Tools and approaches to ensure quality of vaccines throughout the cold chain

Vaccine handling practices and conformity to cold chain temperature requirements in selected regions of Tanzania: a descriptive cross-sectional study

Background

Poor handling practices and infrastructures for vaccine management, especially in remote rural areas, pose a challenge to the accessibility of safe and efficacious vaccines. This study assessed vaccine handling practices and conformity to cold chain systems in Tanzania.

Methods

A cross-sectional study was conducted from March 2022 to October 2022 using temperature loggers, checklists and questionnaires adopted from the WHO Vaccine Management Assessment Tool. The study sites were 35 facilities in Dar es salaam, Kigoma and Mtwara regions in Tanzania. Data was analysed by R statistical software.

Results

A total of 89 vaccine handling personnel with 22 personnel of less than 30 years old were included in this study. Seventy vaccine-handling personnel out of a total of 89 had adequate knowledge and 63 participants had good vaccine-handling practices. Fifty-three participants had no prior training in vaccine handling. Most (80%) of the facilities visited complied with the WHO cold chain storage standard of 2°C to 8°C in one month of observation; however, 29 facilities did not have temperature alarms to alert in cases of temperature changes and 24 facilities had no voltage regulators.

Conclusion

In this study, most of the facilities studied were compliant with WHO vaccine storage temperature requirements over a 30-day period. However, significant gaps were identified, including inadequate infrastructure for emergency situations and a lack of prior training on vaccine handling among the majority of personnel.

Evolution of microneedle applicators for vaccination: the role of the latch applicator in optimizing dissolving microneedle-based immunization

INTRODUCTION

Dissolving microneedles (DMN) offer advantages in vaccine delivery, such as enhanced immunogenicity and simplified administration, by targeting immune-rich layers of the skin. However, these benefits require precise and consistent delivery, which poses practical challenges. To address this, specialized applicators are essential for ensuring the accurate deployment of DMNs, making this technology a viable alternative to traditional methods, particularly in low- and middle-income countries (LMICs), where healthcare infrastructure is limited.

AREAS COVERED

In this review, we examine the advancements in DMN-based vaccination and applicator design, focusing on their joint effort. These innovations have improved the precision and efficiency of DMN vaccine delivery. Complex and costly early-stage applicators have evolved into simpler and more cost-effective designs. We highlight these developments in this review, with the latch applicator as a key example of a feature that enhances vaccine delivery.

EXPERT OPINION

Although applicator development has advanced DMN-based vaccination toward practical use, challenges remain. Key areas for further optimization include user friendliness, cost, packaging volume, and wear time. Once optimized, DMN vaccination may become a highly effective and accessible tool for global immunization, supporting efforts to achieve worldwide vaccine equality.

Stability Preparedness: The Not-So-Cold Case for Innovations in Vaccine Stability Modelling and Product Release

The rapid development of equitably accessible vaccines is paramount in addressing emerging global health challenges. The safety and efficacy of vaccines hinge significantly on their ability to remain stable from manufacturing throughout the supply chain and up to administration. Furthermore, the release of vaccines requires sufficient understanding of the stability profile to allow for expiration dating. In the event of a public health crisis, the time to generate the necessary stability data and the need for rapid product release are in direct opposition. Developing manufacturing platforms with thermostable product formulations for rapid response is therefore key to meeting CEPI's 100 Days Mission goal. This Review aims to highlight the need for stability preparedness through developing thermostable vaccine platforms and exploring innovative stability monitoring strategies that leverage advanced technologies, predictive modelling, and adaptive methodologies. By doing so, we seek to enhance the efficiency and effectiveness of stability assessments, supporting rapid development, regulatory approval, and widespread, equal distribution of vaccines-especially in an outbreak scenario. Finally, enhanced thermostability will allow for simplification across the supply chain, which will reduce the financial burden of vaccination programmes and enhance equitable access.

Advancements and Challenges in Peptide-Based Cancer Vaccination: A Multidisciplinary Perspective

With the continuous advancements in tumor immunotherapy, researchers are actively exploring new treatment methods. Peptide therapeutic cancer vaccines have garnered significant attention for their potential in improving patient outcomes. Despite its potential, only a single peptide-based cancer vaccine has been approved by the U.S. Food and Drug Administration (FDA). A comprehensive understanding of the underlying mechanisms and current development status is crucial for advancing these vaccines. This review provides an in-depth analysis of the production principles and therapeutic mechanisms of peptide-based cancer vaccines, highlights the commonly used peptide-based cancer vaccines, and examines the synergistic effects of combining these vaccines with immunotherapy, targeted therapy, radiotherapy, and chemotherapy. While some studies have yielded suboptimal results, the potential of combination therapies remains substantial. Additionally, we addressed the management and adverse events associated with peptide-based cancer vaccines, noting their relatively higher safety profile compared to traditional radiotherapy and chemotherapy. Lastly, we also discussed the roles of adjuvants and targeted delivery systems in enhancing vaccine efficacy. In conclusion, this review comprehensively outlines the current landscape of peptide-based cancer vaccination and underscores its potential as a pivotal immunotherapy approach.

Decomposition Analysis of Socioeconomic Inequalities in Vaccination Dropout in Remote and Underserved Settings in Ethiopia

Despite increments in immunization coverage over the past decades, substantial inequality due to wealth status has persisted in Ethiopia. This study aimed to decompose the concentration index into the contributions of individual factors to socioeconomic inequalities of childhood vaccination dropout in remote and underserved settings in Ethiopia by using a decomposition approach. A wealth index was developed by reducing 41 variables related to women's household living standards into nine factors by using principal component analysis. The components were further totaled into a composite score and divided into five quintiles (poorest, poorer, middle, richer, and richest). Vaccination dropout was calculated as the proportion of children who did not get the pentavalent-3 vaccine among those who received the pentavalent-1 vaccine. The concentration index was used to estimate socioeconomic inequalities in childhood vaccination dropout, which was then decomposed to examine the factors contributing to socioeconomic inequalities in vaccination dropout. The overall concentration index was -0.179 (P <0.01), confirming the concentration of vaccination dropout among the lowest wealth strata. The decomposition analyses showed that wealth index significantly contributed to inequalities in vaccination dropout (49.7%). Place of residence also explained -16.2% of the inequality. Skilled birth attendance and availability of a health facility in the kebele (the lowest administrative government structure) also significantly contributed (33.6% and 12.6%, respectively) to inequalities in vaccination dropout. Wealth index, place of residence, skilled birth attendance, and availability of a health facility in the kebele largely contributed to the concentration of vaccination dropout among the lowest wealth strata. Policymakers should address vaccination inequality by designing more effective strategies.

MA, Tovar-Rosero YY, Oñate AA, O'Ryan M. Two centuries of vaccination: historical and conceptual approach and future perspectives

Over the past two centuries, vaccines have been critical for the prevention of infectious diseases and are considered milestones in the medical and public health history. The World Health Organization estimates that vaccination currently prevents approximately 3.5-5 million deaths annually, attributed to diseases such as diphtheria, tetanus, pertussis, influenza, and measles. Vaccination has been instrumental in eradicating important pathogens, including the smallpox virus and wild poliovirus types 2 and 3. This narrative review offers a detailed journey through the history and advancements in vaccinology, tailored for healthcare workers. It traces pivotal milestones, beginning with the variolation practices in the early 17th century, the development of the first smallpox vaccine, and the continuous evolution and innovation in vaccine development up to the present day. We also briefly review immunological principles underlying vaccination, as well as the main vaccine types, with a special mention of the recently introduced mRNA vaccine technology. Additionally, we discuss the broad benefits of vaccines, including their role in reducing morbidity and mortality, and in fostering socioeconomic development in communities. Finally, we address the issue of vaccine hesitancy and discuss effective strategies to promote vaccine acceptance. Research, collaboration, and the widespread acceptance and use of vaccines are imperative for the continued success of vaccination programs in controlling and ultimately eradicating infectious diseases.

Mineralization Reduces the Toxicity and Improves Stability and Protective Immune Response Induced by Toxoplasma gondii

Vaccination is an ideal strategy for the control and prevention of toxoplasmosis. However, the thermostability and effectiveness of vaccines limit their application. Here, calcium mineralization was used to fabricate Toxoplasma gondii tachyzoites as immunogenic core-shell particles with improved immune response and thermostability. In the current study, T. gondii RH particles coated with mineralized shells were fabricated by calcium mineralization. The mineralized shells could maintain the T. gondii tachyzoites structural integrity for at least 12 months and weaken the virulence. Immunization of mice with mineralized tachyzoites induced high levels of T. gondii-specific antibodies and cytokines. The immunized mice were protected with a 100% survival rate in acute and chronic infection, and brain cyst burdens were significantly reduced. This study reported for the first time the strategy of calcium mineralization on T. gondii and proved that mineralized tachyzoites could play an immune protective role, thus expanding the application of biomineralization in T. gondii vaccine delivery.

A cross-sectional assessment of the effects of select training modalities on vaccine cold chain management

Background

Vaccines offer arguably the most cost-effective public health intervention. Vaccine supply chain management which is a critical building block faces many Human resources challenges mainly due to the special attributes of vaccines.

Objective

This study attempted to measure the effect of training on vaccine cold chain handler knowledge and practices.

Methods

A cross-sectional research design, using predominantly quantitative data collection techniques, was used. Facilities that have offered vaccination services for more than a year and report through the HMIS system were eligible for selection. Observation checklists and structured questionnaires were used. SPSS was used to analyse data.

Results

Vaccine cold chain management among the study group had an average score of 65.33% range (31-85%). The average knowledge score among the study respondents was 62.42% with a range (45-95%). The knowledge of respondents generally increases with an additional increase in the number of training modalities.

Conclusions

The status of VCCM is at about 65.33% below the target of 80% set by the EVM. The trainings have an effect on both knowledge of handlers and their practice especially when deployed in a multi-pronged design and thus these trainings need to be aligned to achieve synergy.

ABBREVIATIONS

CCE, Cold Chain Equipment; DHIS2, District Health Information Systems 2; DHO, District Health Officer; DPT, Diphtheria, Pertussis, Tetanus; DVS, District Vaccine Stores; EPI, Expanded Program for Immunisation; EVM, Effective Vaccine Management; FEFO, First Expiry First Out; GAVI, Global Alliance for Vaccines and Immunisation; HMIS, Health Information Management Systems; IRC, International Rescue Committee; KII, Key Informant Interview; LIAT, logistics indicator assessment tool; PATH, Program for Appropriate Technology in Health; PHC, Primary Health Care; QPPU, Quantification and Planning and Procurement Unit; SOPs, Standard Operating Procedures; SPSS, Statistical Package for Social Sciences; UNEPI, Uganda National Expanded Program for Immunisation; UNICEF, United Nations Children's Fund; VPD, Vaccine Preventable Diseases; VVM, Vaccine Vial Monitors; WHO, World Health Organisation.

Characterization of a Recombinant Thermostable Newcastle Disease Virus (NDV) Expressing Glycoprotein gB of Infectious Laryngotracheitis Virus (ILTV) Protects Chickens against ILTV Challenge

Infectious laryngotracheitis (ILT) and Newcastle disease (ND) are two important avian diseases that have caused huge economic losses to the poultry industry worldwide. Newcastle disease virus (NDV) has been used as a vector in the development of vaccines and gene delivery. In the present study, we generated a thermostable recombinant NDV (rNDV) expressing the glycoprotein gB (gB) of infectious laryngotracheitis virus (ITLV) based on the full-length cDNA clone of the thermostable TS09-C strain. This thermostable rNDV, named rTS-gB, displayed similar thermostability, growth kinetics, and pathogenicity compared with the parental TS09-C virus. The immunization data showed that rTS-gB induced effective ILTV- and NDV-specific antibody responses and conferred immunization protection against ILTV challenge in chickens. The efficacy of rTS-gB in alleviating clinical signs was similar to that of the commercial attenuated ILTV K317 strain. Furthermore, rTS-gB could significantly reduce viral shedding in cloacal and tracheal samples. Our study suggested that the rNDV strain rTS-gB is a thermostable, safe, and highly efficient vaccine candidate against ILT and ND.

On-demand biomanufacturing through synthetic biology approach

Biopharmaceuticals including protein therapeutics, engineered protein-based vaccines and monoclonal antibodies, are currently the mainstay products of the biotechnology industry. However, the need for specialized equipment and refrigeration during production and distribution poses challenges for the delivery of these technologies to the field and low-resource area. With the development of synthetic biology, multiple studies rewire the cell-free system or living cells to impact the portable, on-site and on-demand manufacturing of biomolecules. Here, we review these efforts and suggest future directions.

Vaccine supply chain management: An intelligent system utilizing blockchain, IoT and machine learning

Vaccination offers health, economic, and social benefits. However, three major issues-vaccine quality, demand forecasting, and trust among stakeholders-persist in the vaccine supply chain (VSC), leading to inefficiencies. The COVID-19 pandemic has exacerbated weaknesses in the VSC, while presenting opportunities to apply digital technologies to manage it. For the first time, this study establishes an intelligent VSC management system that provides decision support for VSC management during the COVID-19 pandemic. The system combines blockchain, internet of things (IoT), and machine learning that effectively address the three issues in the VSC. The transparency of blockchain ensures trust among stakeholders. The real-time monitoring of vaccine status by the IoT ensures vaccine quality. Machine learning predicts vaccine demand and conducts sentiment analysis on vaccine reviews to help companies improve vaccine quality. The present study also reveals the implications for the management of supply chains, businesses, and government.

Tunable Self-Assembled Peptide Hydrogel Sensor for Pharma Cold Supply Chain

Defrost sensors are a crucial element for proper functioning of the pharmaceutical cold chain. In this paper, the self-assembled peptide-based hydrogels were used to construct a sensitive defrost sensor for the transportation and storage of medications and biomaterials. The turbidity of the peptide hydrogel was employed as a marker of the temperature regime. The gelation kinetics under different conditions was studied to detect various stages of hydrogel structural transitions aimed at tuning the system properties. The developed sensor can be stored at room temperature for a long period, irreversibly indicates whether the product has been thawed, and can be adjusted to a specific temperature range and detection time.

Leveraging Lessons Learned from Yellow Fever and Polio Immunization Campaigns during COVID-19 Pandemic, Ghana, 2021

Ghana is a yellow fever-endemic country and experienced a vaccine-derived polio outbreak in July 2019. A reactive polio vaccination campaign was conducted in September 2019 and preventive yellow fever campaign in November 2020. On March 12, 2020, Ghana confirmed its first COVID-19 cases. During February-August 2021, Ghana received 1,515,450 COVID-19 vaccines through the COVID-19 Vaccines Global Access initiative and other donor agencies. We describe how systems and infrastructure used for polio and yellow fever vaccine deployment and the lessons learned in those campaigns were used to deploy COVID-19 vaccines. During March-August 2021, a total of 1,424,008 vaccine doses were administered in Ghana. By using existing vaccination and health systems, officials in Ghana were able to deploy COVID-19 vaccines within a few months with <5% vaccine wastage and minimal additional resources despite the short shelf-life of vaccines received. These strategies were essential in saving lives in a resource-limited country.

Adherence to WHO vaccine storage codes and vaccine cold chain management practices at primary healthcare facilities in Dalocha District of Silt'e Zone, Ethiopia

Background

The main elements of effective vaccine cold chain management at the immunization service delivery point are well-trained vaccine cold chain handlers, vaccine storage equipment, and appropriate vaccine management procedures. Vaccine cold chain handlers must have enough expertise to provide the correct vaccine at the right time, maintain vaccine potency, and minimize vaccination failures. The study assessed knowledge of vaccine cold chain handlers on vaccine cold chain management, adherence to the WHO vaccine storage codes and vaccine cold chain management practice at primary health facilities in Dalocha district of Silt'e zone.

Method

Institutional-based cross-sectional study was done at twenty-eight primary health facilities. One hundred forty primary health workers were drawn from four health centers and twenty-four health posts operating in Dalocha woreda of Silt'e zone, SNNPR, Ethiopia. A self-administered questionnaires and on-spot observation checklists were adapted from the WHO and WHO-UNICEF-effective vaccine management assessment tools to collect data from cold chain unit of the primary healthcare facilities. Data were entered to EPI data version 3.1; exported and analyzed using SPSS version 22. Statistical analysis was carried out to determine the level of knowledge, adherence to WHO cold chain management guideline and vaccine handling practice. The relationship that the knowledge of primary healthcare workers, primary healthcare workers training status, primary healthcare facilities' adherence to WHO vaccine storage codes, and length of work experience of primary health care workers have with the vaccine management practice were also explored

Result

Above Half (54%) of the respondents have satisfactory knowledge of vaccine cold chain management. One hundred (71.4%) vaccine cold chain handlers did point correctly to the recommended range of temperature (2°C -8°C) for vaccine storage. Around two-thirds (63.6%) of them were aware of the twice-daily temperature recordings. Nearly half, (46.2%) of primary healthcare facilities have experienced poor adherence to the WHO storage practice codes. Around three-fifths of the observed primary healthcare facilities have registered undesirable vaccine management practices. The primary healthcare workers who received training on vaccine cold chain management (χ2 = 0.058, p=0.015), served at primary health care facilities for more five years (χ2 =18.545, p≤0.001), shown good adherence to WHO vaccine storage code (χ2 =18.545, p≤0.001), have sufficient knowledge on vaccine cold chain management (χ2=4.210, p≤0.031) were all significantly associated with desirable vaccine cold chain management practice.

Conclusion

There is a gap in vaccine cold chain handlers’ knowledge about vaccine cold chain management and less than desirable adherence to WHO vaccine storage codes at primary healthcare facilities in Dalocha district. The majority of the observed primary health facilities have registered poor vaccine management practices. Everyone who has a stake in the cold chain management of vaccines should do their share, individually and collectively, to guarantee that everyone reaps the benefits of an effective cold chain.

Adverse events following immunization associated with coronavirus disease 2019 (COVID-19) vaccines: A descriptive analysis from VigiAccess

This study assessed adverse events following immunizations (AEFIs) reported on COVID-19 vaccines in VigiAccess and determined the reporting trends across all continents of the world. The study was cross-sectional quantitative in design. VigiAccess was searched on 10 November 10 2021 for reported adverse events following the introduction of COVID-19 vaccines. After entering the search term, "COVID-19 vaccines" in VigiAccess, AEFIs associated with nine approved brands of COVID-19 vaccines had been documented in the database. Data were captured among age groups, sex, and continents of the world and analyzed using Statistical Package for Social Sciences (SPSS) version 25. Overall, 2,457,386 AEFIs had been reported in VigiAccess at the time of the search. No causal associations could be established between the vaccines and the AEFIs. The public accessing VigiAccess data should therefore be made aware of this in order to not falsely attribute AEFIs to COVID-19 vaccines when assessing the database.

Vaccine cold chain management and cold storage technology to address the challenges of vaccination programs

The outbreaks of infectious diseases that spread across countries have generally existed for centuries. An example is the occurrence of the COVID-19 pandemic in 2020, which led to the loss of lives and economic depreciation. One of the essential ways of handling the spread of viruses is the discovery and administration of vaccines. However, the major challenges of vaccination programs are associated with the vaccine cold chain management and cold storage facilities. This paper discusses how vaccine cold chain management and cold storage technology can address the challenges of vaccination programs. Specifically, it examines different systems for preserving vaccines in either liquid or frozen form to help ensure that they are not damaged during distribution from manufacturing facilities. Furthermore, A vaccine is likely to provide very low efficacy when it is not properly stored. According to preliminary studies, the inability to store vaccine properly is partly due to the incompetency of many stakeholders, especially in technical matters. The novelty of this study is to thoroughly explore cold storage technology for a faster and more comprehensive vaccine distribution hence it is expected to be one of the reference and inspiration for stakeholders.

How to accelerate the supply of vaccines to all populations worldwide? Part II: Initial industry lessons learned and detailed technical reflections leveraging the COVID-19 situation

Vaccine discovery and vaccination against preventable diseases are one of most important achievements of the human race. While medical, scientific & technological advancements have kept in pace and found their way into treatment options for a vast majority of diseases, vaccines as a prevention tool in the public health realm are found languishing in the gap between such innovations and their easy availability/accessibility to vulnerable populations. This paradox has been best highlighted during the unprecedented crisis of the COVID-19 pandemic. As part of a two series publication on the vaccine industry's view on how to accelerate the availability of vaccines worldwide, this paper offers a deep dive into detailed proposals to enable this objective. These first-of-its-kind technical proposals gleaned from challenges and learnings from the COVID-19 pandemic are applicable to vaccines that are already on the market for routine pathogens as well as for production of new(er) vaccines for emerging pathogens with a public health threat potential. The technical proposals offer feasible and sustainable solutions in pivotal areas such as process validation, comparability, stability, post-approval changes, release testing, packaging, genetically modified organisms and variants, which are linked to manufacturing and quality control of vaccines. Ultimately these proposals aim to ease high regulatory complexity and heterogeneity surrounding the manufacturing & distribution of vaccines, by advocating the use of (1) Science and Risk based approaches, (2) global regulatory harmonization, (3) use of reliance, work-sharing, and recognition processes and (4) digitalization. Capitalizing & collaborating on such new-world advancements into the science of vaccines will eventually benefit the world by turning vaccines into vaccination, ensuring the health of everyone.

Evaluation of precipitation time of the aluminum salts adsorbed potentially frozen vaccines used in the Polish National Immunization Schedule for their pre-qualification before the administration

Purpose

Vaccines adsorbed on aluminum adjuvants irreversibly lose potency after freezing and their safety is affected. To prevent the administration of such vaccines, the World Health Organization developed the Shake Test designed to determine whether adsorbed vaccines have been frozen or not. However, the Shake Test is difficult and time-consuming when routinely conducted at the place of vaccination. In this study, a modified shake test for prequalification of potentially frozen vaccines was elaborated.

Materials and Methods

Vaccines used in the Polish Immunization Schedule were investigated and the analysis includes an assessment of precipitation time and the influence of the container type, amount and type of aluminum compound, and a volume of vaccine dose on the precipitation time.

Results

Significant differences between the precipitation time of frozen and non-frozen vaccines routinely used in the Polish Immunization Schedule were observed. The precipitation time of all non-frozen vaccines was above 30 minutes. The longest precipitation time of frozen vaccines was 10 minutes.

Conclusion

The finding of the study can be used in practice by the personnel administering vaccines to patients. Step-by-step recommendations for the preparation of the test have been proposed in the article.

Vaccine Procurement: A Conceptual Framework Based on Literature Review

Ensuring timely access to affordable vaccines has been acknowledged as a global public health priority, as also recently testified by the debate sparked during the COVID-19 pandemic. Effective vaccine procurement strategies are essential to reach this goal. Nevertheless, this is still a neglected research topic. A narrative literature review on vaccine procurement was conducted, by retrieving articles from four academic databases (PubMed/MEDLINE, Scopus, Embase, WebOfScience), 'grey' literature reports, and institutional websites. The aim was to clarify key concepts and definitions relating to vaccine procurement, describe main vaccine procurement methods, and identify knowledge gaps and future perspectives. A theoretical conceptual framework was developed of the key factors involved in vaccine procurement, which include quality and safety of the product, forecasting and budgeting, procurement legislation, financial sustainability, and plurality of manufacture, contracting, investment in training, storage and service delivery, monitoring and evaluation. This information can be useful to support policymakers during planning, implementation, and evaluation of regional and national vaccine procurement strategies and policies.

Evaluation of dog vaccination schemes against rabies in Kinshasa, Democratic Republic of the Congo

The traditional rabies control strategy based on annual mass vaccination of dogs appears to be costly and cumbersome. Given the existence of different risk zones for rabies transmission, the present study aimed at proposing risk-based vaccination schemes by considering canine population dynamics as well as vaccine efficacy and duration of immunity (DOI). The capital of the Democratic Republic of the Congo (RDC), Kinshasa, was chosen as study site. The turnover rate of dogs was used to assess their population dynamics in two low-roaming (<25 % of dogs are roaming) and in two high-roaming zones (>75 % of dogs are roaming). The sero-conversion rate was assessed in response to primo-vaccination in three age groups: 24 puppies (≤3months), 37 juveniles (4-12 months) and 22 adult dogs. The DOI was evaluated serologically by revaccinating dogs previously vaccinated since 1-2 years (n = 31), 2-3 years (n = 12) or 3-7.5 years (n = 4). Rapid Fluorescent Focus Inhibition Test was used to quantify antibodies. These data were used to implement vaccination outcome models.The turnover rate was twice as high in high-roaming zones (36 %) as that in lowroaming zones (17 %). Irrespective of roaming level, 75 % of dogs were less than 3 years old. The vaccine was equally effective in puppies (96 %), juvenile (97 %) and adult dogs (100 %, p = 0.24). The vaccine was effective in 93 % (11/12) of puppies without pre-vaccinal protective titers (≥0.5 IU/mL). The anamnestic response was strong within 5-8 days upon the booster vaccination, in 96 % (45/47) of dogs reported vaccinated 1-7.5 years before. This suggests that the vaccine provided a long-term protection (≥3 years) which is likely to occur in 75 % of dogs in Kinshasa.Hypothesizing a vaccination stop, the vaccination outcome model allowed to estimate the time point after which vaccination coverage would drop below 40 % in function of dog population turnover rate. The systematic vaccination of puppies as well as annual vaccination of dogs aged between 3 and 15 months or annual vaccination of all unvaccinated dogs aged more than 3 months of age appeared as valuable alternative to systematic annual mass vaccination.In conclusion, this study developed a vaccination outcome model pointing out the impact of dog population dynamics and of effective duration of immunity. It appears as a promising tool for designing cost-effective rabies vaccination campaigns.

Full-length G glycoprotein directly extracted from rabies virus with detergent and then stabilized by amphipols in liquid and freeze-dried forms

Pathogen surface antigens are at the forefront of the viral strategy when invading host organisms. These antigens, including membrane proteins (MPs), are broadly targeted by the host immune response. Obtaining these MPs in a soluble and stable form constitutes a real challenge, regardless of the application purposes (e.g. quantification/characterization assays, diagnosis, and preventive and curative strategies). A rapid process to obtain a native-like antigen by solubilization of a full-length MP directly from a pathogen is reported herein. Rabies virus (RABV) was used as a model for this demonstration and its full-length G glycoprotein (RABV-G) was stabilized with amphipathic polymers, named amphipols (APols). The stability of RABV-G trapped in APol A8-35 (RABV-G/A8-35) was evaluated under different stress conditions (temperature, agitation, and light exposure). RABV-G/A8-35 in liquid form exhibited higher unfolding temperature (+6°C) than in detergent and was demonstrated to be antigenically stable over 1 month at 5°C and 25°C. Kinetic modeling of antigenicity data predicted antigenic stability of RABV-G/A8-35 in a solution of up to 1 year at 5°C. The RABV-G/A8-35 complex formulated in an optimized buffer composition and subsequently freeze-dried displayed long-term stability for 2-years at 5, 25, and 37°C. This study reports for the first time that a natural full-length MP extracted from a virus, complexed to APols and subsequently freeze-dried, displayed long-term antigenic stability, without requiring storage under refrigerated conditions.

Use of Stability Modeling to Support Accelerated Vaccine Development and Supply

Stability assessment of pharmaceuticals in specific storage and shipment conditions is a key requirement to ensure that safe and efficacious products are administered to patients. This is particularly relevant for vaccines, with numerous vaccines strictly requiring cold storage to remain stable. When stability evaluation is exclusively based on real-time data, it may represent a bottleneck for rapid and effective vaccine access. Stability modeling for vaccines represents a key resource to predict stability based on accelerated stability studies; nevertheless, this approach is not fully exploited for these kinds of products. This is likely because of the complexity and diversity of vaccines, as well as the limited availability of dedicated guidelines or illustrative case studies. This article reports a cross-company perspective on stability modeling for vaccines. Several examples, based on the direct experience of the contributors, demonstrate that modeling approaches can be highly valuable to predict vaccines’ shelf life and behavior during shipment or manipulation. It is demonstrated that modeling methodologies need to be tailored to the nature of the vaccine, the available prior knowledge, and the monitored attributes. Considering that the well-established strategies reported in ICH or WHO guidelines are not always broadly applicable to vaccines, this article represents an important source of information for vaccine researchers and manufacturers, setting the grounds for further discussion within the vaccine industry and with regulators.

A fuzzy multi-criteria framework to identify barriers and enablers of the next-generation vaccine supply chain

Purpose

Due to the introduction of new vaccines in the child immunization program and inefficient vaccine supply chain (VSC), the universal immunization program (UIP), India is struggling to provide a full schedule of vaccination to the targeted children. In this paper, the authors investigate the critical factors for improving the performance of the existing VSC system by implementing the next-generation vaccine supply chain (NGVSC) in India.

Design/methodology/approach

The authors design a fuzzy multi-criteria framework using a fuzzy analytical hierarchical process (FAHP) and fuzzy multi-objective optimization on the basis of ratio analysis (FMOORA) to identify and analyze the critical barriers and enablers for the implementation of NGVSC. Further, the authors carry out a numerical simulation to validate the model.

Findings

The outcome of the analysis contends that demand forecasting is the topmost supply chain barrier and sustainable financing is the most important/critical enabler to facilitate the implementation of the NGVSC. In addition, the simulation reveals that the results of the study are reliable.

Social implications

The findings of the study can be useful for the child immunization policymakers of India and other developing countries to design appropriate strategies for improving existing VSC performance by implementing the NGVSC.

Originality/value

To the best of the authors’ knowledge, the study is the first empirical study to propose the improvement of VSC performance by designing the NGVSC.

Cold Chain Maintenance and Vaccine Stock Management Practices at Public Health Centers Providing Child Immunization Services in Jimma Zone, Oromia Regional State, Ethiopia: Multi-Centered, Mixed Method Approach

Background

Cold chain maintenance is the spine of an immunization program.

Objective

To examine the status of cold chain maintenance and evaluate knowledge of cold chain handlers and practices of vaccine management at public health centers providing immunization services in Jimma zone.

Methods

An institutional-based cross-sectional study supplemented with a qualitative method was conducted in 41 randomly selected health centers providing immunization service in districts of Jimma zone from October 31 to November 30, 2019. Pre-tested self-administered questionnaires and observation checklists developed from an effective vaccine management assessment tool (EVMAT) were used to collect quantitative data. Key informants were selected using the purposive sampling technique and an in-depth interview was conducted. Quantifiable data were analyzed using SPSS version 20 and chi-square was used to test the presence of association (p-value <0.05). Qualitative data were analyzed by thematic analysis and triangulated with quantitative findings.

Results

All public health centers had at least functional ice-lined refrigerators while 28 (68.3%) public health centers had functional deep freezers. Of the cold chain handlers, 120 (82.9%) had fair knowledge. Vaccine storage was appropriate per the World Health Organization's vaccine storage code in ice-lined refrigerators in 11 (24.4%) public health centers. Cold chain handlers’ years of service, types of training, availability of funds for cold chain maintenance, and availability of cold chain equipment at public health centers showed the presence of significant association with vaccine cold chain management practice.

Conclusion

The majority of cold chain handlers showed inadequate knowledge while a significant number showed poor practice of preserving the vaccines’ cold chain. Cold chain maintenance was not adequate in public health centers, necessitating attentive efforts of providing proper management of vaccine cold chains at immunization delivery points.

Modelling the inhibitors of cold supply chain using fuzzy interpretive structural modeling and fuzzy MICMAC analysis

The Cold Supply Chain (CSC) is an integral part of the supply chain of perishable products. The aim of this research is to examine the inhibitors that have a major impact on the performance of CSC operations in the United Arab Emirates (UAE). This study provides a synthesis and suggests a hierarchical model among CSC inhibitors and their respective relevance. The hierarchical synthesis of twelve (12) primary CSC inhibitors is achieved through a comprehensive literature review and consultation with academics and CSC professionals. This study used semi-structured interviews, a fuzzy interpretive structural modeling (FISM) and a Fuzzy-MICMAC (FMICMAC) analysis to explore and establish the relationship between and among identified inhibitors. FISM is used to examine the interaction between inhibitors, while FMICMAC analysis is used to examine the nature of inhibitors on the basis of their dependence and driving power. The results of the FISM and FMICMAC analysis show the inter-relationships and relative dominance of identified inhibitors. The results show that some inhibitors are of high strategic importance due to their high driving power and low dependence. These inhibitors seek more management attention in order to improve their effectiveness. The result of a hierarchical model helps to understand the influence of a particular inhibitor on others. 'Higher capital and operating costs' occupy the highest level in the FISM model. The 'fragmented cold supply chains', 'lack of skilled labor', 'inadequate information system infrastructure' and 'lack of commitment by top level management' had strong driving power but weak dependence, which characterizes them as independent inhibitors. Management should be extra careful when dealing with these inhibitors as they influence the effects of other variables at the top of the FISM hierarchy in the overall management of the cold supply chain. The study also suggests a number of recommendations for addressing these inhibitors in cold supply chains operating in the UAE. With due attention and care for these inhibitors, the operation of the cold supply chains is likely to be even more successful.

Human immunology and immunotherapy: main achievements and challenges

The immune system is a fascinating world of cells, soluble factors, interacting cells, and tissues, all of which are interconnected. The highly complex nature of the immune system makes it difficult to view it as a whole, but researchers are now trying to put all the pieces of the puzzle together to obtain a more complete picture. The development of new specialized equipment and immunological techniques, genetic approaches, animal models, and a long list of monoclonal antibodies, among many other factors, are improving our knowledge of this sophisticated system. The different types of cell subsets, soluble factors, membrane molecules, and cell functionalities are some aspects that we are starting to understand, together with their roles in health, aging, and illness. This knowledge is filling many of the gaps, and in some cases, it has led to changes in our previous assumptions; e.g., adaptive immune cells were previously thought to be unique memory cells until trained innate immunity was observed, and several innate immune cells with features similar to those of cytokine-secreting T cells have been discovered. Moreover, we have improved our knowledge not only regarding immune-mediated illnesses and how the immune system works and interacts with other systems and components (such as the microbiome) but also in terms of ways to manipulate this system through immunotherapy. The development of different types of immunotherapies, including vaccines (prophylactic and therapeutic), and the use of pathogens, monoclonal antibodies, recombinant proteins, cytokines, and cellular immunotherapies, are changing the way in which we approach many diseases, especially cancer.

Redesigning immunization supply chains: Results from three country analyses

INTRODUCTION

Immunization supply chains (iSC) are essential for ensuring access to vaccines that prevent diseases. Guinea, Madagascar, and Niger initiated iSC system design efforts to conduct analysis of alternative supply chain scenarios to identify areas for improvement.

METHODOLOGY

Key stakeholders from Ministries of Health and immunization programs identified bottlenecks in the current iSC and prioritized five general design scenarios to model in each country. Scenarios included aspects of integration, changing supply chain levels and delivery frequency, ignoring administrative boundaries, and direct delivery. Primary and secondary data were collected and cleaned. Analysis was completed using Supply Chain Guru (Madagascar and Niger) and AnyLogistix (Guinea) modeling software to build a virtual representation of the iSC physical components and operating policies.

RESULTS

Modeling results were compared using both quantitative and qualitative criteria (total operating costs, cost per dose, cold chain capacity, risk of mishandling, logistics burden on healthcare workers, feasibility to implement, and equity). Using a Stop Light Analysis for user-friendly understanding of positive, negative or minimal impact on scenarios, cost savings were realized in most scenarios in Madagascar (except using autonomous aerial vehicles); proposed scenarios in Guinea increased costs or had minimal impact; in Niger, eliminating regional tiers reduced costs. Facility level cold chain was sufficient in all countries. Effect on qualitative indicators largely depended on the scenario and country context.

DISCUSSION

Similarities in scenarios selected were seen across the three countries. Results suggest that efficiencies can be found through changes to the iSC design, but the benefits of each scenario must be considered in the country context. Results of the analysis do not provide "the right answer" but rather options and guidance which then must be grounded in the country context and used as evidence for decision making to ensure reliable availability of vaccines.

[Evaluation on monitoring effect of the electronic vaccine vial monitor label]

The cold chain safety of vaccines is a global issue. The electronic vaccine vial monitor (eVVM) label can monitor the temperature of vaccines in real time and provide "early warning" prompts. In order to comprehensively evaluate the monitoring efficiency of eVVM, this study selected 75 eVVM labels and distributed them with a total of 600 vaccine vial monitor (VVM) labels of four different types in different experimental environment (2-8℃, -20℃ and 40℃), and used a temperature recorder as "gold standard". The results showed that the accuracy of the eVVM labels and VVM labels in high temperature environment was as same as that of the temperature recorder ( P = 0.195). The accuracy of low temperature anomalies report and high temperature anomalies report of eVVM labels was 100%, which was better than those reported by VVM labels. Therefore, eVVM labels have high monitoring accuracy, which is suitable not only for ordinary environments, but also for severe temperature environments. It should be helpful for the improvement of the efficiency and accuracy of cold chain monitoring.

Development of vaccine formulations: past, present, and future

The current situation, heavily influenced by the ongoing pandemic, puts vaccines back into the spotlight. However, the conventional and traditional vaccines present disadvantages, particularly related to immunogenicity, stability, and storage of the final product. Often, such products require the maintenance of a “cold chain,” impacting the costs, the availability, and the distribution of vaccines. Here, after a recall of the mode of action of vaccines and the types of vaccines currently available, we analyze the past, present, and future of vaccine formulation. The past focuses on conventional formulations, the present discusses the use of nanoparticles for vaccine delivery and as adjuvants, while the future presents microneedle patches as alternative formulation and administration route. Finally, we compare the advantages and disadvantages of injectable solutions, nanovaccines, and microneedles in terms of efficacy, stability, and patient-friendly design.

Different approaches to vaccine formulation development, the conventional vaccine formulations from the past, the current development of lipid nanoparticles as vaccines, and the near future microneedles formulations are discussed in this review. 

Association between season of vaccination and antibody levels against infectious diseases

Vaccination has reduced the disease burden of vaccine-preventable diseases. However, the extent to which seasonal cycles of immunity could influence vaccine-induced immunity is not well understood. A national cross-sectional serosurveillance study performed in the Netherlands (Pienter-2) yielded data to investigate whether season of vaccination was associated with antibody responses induced by DT-IPV (diphtheria, tetanus and poliomyelitis), MMR (measles, mumps and rubella) and meningococcus C (MenC) vaccines in children. In total, 434 children met the inclusion criteria to study DT-IPV immunity, 811 for MMR and 311 for MenC. Differences in log(antibody levels) by season of vaccination were investigated with linear multivariable regression analyses. Seroconversion rates varied according to season of vaccination for rubella (90% of autumn-vaccinated children vs. 99% of winter-vaccinated had concentrations above cut-off levels). Summer-vaccinated boys showed a slower decline of tetanus antibodies (6% per month), in comparison with winter-vaccinated boys. In conclusion, season of vaccination showed little association with immunological protection. However, a number of associations were seen with a P-value of about 0.03; and adding data from a just-completed nationwide serological study might add more power to the current study. Further immunological and longitudinal investigations could help understand the mechanisms of seasonal influence in vaccine-induced responses.

Decomposition of socioeconomic inequalities in child vaccination in Ethiopia: results from the 2011 and 2016 demographic and health surveys

OBJECTIVES

Monitoring and addressing unnecessary and avoidable differences in child vaccination is a critical global concern. This study aimed to assess socioeconomic inequalities in basic vaccination coverage among children aged 12-23 months in Ethiopia.

DESIGN, SETTING AND PARTICIPANTS

Secondary analyses of cross-sectional data from the two most recent (2011 and 2016) Ethiopia Demographic and Health Surveys were performed. This analysis included 1930 mother-child pairs in 2011 and 2004 mother-child pairs in 2016.

OUTCOME MEASURES

Completion of basic vaccinations was defined based on whether a child received a single dose of Bacille Calmette-Guerin (BCG), three doses of diphtheria, tetanus toxoids and pertussis (DTP), three doses of oral polio vaccine and one dose of measles vaccine.

METHODS

The concentration Curve and Concentration Indices (CCIs) were used to estimate wealth related to inequalities. The concentration indices were also decomposed to examine the contributing factors to socioeconomic inequalities in childhood vaccination.

RESULTS

From 2011 to 2016, the proportion of children who received basic vaccination increased from 24.6% (95% CI 21.4% to 28.0%) to 38.6% (95% CI 34.6% to 42.9%). While coverage of BCG, DTP and polio immunisation increased during the study period, the uptake of measles vaccine decreased. The positive concentration index shows that basic vaccination coverage was pro-rich (CCI=0.212 in 2011 and CCI=0.172 in 2016). The decomposition analysis shows that use of maternal health services such as family planning and antenatal care, socioeconomic status, exposure to media, urban-rural residence and maternal education explain inequalities in basic vaccination coverage in Ethiopia.

CONCLUSIONS

Childhood vaccination coverage was low in Ethiopia. Vaccination was less likely in poorer than in richer households. Addressing wealth inequalities, enhancing education and improving maternal health service coverage will reduce socioeconomic inequalities in basic vaccination uptake in Ethiopia.

Stability Studies of the Vaccine Adjuvant U-Omp19

Unlipidated outer membrane protein 19 (U-Omp19) is a novel mucosal adjuvant in preclinical development to be used in vaccine formulations. U-Omp19 holds two main properties, it is capable of inhibiting gastrointestinal and lysosomal peptidases, increasing the amount of co-administered antigen that reaches the immune inductive sites and its half-life inside cells, and it is able to stimulate antigen presenting cells in vivo. These activities enable U-Omp19 to enhance the adaptive immune response to co-administrated antigens.

To characterize the stability of U-Omp19 we have performed an extensive analysis of its physicochemical and biological properties in a 3-year long-term stability study, and under potentially damaging freeze-thawing and lyophilization stress processes. Results revealed that U-Omp19 retains its full protease inhibitor activity, its monomeric state and its secondary structure even when stored in solution for 36 months or after multiple freeze-thawing cycles. Non-enzymatic hydrolysis resulted the major degradation pathway for storage in solution at 4 °C or room temperature which can be abrogated by lyophilization yet increasing protein tendency to form aggregates.

This information will play a key role in the development of a stable formulation of U-Omp19, allowing an extended shelf-life during manufacturing, storage, and shipping of a future vaccine containing this pioneering adjuvant.

A vaccine cold chain temperature monitoring study in the United Mexican States

Vacine cold chain assessments conducted in various parts of the world indicate that maintaining equipment at the temperature range recommended by the World Health Organization (WHO) is not always observed. It has been also the case that staff rather prioritize protecting vaccine from heat damage, thus often exposing vaccines to freezing temperatures. As a result, inadvertent freezing of vaccines is a largely overlooked problem all over the world. In a recent systematic review, comparison of the occurrence of freezing temperatures during storage and transport were found to be a global problem occurring both in the resource-rich as well as the resource-limited settings. A vaccine cold chain temperature monitoring study was conducted using standard WHO study protocol with the objective to document potential problems and to identify appropriate control measures. Multiple temperature monitoring devices were used in the study to evaluate user friendliness of these devices and staff attitudes towards them. In general, majority of the time, temperatures were kept between recommended temperature range of 2-8 °C. Temperature variation got wider when products moved from 3PL Laboratory to service points. The wider variation is found at the service points. High temperature excursions were observed or short periods of time while exposures to freezing temperatures were more both higher in number and duration, however, shake test with these vaccines indicated no freeze damage. 91% of staff believed that they did not have the necessary tools to detect if a vaccine had been damaged by a temperature excursion outside the 2-8 °C range, and all staff believed that inclusion of such devices (e.g. vaccine vial monitor) in the system would improve cold chain operations as they have became aware of problematic areas through this study.

[Assessment of vaccination status and booster vaccinations in adolescents attending school in Libreville, Gabon]

Introduction

La vaccination chez l'adolescent est particulière et le statut vaccinal de ce dernier est peu connu. L'objectif de cette étude était d'apprécier ce statut vaccinal et d'identifier les facteurs associés à la compliance vaccinale chez les adolescents scolarisés à Libreville.

Méthodes

Une enquête observationnelle transversale descriptive a été réalisée chez les élèves des classes de 6^edu Lycée national Léon MBA de Libreville.

Résultats

Au total, 304 élèves ont été inclus dans l'étude. L'âge moyen des élèves était de 11,60±1,20 ans et le sexe ratio était de 0,6. Deux cent soixante-six enfants (87,5%) vivaient avec leur géniteur direct (père et/ou mère). Le nombre moyen d'enfants par famille était de 4. Le taux de couverture vaccinale était de 78,3%. Le nombre d'enfants par famille n'était pas associée à la couverture vaccinale des vaccins du PEV (p=0,088), par contre les enfants vivant avec au moins l'un des parents avaient une meilleure couverture vaccinale respectivement par les vaccins du PEV (p=0,025) et les vaccins hors PEV (p=0,035). Les facteurs évoqués par les parents pour expliquer la non-vaccination étaient le manque d'information (30,59%), l'oubli (24,67%) et le manque de moyens financiers (12,82%).

Conclusion

La couverture vaccinale des adolescents scolarisés à Libreville semble relativement proche des objectifs du PEV, mais elle reste associée à la situation familiale. D'autres campagnes de sensibilisation seraient utiles pour améliorer cette couverture vaccinale au Gabon.

Salt Enhances the Thermostability of Enteroviruses by Stabilizing Capsid Protein Interfaces

Enteroviruses are common agents of infectious disease that are spread by the fecal-oral route. They are readily inactivated by mild heat, which causes the viral capsid to disintegrate or undergo conformational change. While beneficial for the thermal treatment of food or water, this heat sensitivity poses challenges for the stability of enterovirus vaccines. The thermostability of an enterovirus can be modulated by the composition of the suspending matrix, though the effects of the matrix on virus stability are not understood. Here, we determined the thermostability of four enterovirus strains in solutions with various concentrations of NaCl and different pH values. The experimental findings were combined with molecular modeling of the protein interaction forces at the pentamer and the protomer interfaces of the viral capsids. While pH only had a modest effect on thermostability, increasing NaCl concentrations raised the breakpoint temperatures of all viruses tested by up to 20°C. This breakpoint shift could be explained by an enhancement of the van der Waals attraction forces at the two protein interfaces. In comparison, the (net repulsive) electrostatic interactions were less affected by NaCl. Depending on the interface considered, the breakpoint temperature shifted by 7.5 or 5.6°C per 100-kcal/(mol·Å) increase in protein interaction force.IMPORTANCE The genus Enterovirus encompasses important contaminants of water and food (e.g., coxsackieviruses), as well as viruses of acute public health concern (e.g., poliovirus). Depending on the properties of the surrounding matrix, enteroviruses exhibit different sensitivities to heat, which in turn influences their persistence in the environment, during food treatment, and during vaccine storage. Here, we determined the effect of NaCl and pH on the heat stability of different enteroviruses and related the observed effects to changes in protein interaction forces in the viral capsid. We demonstrate that NaCl renders enteroviruses thermotolerant and that this effect stems from an increase in van der Waals forces at different protein subunits in the viral capsid. This work sheds light on the mechanism by which salt enhances virus stability.

Current status and future directions of fish vaccines employing virus-like particles

In most breeding schemes, fish are cultured in enclosed spaces, which greatly increases the risk of outbreaks where the onset of infectious diseases can cause massive mortality and enormous economic losses. Vaccination is the most effective and long-term measure for improving the basic make-up of a fish farm. As the relationship between antibody and antigen is similar to that between screw and nut, similarity in the shape or nature of the vaccine antigen to the original pathogen is important for achieving a satisfactory/good/excellent antibody response with a vaccine. Virus-like particles (VLPs) best fulfil this requirement as their tertiary structure mimics that of the native virus. For this reason, VLPs have been attracting attention as next-generation vaccines for humans and animals, and the effects of various types of VLP vaccines on humans and livestock have been examined. Recent studies of VLP-based fish vaccines indicate that these vaccines are promising, and raise hopes of extending their use in the near future. In this review, the structural properties and immunogenicity of VLP-based vaccines against fish viruses such as infectious pancreatic necrosis virus (IPNV), salmonid alphavirus (SAV), nervous necrosis virus (NNV) and iridovirus are introduced/summarized. The NNV VLP vaccine is the most-studied VLP-based vaccine against fish viruses. Therefore, the current status of NNV VLP research is highlighted in this review, which deals with the advantages of using VLPs as vaccines, and the expression systems for producing them. Moreover, the need for lyophilized VLPs and oral VLP delivery is discussed. Finally, future directions for the development of VLP vaccines in the fish vaccine field are considered.

Key steps in vaccine development

OBJECTIVE

The goal of a vaccine is to prime the immune response so the immune memory can facilitate a rapid response to adequately control the pathogen on natural infection and prevent disease manifestation. This article reviews the main elements that provide for the development of safe and effective vaccines.

DATA SOURCES

Literature covering target pathogen epidemiology, the key aspects of the functioning immune response underwriting target antigen selection, optimal vaccine formulation, preclinical and clinical trial studies necessary to deliver safe and efficacious immunization.

STUDY SELECTIONS

Whole live, inactivated, attenuated, or partial fractionated organism-based vaccines are discussed in respect of the balance of reactogenicity and immunogenicity. The use of adjuvants to compensate for reduced immunogenicity is described. The requirements from preclinical studies, including establishing a proof of principle in animal models, the design of clinical trials with healthy volunteers that lead to licensure and beyond are reviewed.

RESULTS

The 3 vaccine development phases, preclinical, clinical, and post-licensure, integrate the requirements to ensure safety, immunogenicity, and efficacy in the final licensed product. Continuing monitoring of efficacy and safety in the immunized populations is essential to sustain confidence in vaccination programs.

CONCLUSION

In an era of increasing vaccine hesitancy, the need for a better and widespread understanding of how immunization acts to counteract the continuing and changing risks from the pathogenic world is required. This demands a societal responsibility for obligate education on the benefits of vaccination, which as a medical intervention has saved more lives than any other procedure.

A systematic literature review of healthcare supply chain and implications of future research

Purpose

This paper aims to review the healthcare supply chain (HSC) literature along various areas and to find out the gap in it.

Design/methodology/approach

In total, 143 research papers were reviewed during 1996-2017. A critical review was carried out in various dimensions such as research methodologies/data collection method (empirical, case study and literature review) and inquiry mode of research methodology (qualitative, quantitative and mixed), country-specific, targeted area, research aim and year of publication.

Findings

Supply chain (SC) operations, performance measurement, inventory management, lean and agile operation, and use of information technology were well studied and analyzed, however, employee and customer training, tracking and visibility of medicines, cold chain management, human resource practices, risk management and waste management are felt to be important areas but not much attention were made in this direction.

Research limitations/implications

Mainly drug and vaccine SC were considered in current study of HSC while SC along healthcare equipment and machine, hospitality and drug manufacturing related papers were excluded in this study.

Practical implications

This literature review has recognized and analyzed various issues relevant to HSC and shows the direction for future research to develop an efficient and effective HSC.

Originality/value

The insight of various aspects of HSC was explored in general for better and deeper understanding of it for designing of an efficient and competent HSC. The outcomes of the study may form a basis to decide direction of future research.

Yellow Fever: Integrating Current Knowledge with Technological Innovations to Identify Strategies for Controlling a Re-Emerging Virus

Yellow fever virus (YFV) represents a re-emerging zoonotic pathogen, transmitted by mosquito vectors to humans from primate reservoirs. Sporadic outbreaks of YFV occur in endemic tropical regions, causing a viral hemorrhagic fever (VHF) associated with high mortality rates. Despite a highly effective vaccine, no antiviral treatments currently exist. Therefore, YFV represents a neglected tropical disease and is chronically understudied, with many aspects of YFV biology incompletely defined including host range, host–virus interactions and correlates of host immunity and pathogenicity. In this article, we review the current state of YFV research, focusing on the viral lifecycle, host responses to infection, species tropism and the success and associated limitations of the YFV-17D vaccine. In addition, we highlight the current lack of available treatments and use publicly available sequence and structural data to assess global patterns of YFV sequence diversity and identify potential drug targets. Finally, we discuss how technological advances, including real-time epidemiological monitoring of outbreaks using next-generation sequencing and CRISPR/Cas9 modification of vector species, could be utilized in future battles against this re-emerging pathogen which continues to cause devastating disease.

Stabilization and formulation of a recombinant Human Cytomegalovirus vector for use as a candidate HIV-1 vaccine

Live attenuated viral vaccine/vector candidates are inherently unstable and infectivity titer losses can readily occur without defining appropriate formulations, storage conditions and clinical handling practices. During initial process development of a candidate vaccine against HIV-1 using a recombinant Human Cytomegalovirus vector (rHCMV-1), large vector titer losses were observed after storage at 4 °C and after undergoing freeze-thaw. Thus, the goal of this work was to develop candidate frozen liquid formulations of rHCMV-1 with improved freeze-thaw and short-term liquid stability for potential use in early clinical trials. To this end, a virus stability screening protocol was developed including use of a rapid, in vitro cell-based immunofluorescence focus assay to quantitate viral titers. A library of ∼50 pharmaceutical excipients (from various known classes of additives) were evaluated for their effect on vector stability after freeze-thaw cycling or incubation at 4 °C for several days. Certain additives including sugars and polymers (e.g., trehalose, sucrose, sorbitol, hydrolyzed gelatin, dextran 40) as well as removal of NaCl (lower ionic strength) protected rHCMV-1 against freeze-thaw mediated losses in viral titers. Optimized solution conditions (e.g., solution pH, buffers and sugar type) slowed the rate of rHCMV-1 titer losses in the liquid state at 4 °C. After evaluating various excipient combinations, three new candidate formulations were designed and rHCMV-1 stability was benchmarked against both the currently-used and a previously reported formulation. The new candidate formulations were significantly more stable in terms of reducing rHCMV-1 titer losses after 5 freeze-thaw cycles or incubation at 4 °C for 30 days. This case study highlights the utility of semi-empirical design of frozen liquid formulations of a live viral vaccine candidate, where protection against infectivity titer losses due to freeze-thaw and short-term liquid storage are sufficient to enable more rapid initiation of early clinical trials.

Simultaneous in situ visualization and quantitation of dual antigens adsorbed on adjuvants using high content analysis

Aim: Traditional antigenicity assay requires antigen recovery from the particulate adjuvants prior to analysis. An in situ method was developed for interrogating vaccine antigens with monoclonal antibodies while being adsorbed on adjuvants. Materials & methods: The fluorescence imaging-based high content analysis was used to visualize the antigen distribution on adjuvant agglomerates and to analyze the antigenicity for adsorbed antigens. Results: Simultaneous visualization and quantitation were achieved for dual antigens in a bivalent human papillomavirus vaccine with uniquely labeled antibodies. Good agreement was observed between the in situ multiplexed assays with well-established sandwich enzyme-linked immunosorbent assays. Conclusion: The streamlined procedures and the amenability for multiplexing make the in situ antigenicity analysis a favorable choice for in vitro functional assessment of bionanoparticles as vaccine antigens.

Prioritizing the vaccine supply chain issues of developing countries using an integrated ISM-fuzzy ANP framework

Purpose

Delivering vaccines to the children who need them requires a supply chain that is efficient and effective. In most of the developing countries, however, the unknown and unresolved supply chain issues are causing inefficiencies in distributing vaccines. There is, therefore, a great need in such countries to recognize the issues that cause delays in vaccine delivery. With this purpose, the present study aims to identify and analyze the key issues in the supply chain of basic vaccines required to immunize children in developing countries.

Design/methodology/approach

Based on a field survey of three states of India, in-depth review of relevant literature and experts’ opinions, 25 key issues were recognized as factors of the vaccine supply chain (VSC) and categorized into five main domains. Using integrated interpretive structural modeling and fuzzy analytic network process approaches, the issues have been prioritized to determine their relative importance in the VSC. In addition, a sensitivity analysis has been performed to investigate the priority stability of the issues.

Findings

The results of the analysis show that among the five domains of VSC issues, the economic domain with a weight of 0.4262 is the most important domain, followed by the management (0.2672), operational (0.2222), environmental (0.0532) and social (0.0312).

Research limitations/implications

This study focuses on the prioritization of VSC issues; therefore, the results of the present study can provide direction to the decision-makers of immunization programs of developing countries in driving their efforts and resources on eliminating the most important obstacles to design successful vaccination programs.

Originality/value

To the authors’ knowledge, this paper is first to provide a direction to the decision-makers in identifying and managing important issues through the use of an analytical approach.

Characterizing and Minimizing Aggregation and Particle Formation of Three Recombinant Fusion-Protein Bulk Antigens for Use in a Candidate Trivalent Rotavirus Vaccine

In a companion paper, the structural integrity, conformational stability, and degradation mechanisms of 3 recombinant fusion-protein antigens comprising a non-replicating rotavirus (NRRV) vaccine candidate (currently being evaluated in early-stage clinical trials) are described. In this work, we focus on the aggregation propensity of the 3 NRRV antigens coupled to formulation development studies to identify common frozen bulk candidate formulations. The P2-VP8-P[8] antigen was most susceptible to shaking and freeze-thaw-induced aggregation and particle formation. Each NRRV antigen formed aggregates with structurally altered protein (with exposed apolar regions and intermolecular β-sheet) and dimers containing a non-native disulfide bond. From excipient screening studies with P2-VP8-P[8], sugars or polyols (e.g., sucrose, trehalose, mannitol, sorbitol) and various detergents (e.g., Pluronic F-68, polysorbate 20 and 80, PEG-3350) were identified as stabilizers against aggregation. By combining promising additives, candidate bulk formulations were optimized to not only minimize agitation-induced aggregation, but also particle formation due to freeze-thaw stress of P2-VP8-P[8] antigen. Owing to limited material availability, stabilization of the P2-VP8-P[4] and P2-VP8-P[6] was confirmed with the lead candidate P2-VP8-P[8] formulations. The optimization of these bulk NRRV candidate formulations is discussed in the context of subsequent drug product formulations in the presence of aluminum adjuvants.