Probability of Success and Timelines for the Development of Vaccines for Emerging and Reemerged Viral Infectious Diseases

The role of the right valuation method in setting the firm's break-even price for mpox (and other) vaccines

Critical voices on unfairly high mpox and other vaccine prices open the debate on the 'right price' to be paid to private vaccine suppliers. We apply compound real options analysis as a more appropriate valuation method to derive a correct firm's break-even price. Real option models are better able to capture the development costs, associated risks and the embedded operational flexibility in vaccine development in a superior way compared with more traditional net present value (NPV) methods. The real option price is lower than standard NPV-based methods, thereby providing a basis to improve the bargaining position of payers in negotiating better vaccine price outcomes. Deeper insights into the correct break-even price will create a more balanced playing field between firms and payers. This can also lead to more equitable access to vaccines in developing countries.

Populations Addressed in Vaccines Approved via the European Medicines Agency

Therapeutic and prophylactic agents require robust evidence before patient use. Randomized controlled trials are essential for evaluating safety and efficacy but often exclude specific populations that are also targets for the intervention. This study assessed which populations are included in vaccine registration studies and/or addressed in label indications, and if special populations are considered at any point in the regulatory life cycle of vaccines approved in the European Union. We analyzed product labels, pivotal studies, risk management plans, and post-authorization studies for all vaccines centrally approved via the European Medicines Agency between 2012 and 2022. For the 31 vaccines approved, we identified 90 pivotal studies supporting initial marketing authorizations and 46 studies supporting product revisions. At the end of our follow-up, 27 vaccines (87%) were approved for adults, 19 (68%) for pediatric patients, 3 (11%) were recommended for pregnant populations, 4 (14%) for breastfeeding populations, and 7 (23%) for immunocompromised populations. Pregnant, breastfeeding, and immunocompromised individuals were rarely included in studies supporting regulatory actions. We observed a slight increase in the inclusion of special populations in post-marketing studies, yet this had limited impact on product indications or information availability on labels. Pivotal studies supporting vaccine registrations were also highly selective and predominantly conducted in high-income settings. These findings highlight significant variations in how different populations are considered during vaccine development and by regulators. Greater inclusion of special populations in the evidence-generation chain is essential to ensure that vaccines respond to unmet medical needs equitably.

Human Challenge Studies with Coronaviruses Old and New

Coronavirus infections have been known to cause disease in animals since as early as the 1920s. However, only seven coronaviruses capable of causing human disease have been identified thus far. These Human Coronaviruses (HCoVs) include the causes of the common cold, but more recent coronaviruses that have emerged (i.e. SARS-CoV, MERS-CoV and SARS-CoV-2) are associated with much greater morbidity and mortality. HCoVs have been relatively under-studied compared to other common respiratory infections, as historically they have presented with mild symptoms. This has led to a relatively limited understanding of their animal reservoirs, transmission and determinants of immune protection. To address this, human infection challenge studies with HCoVs have been performed that enable a detailed clinical and immunological analysis of the host response at specific time points under controlled conditions with standardised viral inocula. Until recently, all such human challenge studies were conducted with common cold HCoVs, with the study of SARS-CoV and MERS-CoV unacceptable due to their greater pathogenicity. However, with the emergence of SARS-CoV-2 and the COVID-19 pandemic during which severe outcomes in young healthy adults have been rare, human challenge studies with SARS-CoV-2 are now being developed. Two SARS-CoV-2 human challenge studies in the UK studying individuals with and without pre-existing immunity are underway. As well as providing a platform for testing of antivirals and vaccines, such studies will be critical for understanding the factors associated with susceptibility to SARS-CoV-2 infection and thus developing improved strategies to tackle the current as well as future HCoV pandemics. Here, we summarise the major questions about protection and pathogenesis in HCoV infection that human infection challenge studies have attempted to answer historically, as well as the knowledge gaps that aim to be addressed with contemporary models.

Assessment of the COVID-19 vaccine market landscape in 2021 relative to challenges in low- and middle-income countries

To evaluate the early vaccine landscape relative to challenges faced by low- and middle-income countries (LMIC), we conducted a cross-sectional study of all COVID-19 vaccines in clinical trials in 2021 (n = 123) using a structured 13-point analytic framework. Supply sustainability was defined as a composite metric of four manufacturing and regulation variables. Vaccine desirability was defined as a composite metric of nine development and distribution variables. Ten vaccines in phases 2/3, 3, or 4 and five vaccines in phases 1 and 1/2 had a sustainability score equal to or above 0.5. Ten vaccines in phases 2/3, 3, or 4 and seven vaccines in phases 1 and 1/2 had a desirability score equal to or above 0.5. No vaccines in Phases 2/3, 3, or 4 met more than one distribution criterion. Structured assessment COVID-19 vaccine candidates in clinical trials in 2021 revealed numerous challenges to adequate access in LMICs. Key policy recommendations included increasing technology transfer to LMICs, developing international legal mechanisms to prevent export bans, and increasing investment in vaccine candidates with more favorable distribution profiles.

Physical radiofrequency adjuvant enhances immune responses to influenza H5N1 vaccination

Pre-pandemic influenza H5N1 vaccine has relatively low immunogenicity and often requires high antigen amounts and two immunizations to induce protective immunity. Incorporation of vaccine adjuvants is promising to stretch vaccine doses during pandemic outbreaks. This study presents a physical radiofrequency (RF) adjuvant (RFA) to conveniently and effectively increase the immunogenicity and efficacy of H5N1 vaccine without modification of vaccine preparation. Physical RFA is based on a brief RF treatment of the skin to induce thermal stress to enhance intradermal vaccine-induced immune responses with minimal local or systemic adverse reactions. We found that physical RFA could significantly increase H5N1 vaccine-induced hemagglutination inhibition antibody titers in murine models. Intradermal H5N1 vaccine in the presence of RFA but not vaccine alone significantly lowered lung viral titers, reduced body weight loss, and improved survival rates after lethal viral challenges. The improved protection in the presence of RFA was correlated with enhanced humoral and cellular immune responses to H5N1 vaccination in both male and female mice, indicating no gender difference of RFA effects in murine models. Our data support further development of the physical RFA to conveniently enhance the efficacy of H5N1 vaccine.

Combating the Current Pandemic and Preparing for the Next: Lessons Learned From the COVID-19 Pandemic From the Perspective of Deployed Special Operations Forces

The coronavirus 2019 (COVID-19) pandemic continues to be a threat to global health, including the health of deployed armed forces. Servicemembers had to adjust to the “new normal” while maintaining the interests of the nation’s security as well as that of our host nation partners. This commentary examines how Special Operations Forces operating within four different regions worldwide leveraged the challenges presented by the onset of this pandemic in maintaining stability, sustaining a ready force, and operating forward deployed. Deployed forces face constant difficulties with logistical support, varied medical resources access and a medical system predominantly focused on trauma care. At the onset of the COVID-19 pandemic there was little guidance specific to these circumstances which required an improvised adaptation of the recommendations set by national and Department of Defense medical authorities. Plans were constantly revised to match the ever changing medical and operational environment. Strategies such as the “Bubble Philosophy” and tiered force protection measures helped our units to maintain a rigorous training cycle. New methods of communication and training with our host nation partners such as the use of Unmanned Aerial Systems (UAS) platforms to survey host nation training became standard. Through these measures all of our forces were able to maintain operational capacity, protect the force, and maintain rapport with the host nations. We hope these experiences will provide a rough framework for future forces faced with a similar struggle. We also want to stress that challenges vary depending on the area of operations and the pathogen responsible for the pandemic. Any feedback and collaboration that may come from this work is appreciated and encouraged.

Healthcare Providers’ Perspectives Toward the Integration of over the Counter Supplements During COVID-19 Pandemic: A Cross-Sectional Study from Jordan

Objective: During COVID-19 pandemic, healthcare providers (HCPs) have been inundated with consultations related to over the counter (OTC) dietary supplements’ protective role. Thus, the present study focused on assessing HCPs perceptions toward OTC products integration during the COVID-19 outbreak. Methods: Pertinent data was collected using validated-online survey comprising four sections: demographics, OTC supplementation perceptions, awareness related to safety of OTC supplements, confidence in recommending dosage and counseling to patients regarding OTC supplements’ safety, and some health-related behaviors. Quantified perception score represented by corrected confidence-concern ratio was used in assessing perceptions, and associations between demographics with perception and awareness were explored. Results: A total of 600 responses were included in the final analysis. Vitamin C, zinc, and vitamin D were the most popularly recommended OTC supplements. Most respondents indicated positive perceptions toward dietary supplementation while around 60% of respondents reported reluctance about the protective role of COVID-19 vaccination. Bachelor’s degree holders (AOR = 4.39, 95% CI = 2.25–10.33), pharmacists (AOR = 2.17, 95% CI = 1.5–9.5), and junior HCPs (<1 year experience) had improved perceptions compared to college graduates, physicians, and senior practitioners (AOR = .17, 95% CI = .04–.78 and AOR = .15, 95% CI = .02–.93), respectively. Conclusion: Suboptimal knowledge among HCPs toward the safety and hazards associated with integration of different OTC supplements during the COVID-19 pandemic dictates further education to ensure the safe integration of OTC supplements.

Antibiotic prescribing patterns for childhood infections in ambulatory settings in Jordan

BACKGROUND

Antibiotics' rational prescribing is a major goal of the World Health Organization's (WHO) global action plan to tackle antimicrobial resistance. Evaluation of antibiotic prescribing patterns is necessary to guide simple, globally applicable stewardship interventions. The impact of antimicrobial resistance is devastating, especially in low-income countries. We aimed to introduce ambulatory data on patterns of paediatric antibiotic prescribing in Jordan, which could be used to guide local stewardship interventions.

METHODS

A cross-sectional retrospective study was conducted by selecting a random sample of paediatric patients, who attended ambulatory settings in 2018. Records of outpatients (age ≤18 years) receiving at least one antibiotic were included. The WHO's model of drug utilisation was applied, and all prescribing indicators were included. Multiple linear regression was performed to examine factors influencing the ratio of prescribed antibiotics to overall medications per encounter.

RESULTS

A total of 20 494 prescriptions, containing 45 241 prescribed drugs, were obtained. The average number of prescribed drugs per prescription was (2.21 ± 0.98). Approximately 77.5% of overall ambulatory prescriptions accounted for antimicrobials. Only 0.6% of total prescriptions were for injectables. All antimicrobials (100%) were prescribed by generic names and from the essential drug list. Antibiotics were most commonly prescribed for respiratory tract infections. Age, gender, season and facility type were significant predictors of prescribed antibiotics to overall medications ratio.

CONCLUSIONS

This is the first study of antibiotic prescribing patterns among outpatient paediatrics that covers wide regions in Jordan. Results indicate high rates of antibiotics use among outpatient paediatrics. Such findings necessitate more focussed efforts and regulations that support rational utilisation of drugs.

3D printing technologies for in vitro vaccine testing platforms and vaccine delivery systems against infectious diseases

Recent advances in 3D printing (3DP) and tissue engineering approaches enable the potential application of these technologies to vaccine research. Reconstituting the native tissue or cellular microenvironment will be vital for successful evaluation of pathogenicity of viral infection and screening of potential vaccines. Therefore, establishing a reliable in vitro model to study the vaccine efficiency or delivery of viral disease is important. Here, this review summarizes two major ways that tissue engineering and 3DP strategies could contribute to vaccine research: (1) 3D human tissue models to study the response to virus can be served as a testbed for new potential therapeutics. Using 3D tissue platform attempts to explore alternative options to pre-clinical animal research for evaluating vaccine candidates. (2) 3DP technologies can be applied to improve the vaccination strategies which could replace existing vaccine delivery. Controlled antigen release using carriers that are generated with biodegradable biomaterials can further enhance the efficient development of immunity as well as combination of multiple-dose vaccines into a single injection. This mini review discusses the up-to-date report of current 3D tissue/organ models for potential vaccine potency and known bioengineered vaccine delivery systems.