Thermostabilization of adenovirus-vectored vaccines, removing the need for continual cold-chain storage

Challenges around affordable and reliable supply of vaccines that need to be transported and maintained in the cold-chain to remain effective are a hindrance to realizing their full potential. We will describe preparation for GMP manufacture and Phase I clinical trial of a new technology for vaccine thermostabilisation. We will also describe application of the same technology to a novel veterinary vaccine which is entering advanced development. The sugar-matrix thermostabilisation (SMT) technology involves application of vaccine in a simple disaccharide-based buffer to a non-woven matrix, similar to a pad of filter paper. This is followed by drying at ambient temperature and pressure (i.e. without a freezing step, enhancing suitability for freeze-sensitive products). The materials and process are simple and cheap. We have previously shown that SMT allows for the storage of viral vectored vaccines such as modified vaccinia virus Ankara (MVA) and adenovirus vectors at up to 45oC for several months with minimal losses1,2. More recently we have shown the technique can improve stability of various other vaccine types, ranging from virus-like particles through to enveloped RNA viruses. In many cases, the level of thermostability achieved would allow for “last mile” vaccine distribution via the ‘extended controlled temperature chain’ (ECTC), or even allow prolonged storage at uncontrolled ambient temperature. This would decrease distribution-associated costs/ losses and increase vaccination feasibility in hard-to-reach areas. We have now received funding for GMP manufacture and Phase I clinical trial of an SMT-formulated adenovirus-vectored rabies vaccine, ChAdOx2 RabG. We will describe the production of custom wet-laid non-woven matrices with optimized SMT performance, using processes and materials suitable for use as an input to a GMP process. We will further describe the development of simple apparatus suitable for executing the process for pilot GMP batches, the optimization of the drying process and excipient composition, and the application of frequency modulation spectroscopy for non-destructive analysis of residual moisture content. Finally, we will describe the application of the technology to a formulation of ChAdOx1 RVF, an adenovirus-vectored vaccine against Rift Valley Fever Virus which is being developed for both human and veterinary use. In this case, SMT is applied to an ultra-low-cost drug substance designed for veterinary use (cell lysate which has been clarified and ultrafiltered but not chromatographically purified), emphasizing the suitability of the approach for low-cost and One Health applications. 1. Alcock, R., et al., Long-Term Thermostabilization of Live Poxviral and Adenoviral Vaccine Vectors at Supraphysiological Temperatures in Carbohydrate Glass. Science Translational Medicine, 2010. 2(19):19ra12. 2. Dulal, P., et al., Potency of a thermostabilised chimpanzee adenovirus Rift Valley Fever vaccine in cattle. Vaccine, 2016. 34(20): p. 2296-8

Single administration vaccines: delivery challenges, in vivo performance, and translational considerations

Introduction With a limited global supply of vaccines and an increasing vaccine hesitancy, improving vaccination coverage has become a priority. Current vaccination regimes require multiple doses to be administered in a defined schedule where missed doses may lead to incomplete vaccine coverage and failure of immunization programmes. As such, there is an ever-increasing demand to convert multi-dose injectable vaccines into single-dose formats, often called single administration vaccines (SAVs). Areas covered This review summarizes recent developments in the field of SAVs, with a focus on pulsatile or controlled-release formulations. It will identify the technical challenges, translational as well as commercial barriers to SAVs development. Furthermore, the progress of SAV formulations for hepatitis B and polio vaccines will be reviewed thoroughly as case studies, with a focus on the development challenges and the preclinical immunogenicity/reactogenicity data. Expert opinion Despite the efforts to develop SAVs, few attempts have advanced to Phase-I trials. Considering the SAV development journey and bottlenecks, including commercial barriers from the early stages, may overcome some of the hurdles around the technology. The renewed global focus on vaccines since the COVID-19 pandemic could facilitate development of a new generation of technologies for pandemic preparedness including strategies for SAVs

Adenovirus-prime and baculovirus-boost heterologous immunization achieves sterile protection against malaria sporozoite challenge in a murine model.

With the increasing prevalence of artemisinin-resistant malaria parasites, a highly efficacious and durable vaccine for malaria is urgently required. We have developed an experimental virus-vectored vaccine platform based on an envelope-modified baculovirus dual-expression system (emBDES). Here, we show a conceptually new vaccine platform based on an adenovirus-prime/emBDES-boost heterologous immunization regimen expressing the Plasmodium falciparum circumsporozoite protein (PfCSP). A human adenovirus 5-prime/emBDES-boost heterologous immunization regimen consistently achieved higher sterile protection against transgenic P. berghei sporozoites expressing PfCSP after a mosquito-bite challenge than reverse-ordered or homologous immunization. This high protective efficacy was also achieved with a chimpanzee adenovirus 63-prime/emBDES-boost heterologous immunization regimen against an intravenous sporozoite challenge. Thus, we show that the adenovirus-prime/emBDES-boost heterologous immunization regimen confers sterile protection against sporozoite challenge by two individual routes, providing a promising new malaria vaccine platform for future clinical use

Evaluation of the Delivery of a Live Attenuated Porcine Reproductive and Respiratory Syndrome Virus as a Unit Solid Dose Injectable Vaccine

Solid dose vaccine formulation and delivery systems offer potential advantages over traditional liquid vaccine formulations. In addition to enhanced thermostability, needle-free delivery of unit solid dose injectable (USDI) vaccines offers safe, rapid, and error-free administration, with applicability to both human and animal health. Solid dose formulation technologies can be adapted for delivery of different vaccine formats including live attenuated vaccines, which remain the 'gold standard' for many disease targets. Porcine reproductive and respiratory syndrome viruses (PRRSV) cause one of the most economically important diseases affecting the global pig industry. Despite several shortcomings, live attenuated vaccines are widely used to control PRRSV. We optimised a freeze-dried USDI formulation of live attenuated PRRSV-1, which fully retained infectious titre, and evaluated its immunogenicity in comparison to virus delivered in liquid suspension via intramuscular and subcutaneous needle inoculation. Pigs vaccinated with the USDI formulation displayed vaccine viraemia, and PRRSV-specific antibody and T cell responses comparable to animals immunised with the liquid vaccine. The USDI vaccine formulation was stable for at least 6 months when stored refrigerated. These data demonstrate the potential for a solid dose vaccine delivery system as an alternative to conventional needle-syringe delivery of live attenuated PRRSV vaccines.Peer reviewe

Investigation of sugar-membrane vaccine stabilisation for improved vaccine thermostability and delivery

Vaccines and other biomolecules need to be maintained at specified storage temperatures from manufacture through to their end user. To satisfy this requirement an enormous network of fridges and freezers called the "cold chain" throughout the world must exist. This network may account for up to 80&amp;percnt; of the total cost of vaccination and is susceptible to failure causing loss of vaccines. Stabilisation strategies for vaccines available in the literature have been limited to a few techniques for a few vaccines. To address this problem a novel, cost-efficient, and simple sugar-membrane technology has been developed. Sugar-membrane technology involves desiccation of biomolecules formulated in stabilising sugars in a fibrous matrix and has previously been demonstrated to thermostabilise live viral vectored vaccines exposed to extremes of temperature for prolonged periods of time. The thesis investigates the applicability of the technology in stabilising a wide range of vaccines. The data reported demonstrate the effectiveness of the technology in thermostabilising the vaccines irrespective of the intrinsic complexities and thermo-sensitivity of the initial product. In addition, the thesis also studies the applicability of the technology in thermostabilisation of vaccines of veterinary importance. An accelerated stability study of sugar-membrane thermostabilised veterinary vaccines also demonstrated that the data are superior to those reported previously for the corresponding vaccines. However, the nature of the current matrix is not suitable for translation to human medicine. This thesis therefore investigates a range of new potentially GMP-compatible fibrous matrices to identify alternative membranes for use clinically. The data indicate that an alternative hydrophobic membrane after physical or chemical surface modification could be considered as an alternative support matrix for the technology. Finally, to understand the reasons for outstanding thermostability delivered by the current membrane in more detail, the physical and chemical properties of the matrix were investigated. Results from this systematic study identified inherent properties of the matrix which could be linked to the superior thermostabilising property of the membrane. These findings will be used for further optimisation of the technology and development towards a more GMP compatible support matrix.</p

Investigation of sugar-membrane vaccine stabilisation for improved vaccine thermostability and delivery

Vaccines and other biomolecules need to be maintained at specified storage temperatures from manufacture through to their end user. To satisfy this requirement an enormous network of fridges and freezers called the "cold chain" throughout the world must exist. This network may account for up to 80&percnt; of the total cost of vaccination and is susceptible to failure causing loss of vaccines. Stabilisation strategies for vaccines available in the literature have been limited to a few techniques for a few vaccines. To address this problem a novel, cost-efficient, and simple sugar-membrane technology has been developed. Sugar-membrane technology involves desiccation of biomolecules formulated in stabilising sugars in a fibrous matrix and has previously been demonstrated to thermostabilise live viral vectored vaccines exposed to extremes of temperature for prolonged periods of time. The thesis investigates the applicability of the technology in stabilising a wide range of vaccines. The data reported demonstrate the effectiveness of the technology in thermostabilising the vaccines irrespective of the intrinsic complexities and thermo-sensitivity of the initial product. In addition, the thesis also studies the applicability of the technology in thermostabilisation of vaccines of veterinary importance. An accelerated stability study of sugar-membrane thermostabilised veterinary vaccines also demonstrated that the data are superior to those reported previously for the corresponding vaccines. However, the nature of the current matrix is not suitable for translation to human medicine. This thesis therefore investigates a range of new potentially GMP-compatible fibrous matrices to identify alternative membranes for use clinically. The data indicate that an alternative hydrophobic membrane after physical or chemical surface modification could be considered as an alternative support matrix for the technology. Finally, to understand the reasons for outstanding thermostability delivered by the current membrane in more detail, the physical and chemical properties of the matrix were investigated. Results from this systematic study identified inherent properties of the matrix which could be linked to the superior thermostabilising property of the membrane. These findings will be used for further optimisation of the technology and development towards a more GMP compatible support matrix.</p

Investigation of sugar-membrane vaccine stabilisation for improved vaccine thermostability and delivery

Vaccines and other biomolecules need to be maintained at specified storage temperatures from manufacture through to their end user. To satisfy this requirement an enormous network of fridges and freezers called the “cold chain” throughout the world must exist. This network may account for up to 80% of the total cost of vaccination and is susceptible to failure causing loss of vaccines. Stabilisation strategies for vaccines available in the literature have been limited to a few techniques for a few vaccines. To address this problem a novel, cost-efficient, and simple sugar-membrane technology has been developed. Sugar-membrane technology involves desiccation of biomolecules formulated in stabilising sugars in a fibrous matrix and has previously been demonstrated to thermostabilise live viral vectored vaccines exposed to extremes of temperature for prolonged periods of time. The thesis investigates the applicability of the technology in stabilising a wide range of vaccines. The data reported demonstrate the effectiveness of the technology in thermostabilising the vaccines irrespective of the intrinsic complexities and thermo-sensitivity of the initial product. In addition, the thesis also studies the applicability of the technology in thermostabilisation of vaccines of veterinary importance. An accelerated stability study of sugar-membrane thermostabilised veterinary vaccines also demonstrated that the data are superior to those reported previously for the corresponding vaccines. However, the nature of the current matrix is not suitable for translation to human medicine. This thesis therefore investigates a range of new potentially GMP-compatible fibrous matrices to identify alternative membranes for use clinically. The data indicate that an alternative hydrophobic membrane after physical or chemical surface modification could be considered as an alternative support matrix for the technology. Finally, to understand the reasons for outstanding thermostability delivered by the current membrane in more detail, the physical and chemical properties of the matrix were investigated. Results from this systematic study identified inherent properties of the matrix which could be linked to the superior thermostabilising property of the membrane. These findings will be used for further optimisation of the technology and development towards a more GMP compatible support matrix.</p

Analysis of Health Sector Budget of Nepal

Introduction: Primarily, health sector connects two segments - medicine and public health, where medicine deals with individual patients and public health with the population health. Budget enables both the disciplines to function effectively. The Interim Constitution of Nepal, 2007 has adapted the inspiration of federalism and declared the provision of basic health care services free of cost as a fundamental right, which needs strengthening under foreseen federalism. Methods: An observational retrospective cohort study, aiming at examining the health sector budget allocation and outcome, was done. Authors gathered health budget figures (2001 to 2013) and facts published from authentic sources. Googling was done for further information. The keywords for search used were: fiscal federalism, health care, public health, health budget, health financing, external development partner, bilateral and multilateral partners and healthcare accessibility. The search was limited to English and Nepali-language report, articles and news published. Results: Budget required to meet the population's need is still limited in Nepal. The health sector budget could not achieve even gainful results due to mismatch in policy and policy implementation despite of political commitment. Conclusions: Since Nepal is transforming towards federalism, an increased complexity under federated system is foreseeable, particularly in the face of changed political scenario and its players. It should have clear goals, financing policy and strict implementation plans for budget execution, task performance and achieving results as per planning. Additionally, collection of revenue, risk pooling and purchasing of services should be better integrated between central government and federated states to horn effectiveness and efficiency.  Keywords: health care; budget; financing; unitary system; federalism

Stability of Chimpanzee Adenovirus Vectored Vaccines (ChAdOx1 and ChAdOx2) in Liquid and Lyophilised Formulations

Adenovirus vectored vaccines have entered global use during the COVID-19 pandemic, and are in development for multiple other human and veterinary applications. An attraction of the technology is the suitability of the vaccines for storage at 2–8 °C for months. Widely used COVID-19 vaccine ChAdOx1 nCoV-19 (University of Oxford/AstraZeneca) is based on a species E simian adenovirus. Species E simian serotypes have been used in a wide range of other development programs, but the stability of such vectors has not been extensively described in the peer-reviewed literature. Here, we explore the stability of two candidate vaccines based on two species E serotypes: a Rift Valley fever vaccine based upon the ChAdOx1 vector (Y25 serotype) used in ChAdOx1 nCoV-19, and a rabies vaccine based upon a ChAdOx2 vector (AdC68 serotype). We describe each vector’s stability in liquid and lyophilised formulations using in vitro and in vivo potency measurements. Our data support the suitability of liquid formulations of these vectors for storage at 2–8 °C for up to 1 year, and potentially for nonrefrigerated storage for a brief period during last-leg distribution (perhaps 1–3 days at 20 °C—the precise definition of acceptable last-leg storage conditions would require further product-specific data). Depending upon the level of inprocess potency loss that is economically acceptable, and the level of instorage loss that is compatible with maintenance of acceptable end-of-storage potency, a previously reported lyophilised formulation may enable longer term storage at 20 °C or storage for a number of days at 30 °C