Vaccine manufacturing

Formulation development and comparability studies with an aluminum-salt adjuvanted SARS-CoV-2 spike ferritin nanoparticle vaccine antigen produced from two different cell lines

The development of safe and effective second-generation COVID-19 vaccines to improve affordability and storage stability requirements remains a high priority to expand global coverage. In this report, we describe formulation development and comparability studies with a self-assembled SARS-CoV-2 spike ferritin nanoparticle vaccine antigen (called DCFHP), when produced in two different cell lines and formulated with an aluminum-salt adjuvant (Alhydrogel, AH). Varying levels of phosphate buffer altered the extent and strength of antigen-adjuvant interactions, and these formulations were evaluated for their (1) in vivo performance in mice and (2) in vitro stability profiles. Unadjuvanted DCFHP produced minimal immune responses while AH-adjuvanted formulations elicited greatly enhanced pseudovirus neutralization titers independent of ∼100%, ∼40% or ∼10% of the DCFHP antigen adsorbed to AH. These formulations differed, however, in their in vitro stability properties as determined by biophysical studies and a competitive ELISA for measuring ACE2 receptor binding of AH-bound antigen. Interestingly, after one month of 4°C storage, small increases in antigenicity with concomitant decreases in the ability to desorb the antigen from the AH were observed. Finally, we performed a comparability assessment of DCFHP antigen produced in Expi293 and CHO cells, which displayed expected differences in their N-linked oligosaccharide profiles. Despite consisting of different DCFHP glycoforms, these two preparations were highly similar in their key quality attributes including molecular size, structural integrity, conformational stability, binding to ACE2 receptor and mouse immunogenicity profiles. Taken together, these studies support future preclinical and clinical development of an AH-adjuvanted DCFHP vaccine candidate produced in CHO cells.

Hepatitis A: Viral Structure, Classification, Life Cycle, Clinical Symptoms, Diagnosis Error, and Vaccination

Hepatitis A virus (HAV) is one of the well-known viruses that cause hepatitis all around the globe. Although this illness has decreased in developed countries due to extensive immunization, numerous developing and under-developed countries are struggling with this virus. HAV infection can be spread by oral-fecal contact, and there are frequent epidemics through nutrition. Improvements in socioeconomic and sanitary circumstances have caused a shift in the disease's prevalence worldwide. Younger children are usually asymptomatic, but as they become older, the infection symptoms begin to appear. Symptoms range from slight inflammation and jaundice to acute liver failure in older individuals. While an acute infection may be self-limiting, unrecognized persistent infections, and the misapplication of therapeutic methods based on clinical guidelines are linked to a higher incidence of cirrhosis, hepatocellular carcinoma, and mortality. Fortunately, most patients recover within two months of infection, though 10-15% of patients will relapse within the first six months. A virus seldom leads to persistent infection or liver damage. The mainstay of therapy is based on supportive care. All children from 12-23 months, as well as some susceptible populations, should receive routine vaccinations, according to the Centers for Disease Control and Prevention and the American Academy of Pediatrics. Laboratory diagnosis of HAV is based on antigen detection, checking liver enzyme levels, and antibody screening. Furthermore, polymerase chain reaction (PCR) technology has identified HAV in suspected nutrition sources; therefore, this technique is used for preventative measures and food-related laws.

Overview of the global vaccine ecosystem

INTRODUCTION

Vaccination is an effective, relatively inexpensive, and easy to deliver approach to combating infectious diseases. Widespread vaccination of children has led to the eradication of smallpox and allowed for regional elimination or control of diseases like polio, measles, mumps, tetanus, diphtheria, and whooping cough. But, as we learned from efforts to combat the COVID-19 pandemic, a successful global vaccination program must overcome several hurdles. Failure at any stage can limit vaccine uptake and disease control.

AREAS COVERED

In this review, we break down the vaccine journey from research and development to delivery into several steps. We also list all the important international organizations trying to support this ecosystem. Then we identify the role of each of these organizations in supporting each of the necessary steps for a successful vaccination program.

EXPERT OPINION

The bottlenecks in vaccination can be different for different countries, based on their income and geography. Policy makers need to identify the weaknesses of this ecosystem in different regions of the world and make sure there is adequate global and local support to fill the gaps in the system.

Factors affecting willingness to participate in vaccine clinical trials in an underdeveloped country: perspective from Nepal

Due to the inherent complex nature of clinical trials, individual’s willingness to participate and hence, enrollment in a clinical trial maybe challenging. When it comes to vaccine clinical trial in children, informed consent needs to be secured from the parents or legally acceptable representatives (LARs). Some of the factors which contribute to hesitancy in taking part in clinical trials are based on the level of education, living standards, part of the world they live, associated burden of disease, fear of different procedures in clinical trial, side effects, limited understanding, limited time, and mistrust with Investigational product. This study included 201 parents/LARs, who approached Kanti Children Hospital site in Kathmandu with the interest to get their children enrolled in a vaccine clinical trial with objectives of describing the reasons for agreeing or disagreeing to participate in the vaccine clinical trial, factors affecting decision making, and finding the major concerns of parents/LARs. The acceptance for the study vaccine was 136 (67.7%) whereas denial was 65 (32.3%). This study showed that age, education level, family structure, advice from family and friends, and medical guidance play important roles in willingness of parents to get their child enrolled in the trial. If a proper counseling is done, fear of blood sampling is not a big factor which is contrary to the belief among clinical researchers. Safety of vaccine, frequency of injections, and cost of vaccine were the main concerns of the parents, which need to be addressed extensively while planning for any clinical trial in children.

Appraisal of SARS-CoV-2 mutations and their impact on vaccination efficacy: an overview

With the unexpected emergence of the novel 2019 Wuhan coronavirus, the world was faced with a sudden uproar that quickly shifted into a serious life-threatening pandemic. Affecting the lives of the global population and leaving drastic damage in various sections and systems, several measures have been constantly taken to tackle down this crisis. For instance, numerous vaccines have been developed in the past two years, some of which have been granted emergency use, thus providing sufficient immunity to the vaccinated individuals. However, the appearance of newly emerged SARS-CoV-2 variants with accelerated transmission and fatality has led the world towards another pandemic. Having undergone various mutations in genomic and/or amino acid profiles, some of the emerged variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta have displayed immune evasion and pathogenicity even in the vaccinated population, hence raising concerns regarding the efficacy of current vaccines against new VOCs of COVID-19. Therefore, genomic investigations of SARS-CoV-2 mutations are expected to provide valuable insight into the evolution of SARS-CoV-2, while also determining the impact of different mutations on infection severity. This study was constructed with the aim of shining light on recent advances regarding mutations in major COVID-19 VOCs, as well as vaccination efficacy against those VOCs.

A cost analysis of producing vaccines in developing countries

Developing country vaccine manufacturers (DCVMs) supply over half of the vaccines used in developing country immunisation programs. Decisions by developing countries to establish vaccine manufacturing should be based on economic viability, however reliable assessments of vaccine production costs are lacking. This study aimed to quantify the cost of establishing vaccine manufacturing facilities and producing vaccines in developing countries. This study estimates vaccine production costs in developing countries based on twelve vaccines produced by eight DCVMs. The results were based on estimates of the capital and operating costs required to establish vaccine manufacturing facilities under three hypothetical scenarios of production scale and scope. Cost patterns were then compared to vaccine prices paid by countries in both industrialized and developing country markets. The cost of producing vaccines in developing countries was estimated to be on average US$ 2.18 per dose, ranging between US$ 0.98 and US$ 4.85 for different vaccine types and formulations. Vaccine costs-per-dose decrease as production scale and scope increase. Cost-per-dose is mainly driven by fixed costs, but at a scale of production over 20 million doses per year it becomes driven by variable costs. Under the three hypothetical scenarios used, costs-per-dose of vaccines produced by developing countries were around 47% lower than vaccine prices in developing-country markets and 84% lower than prices in industrialized-country markets. This study has found that local production of vaccines in developing countries exhibits both economies of scale and economies of scope. The lower costs relative to prices suggests that a producer surplus and potential profits may be attainable in both developing and developed country markets, supporting sustainable production.

How far have we reached in development of effective influenza vaccine?

Despite of ongoing research programs and numerous clinical trials, seasonal influenza epidemics remain a major concern globally. Vaccination remains the most effective method to prevent influenza infection. However, current flu vaccines have several limitations, including limited vaccine capacity, long production times, inconsistence efficacy in certain populations, and lack of a "universal" solution. Different next-generation approaches such as cell line-based culture, reverse genetics, and virus expression technology are currently under development to address the aforementioned challenges in conventional vaccine manufacture pipeline. Such approaches hope for safe and scalable production, induce broad-spectrum immunity, create premade libraries of vaccine strains, and target nonvariable regions of antigenic proteins for "universal" vaccination. Here, we discuss the process and challenges of the current influenza vaccine platform as well as new approaches that are being investigated. These developments indicate that an exciting future lies ahead in the influenza vaccine field.

The complexity and cost of vaccine manufacturing - An overview

As companies, countries, and governments consider investments in vaccine production for routine immunization and outbreak response, understanding the complexity and cost drivers associated with vaccine production will help to inform business decisions. Leading multinational corporations have good understanding of the complex manufacturing processes, high technological and R&D barriers to entry, and the costs associated with vaccine production. However, decision makers in developing countries, donors and investors may not be aware of the factors that continue to limit the number of new manufacturers and have caused attrition and consolidation among existing manufacturers. This paper describes the processes and cost drivers in acquiring and maintaining licensure of childhood vaccines. In addition, when export is the goal, we describe the requirements to supply those vaccines at affordable prices to low-resource markets, including the process of World Health Organization (WHO) prequalification and supporting policy recommendation. By providing a generalized and consolidated view of these requirements we seek to build awareness in the global community of the benefits and costs associated with vaccine manufacturing and the challenges associated with maintaining consistent supply. We show that while vaccine manufacture may prima facie seem an economic growth opportunity, the complexity and high fixed costs of vaccine manufacturing limit potential profit. Further, for most lower and middle income countries a large majority of the equipment, personnel and consumables will need to be imported for years, further limiting benefits to the local economy.

Manufacturing DTaP-based combination vaccines: industrial challenges around essential public health tools

INTRODUCTION

The manufacture of DTP-backboned combination vaccines is complex, and vaccine quality is evaluated by both batch composition and conformance of manufacturing history. Since their first availability, both the manufacturing regulations for DTP combination vaccines and their demand have evolved significantly. This has resulted in a constant need to modify manufacturing and quality control processes. Areas covered: Regulations that govern the manufacture of complex vaccines can be inconsistent between countries and need to be aligned with the regulatory requirements that apply in all countries of distribution. Changes in product mix and quantities can lead to uncertainty in vaccine supply maintenance. These problems are discussed in the context of the importance of these products as essential public health tools. Expert commentary: Increasing demand for complex vaccines globally has led to problems in supply due to intrinsically complex manufacturing and regulatory procedures. Vaccine manufacturers are fully engaged in the resolution of these challenges, but currently changes in demand need ideally to be anticipated approximately 3 years in advance due to long production cycle times.