is the first study to apply MAPs into vaginal tissue. The RPV LA MAPs penetrate ex vivo skin and a synthetic vaginal skin model and withstand the effects of potential dragging motion across synthetic vaginal epithelium. In in vivo studies, the mean plasma concentration of RPV in rats at the 56 day endpoint (116.5 ng mL-1 ) is comparable to that achieved in the IM control cohort (118.9 ng mL-1 ). RPV is detected systemically, in lymph and vaginal tissue, indicating the potential to deliver RPV LA to primary sites of viral challenge and replication. This innovative research has future potential for patients and healthcare workers, particularly in low-resource settings.

Clinical study of safety and immunogenicity of pentavalent DTP-HB-Hib vaccine administered by disposable-syringe jet injector in India.

INTRODUCTION: We conducted a randomized, observer-blind, non-inferiority, parallel-group clinical study of diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b conjugate (pentavalent) vaccination of infants in India. Goals were to determine whether the seropositivity rate after vaccination via disposable-syringe jet injector (DSJI) was non-inferior to that via needle and syringe (N-S), and to compare the safety of vaccination by the two methods. METHODS: Healthy children received a three-dose series of vaccine intramuscularly by DSJI or N-S beginning at 6-8 weeks of age. Immunoglobulin G antibody levels were measured by ELISA at 4-6 weeks after the third dose. The main secondary endpoint was safety, measured as injection site and systemic reactions. DISCUSSION: The study was stopped early out of caution beyond that specified in the protocol stopping criteria, after the Data Safety Committee noted a higher frequency of injection site reactions, especially moderate and severe, in the DSJI group. As a result, 128 subjects-DSJI group 61; N-S group 67-completed the study, rather than the 340 planned, and the study was not sufficiently powered to compare immunogenicity endpoints for the groups. Descriptive statistics indicate that seropositivity induced by vaccination with the DSJI was similar to that of N-S for all five antigens. Pentavalent vaccine includes whole-cell pertussis vaccine and an aluminum adjuvant, which may have contributed to the higher number of local reactions with the DSJI. The reactions caused no serious or long-term sequelae, and may be more acceptable in other populations or circumstances.US National Institutes of Health clinical trials identifier: NCT02409095.

Immunogenicity and safety of measles-mumps-rubella vaccine delivered by disposable-syringe jet injector in India: A randomized, parallel group, non-inferiority trial.

BACKGROUND: We conducted a randomized, non-inferiority, clinical study of MMR vaccine by a disposable-syringe jet injector (DSJI) in toddlers in India in comparison with the conventional administration. METHODS: MMR vaccine was administered subcutaneously by DSJI or needle-syringe (N-S) to toddlers (15-18 months) who had received a measles vaccine at 9 months. Seropositivity to measles, mumps, and rubella serum IgG antibodies was assessed 35 days after vaccination. Non-inferiority was concluded if the upper limit of the 95% CI for the difference in the percent of seropositive between groups was less than 10%. Solicited reactions were collected for 14 days after vaccination by using structured diaries. RESULTS: In each study group, 170 subjects received MMR vaccine. On day 35, seropositivity for measles was 97.5% [95% CI (93.8%, 99.3%)] in the DSJI group and 98.7% [95% CI (95.5%, 99.8%)] in the N-S group; for mumps, 98.8% [95% CI (95.6%, 99.8%)] and 98.7% [95% CI (95.5%, 99.8%)]; and for rubella, 98.8% [95% CI (95.6%, 99.8%)] and 100% [95% CI (97.7%, 100.0%)]; none of the differences were significant. The day 35 post-vaccination GMTs in DSJI and N-S groups were measles: 5.48 IU/ml [95% CI (3.71, 8.11)] and 5.94 IU/ml [95% CI (3.92, 9.01)], mumps: 3.83 ISR [95% CI (3.53, 4.14)] and 3.66 ISR [95% CI (3.39, 3.95)] and rubella: 95.27 IU/ml [95% CI (70.39, 128.95)] and 107.06 IU/ml [95% CI (79.02, 145.06)]; none of the differences were significant. The DSJI group reported 173 solicited local reactions and the N-S group reported 112; most were mild grade. Of the total of 156 solicited systemic adverse events, most were mild, and incidence between the two groups was similar. CONCLUSIONS: MMR vaccination via DSJI is as immunogenic as vaccination by N-S. Safety profile of DSJI method is similar to N-S except for injection site reactions which are more with DSJI and are well-tolerated. Registration US National Institutes of Health clinical trials identifier - NCT02253407. Clinical trial registry of India identifier - CTRI/2013/05/003702.

Transdermal delivery of vitamin K using dissolving microneedles for the prevention of vitamin K deficiency bleeding.

Vitamin K deficiency within neonates can result in vitamin K deficiency bleeding. Ensuring that newborns receive vitamin K is particularly critical in places where access to health care and blood products and transfusions is limited. The World Health Organization recommends that newborns receive a 1 mg intramuscular injection of vitamin K at birth. Evidence from multiple surveillance studies shows that the introduction of vitamin K prophylaxis reduces the incidence of vitamin K deficiency bleeding. Despite these recommendations, coverage of vitamin K prophylactic treatment in low-resource settings is limited. An intramuscular injection is the most common method of vitamin K administration in neonates. In low- and middle-income countries, needle sharing may occur, which may result in the spread of bloodborne diseases. The objective of our study was to investigate the manufacture of microneedles for the delivery of vitamin K. Following microneedle fabrication, we performed insertion studies to assess the microneedle's mechanical properties. Results indicate that vitamin K in a microneedle array was successfully delivered in vitro across neonatal porcine skin with 1.80 ±â€¯0.08 mg delivered over 24 h. Therefore, this initial study shows that microneedles do have the potential to prevent vitamin K deficiency bleeding. Future work will assess delivery of vitamin K in microneedle array in vivo.

Cost of goods sold and total cost of delivery for oral and parenteral vaccine packaging formats.

Despite limitations of glass packaging for vaccines, the industry has been slow to implement alternative formats. Polymer containers may address many of these limitations, such as breakage and delamination. However, the ability of polymer containers to achieve cost of goods sold (COGS) and total cost of delivery (TCOD) competitive with that of glass containers is unclear, especially for cost-sensitive low- and lower-middle-income countries. COGS and TCOD models for oral and parenteral vaccine packaging formats were developed based on information from subject matter experts, published literature, and Kenya's comprehensive multiyear plan for immunization. Rotavirus and inactivated poliovirus vaccines (IPV) were used as representative examples of oral and parenteral vaccines, respectively. Packaging technologies evaluated included glass vials, blow-fill-seal (BFS) containers, preformed polymer containers, and compact prefilled auto-disable (CPAD) devices in both BFS and preformed formats. For oral vaccine packaging, BFS multi-monodose (MMD) ampoules were the least expensive format, with a COGS of $0.12 per dose. In comparison, oral single-dose glass vials had a COGS of $0.40. BFS MMD ampoules had the lowest TCOD of oral vaccine containers at $1.19 per dose delivered, and ten-dose glass vials had a TCOD of $1.61 per dose delivered. For parenteral vaccines, the lowest COGS was achieved with ten-dose glass vials at $0.22 per dose. In contrast, preformed CPAD devices had the highest COGS at $0.60 per dose. Ten-dose glass vials achieved the lowest TCOD of the parenteral vaccine formats at $1.56 per dose delivered. Of the polymer containers for parenteral vaccines, BFS MMD ampoules achieved the lowest TCOD at $1.89 per dose delivered, whereas preformed CPAD devices remained the most expensive format, at $2.25 per dose delivered. Given their potential to address the limitations of glass and reduce COGS and TCOD, polymer containers deserve further consideration as alternative approaches for vaccine packaging.

Design, formulation and evaluation of novel dissolving microarray patches containing a long-acting rilpivirine nanosuspension.

One means of combating the spread of human immunodeficiency virus (HIV) is through the delivery of long-acting, antiretroviral (ARV) drugs for prevention and treatment. The development of a discreet, self-administered and self-disabling delivery vehicle to deliver such ARV drugs could obviate compliance issues with daily oral regimens. Alternatives in development, such as long-acting intramuscular (IM) injections, require regular access to health care facilities and disposal facilities for sharps. Consequently, this proof of concept study was developed to evaluate the use of dissolving microarray patches (MAPs) containing a long-acting (LA) nanosuspension of the candidate ARV drug, rilpivirine (RPV). MAPs were mechanically strong and penetrated skin in vitro, delivering RPV intradermally. In in vivo studies, the mean plasma concentration of RPV in rats (431 ng/ml at the Day 7 time point) was approximately ten-fold greater than the trough concentration observed after a single-dose in previous clinical studies. These results are the first to indicate, by the determination of relative exposures between IM and MAP administration, that larger multi-array dissolving MAPs could potentially be used to effectively deliver human doses of RPV LA. Importantly, RPV was also detected in the lymph nodes, indicating the potential to deliver this ARV agent into one of the primary sites of HIV replication over extended durations. These MAPs could potentially improve patient acceptability and adherence to HIV prevention and treatment regimens and combat instances of needle-stick injury and the transmission of blood-borne diseases, which would have far-reaching benefits, particularly to those in the developing world.

Exploring new packaging and delivery options for the immunization supply chain.

A variety of vaccine packaging and delivery technologies may benefit the immunization supply chain. These include alternative primary packaging, such as blow-fill-seal polymer containers, and novel delivery technologies, such intradermal delivery devices, microarray patches, and sublingual formulations of vaccines, and others in development. The potential timeline to availability of these technologies varies and depends on their stage of development and the type of data necessary to achieve licensure. Some new delivery devices are anticipated to be introduced in 2017, such as intradermal devices for delivery of inactivated poliovirus vaccine to stretch vaccine supplies due to a supply limitation. Other new technologies requiring vaccine reformulation, such as microarray patches and sublingual vaccines, may become available in the long term (2021 and beyond). Development of many new technologies requires partnership between vaccine and technology manufacturers and identification of the applicable regulatory pathway. Interaction with public-sector stakeholders early on (through engagement with forums such as the World Health Organization's Immunization Practices Advisory Committee Delivery Technologies Working Group) is important to ensure suitability for immunization program use. Key considerations for programmatic suitability of a new vaccine, packaging, and delivery device include cold chain volume, costs, and health impact.

Vaccine vial stopper performance for fractional dose delivery of vaccines.

Shortages of vaccines such as inactivated poliovirus and yellow fever vaccines have been addressed by administering reduced-or fractional-doses, as recommended by the World Health Organization Strategic Advisory Group of Experts on Immunization, to expand population coverage in countries at risk. We evaluated 3 kinds of vaccine vial stoppers to assess their performance after increased piercing from repeated withdrawal of doses needed when using fractional doses (0.1 mL) from presentations intended for full-dose (0.5 mL) delivery. Self-sealing capacity and fragmentation of the stopper were assessed via modified versions of international standard protocols. All stoppers maintained self-sealing capacity after 100 punctures. The damage to stoppers measured as the fragmentation rate was within the target of ≤ 10% of punctures resulting in a fragment after as many as 50 punctures. We concluded that stopper failure is not likely to be a concern if existing vaccine vials containing up to 10 regular doses are used up to 50 times for fractional dose delivery.

Vial usage, device dead space, vaccine wastage, and dose accuracy of intradermal delivery devices for inactivated poliovirus vaccine (IPV).

INTRODUCTION: Intradermal delivery of a fractional dose of inactivated poliovirus vaccine (IPV) offers potential benefits compared to intramuscular (IM) delivery, including possible cost reductions and easing of IPV supply shortages. Objectives of this study were to assess intradermal delivery devices for dead space, wastage generated by the filling process, dose accuracy, and total number of doses that can be delivered per vial. METHODS: Devices tested included syringes with staked (fixed) needles (autodisable syringes and syringes used with intradermal adapters), a luer-slip needle and syringe, a mini-needle syringe, a hollow microneedle device, and disposable-syringe jet injectors with their associated filling adapters. Each device was used to withdraw 0.1-mL fractional doses from single-dose IM glass vials which were then ejected into a beaker. Both vial and device were weighed before and after filling and again after expulsion of liquid to record change in volume at each stage of the process. Data were used to calculate the number of doses that could potentially be obtained from multidose vials. RESULTS: Results show wide variability in dead space, dose accuracy, overall wastage, and total number of doses that can be obtained per vial among intradermal delivery devices. Syringes with staked needles had relatively low dead space and low overall wastage, and could achieve a greater number of doses per vial compared to syringes with a detachable luer-slip needle. Of the disposable-syringe jet injectors tested, one was comparable to syringes with staked needles. DISCUSSION: If intradermal delivery of IPV is introduced, selection of an intradermal delivery device can have a substantial impact on vaccine wasted during administration, and thus on the required quantity of vaccine that needs to be purchased. An ideal intradermal delivery device should be not only safe, reliable, accurate, and acceptable to users and vaccine recipients, but should also have low dead space, high dose accuracy, and low overall wastage to maximize the potential number of doses that can be withdrawn and delivered.

A model for oxygen conservation associated with titration during pediatric oxygen therapy.

BACKGROUND: Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration. AIM: To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia. METHODS: Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration. RESULTS: Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3), respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute. CONCLUSIONS: Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

Challenges of vaccine presentation and delivery: How can we design vaccines to have optimal programmatic impact?

Immunization program delivery strategies that enable high vaccine coverage, particularly in inaccessible and remote areas, are critical to achieving optimal vaccine impact. In addition to demonstration of safety and efficacy, there are many factors that influence whether a newly licensed vaccine will be introduced into a country's national immunization program, particularly in resource-constrained environments. This paper describes three case studies of novel approaches that represent the potential for improved programmatic impact by increasing vaccine accessibility in different ways. However, the pathway to regulatory approval, policy recommendation, and program introduction in low- and middle-income countries is complex, requiring engagement with multiple, diverse stakeholders. Consideration of aspects that affect uptake in low- and middle-income countries, during the product development stage, will help better position new or second-generation vaccine products for successful implementation to achieve public health impact.

Transdermal delivery of gentamicin using dissolving microneedle arrays for potential treatment of neonatal sepsis.

Neonatal infections are a leading cause of childhood mortality in low-resource settings. World Health Organization guidelines for outpatient treatment of possible serious bacterial infection (PSBI) in neonates and young infants when referral for hospital treatment is not feasible include intramuscular gentamicin (GEN) and oral amoxicillin. GEN is supplied as an aqueous solution of gentamicin sulphate in vials or ampoules and requires health care workers to be trained in dose calculation or selection of an appropriate dose based on the patient's weight band and to have access to safe injection supplies and appropriate sharps disposal. A simplified formulation, packaging, and delivery method to treat PSBI in low-resource settings could decrease user error and expand access to lifesaving outpatient antibiotic treatment for infants with severe infection during the neonatal period. We developed dissolving polymeric microneedles (MN) arrays to deliver GEN transdermally. MN arrays were produced from aqueous blends containing 30% (w/w) of GEN and two polymers approved by the US Food and Drug Administration: sodium hyaluronate and poly(vinylpyrrolidone). The arrays (19×19 needles and 500µm height) were mechanically strong and were able to penetrate a skin simulant to a depth of 378µm. The MN arrays were tested in vitro using a Franz Cell setup delivering approximately 4.45mg of GEN over 6h. Finally, three different doses (low, medium, and high) of GEN delivered by MN arrays were tested in an animal model. Maximum plasma levels of GEN were dose-dependent and ranged between 2 and 5µg/mL. The time required to reach these levels post-MN array application ranged between 1 and 6h. This work demonstrated the potential of dissolving MN arrays to deliver GEN transdermally at therapeutic levels in vivo.

Reservoir Cannulas for Pediatric Oxygen Therapy: A Proof-of-Concept Study.

Hypoxemia is a complication of pneumonia-the leading infectious cause of death in children worldwide. Treatment generally requires oxygen-enriched air, but access in low-resource settings is expensive and unreliable. We explored use of reservoir cannulas (RCs), which yield oxygen savings in adults but have not been examined in children. Toddler, small child, and adolescent breathing profiles were simulated with artificial lung and airway models. An oxygen concentrator provided flow rates of 0 to 5 L/min via a standard nasal cannula (NC) or RC, and delivered oxygen fraction (FdO2) was measured. The oxygen savings ratio (SR) and absolute flow savings (AFS) were calculated, comparing NC and RC. We demonstrated proof-of-concept that pendant RCs could conserve oxygen during pediatric therapy. SR mean and standard deviation were 1.1 ± 0.2 to 1.4 ± 0.4, 1.1 ± 0.1 to 1.7 ± 0.3, and 1.3 ± 0.1 to 2.4 ± 0.3 for toddler, small child, and adolescent models, respectively. Maximum AFS observed were 0.3 ± 0.3, 0.2 ± 0.1, and 1.4 ± 0.3 L/min for the same models. RCs have the potential to reduce oxygen consumption during treatment of hypoxemia in children; however, further evaluation of products is needed, followed by clinical analysis in patients.