Clinical and regulatory development strategies for Shigella vaccines intended for children younger than 5 years in low-income and middle-income countries.

Shigellosis causes considerable public health burden, leading to excess deaths as well as acute and chronic consequences, particularly among children living in low-income and middle-income countries (LMICs). Several Shigella vaccine candidates are advancing in clinical trials and offer promise. Although multiple target populations might benefit from a Shigella vaccine, the primary strategic goal of WHO is to accelerate the development and accessibility of safe, effective, and affordable Shigella vaccines that reduce mortality and morbidity in children younger than 5 years living in LMICs. WHO consulted with regulators and policy makers at national, regional, and global levels to evaluate pathways that could accelerate regulatory approval in this priority population. Special consideration was given to surrogate efficacy biomarkers, the role of controlled human infection models, and the establishment of correlates of protection. A field efficacy study in children younger than 5 years in LMICs is needed to ensure introduction in this priority population.

Accelerating access for all through research and innovation in immunization: Recommendations from Strategic Priority 7 of the Immunization Agenda 2030.

Research and innovation have been fundamental to many of the successes in immunization thus far, and will play important roles in the future success of Immunization Agenda 2030 (IA2030). Strategic Priority 7 (SP7) of IA2030, which addresses research and innovation, is explicitly informed by country needs and priorities, and aims to strengthen the innovation ecosystem through capacity building and collaboration at country, regional, and global levels. SP7 identifies four key focus areas: (1) "needs-based innovation", (2) "new and improved products, services, and practices", (3) "evidence for implementation", and (4) "local capacity". Strategic interventions in these key focus areas apply the lessons of the Global Vaccine Action Plan and the "Decade of Vaccines" to emphasize local innovation, promote the use of research by countries to improve program performance and impact, and encourage capacity building for the development and implementation of innovations. The proposed approach will maintain a focus on the development of new vaccines and the improvement of existing vaccines, and increase attention to innovation in service delivery. Monitoring and evaluation will foster evidence-based priority setting at the country level and help to ground the global research and development (R&D) agenda in the needs of communities. Together, these approaches are intended to harness the power of research and innovation more effectively, to meet the challenges of the future and achieve the ambitious goals of IA2030.

Standardization of Epidemiological Surveillance of Invasive Group A Streptococcal Infections.

Invasive group A streptococcal (Strep A) infections occur when Streptococcus pyogenes, also known as beta-hemolytic group A Streptococcus, invades a normally sterile site in the body. This article provides guidelines for establishing surveillance for invasive Strep A infections. The primary objective of invasive Strep A surveillance is to monitor trends in rates of infection and determine the demographic and clinical characteristics of patients with laboratory-confirmed invasive Strep A infection, the age- and sex-specific incidence in the population of a defined geographic area, trends in risk factors, and the mortality rates and rates of nonfatal sequelae caused by invasive Strep A infections. This article includes clinical descriptions followed by case definitions, based on clinical and laboratory evidence, and case classifications (confirmed or probable, if applicable) for invasive Strep A infections and for 3 Strep A syndromes: streptococcal toxic shock syndrome, necrotizing fasciitis, and pregnancy-associated Strep A infection. Considerations of the type of surveillance are also presented, noting that most people who have invasive Strep A infections will present to hospital and that invasive Strep A is a notifiable disease in some countries. Minimal surveillance necessary for invasive Strep A infection is facility-based, passive surveillance. A resource-intensive but more informative approach is active case finding of laboratory-confirmed Strep A invasive infections among a large (eg, state-wide) and well defined population. Participant eligibility, surveillance population, and additional surveillance components such as the use of International Classification of Disease diagnosis codes, follow-up, period of surveillance, seasonality, and sample size are discussed. Finally, the core data elements to be collected on case report forms are presented.

Standardization of Epidemiological Surveillance of Group A Streptococcal Cellulitis.

Cellulitis is an acute bacterial infection of the dermis and subcutaneous tissue usually found complicating a wound, ulcer, or dermatosis. This article provides guidelines for the surveillance of cellulitis. The primary objectives of cellulitis surveillance are to (1) monitor trends in rates of infection, (2) describe the demographic and clinical characteristics of patients with cellulitis, (3) estimate the frequency of complications, and (4) describe the risk factors associated with primary and recurrent cellulitis. This article includes case definitions for clinical cellulitis and group A streptococcal cellulitis, based on clinical and laboratory evidence, and case classifications for an initial and recurrent case. It is expected that surveillance for cellulitis will be for all-cause cellulitis, rather than specifically for Strep A cellulitis. Considerations of the type of surveillance are also presented, including identification of data sources and surveillance type. Minimal surveillance necessary for cellulitis is facility-based, passive surveillance. Prospective, active, facility-based surveillance is recommended for estimates of pathogen-specific cellulitis burden. Participant eligibility, surveillance population, and additional surveillance considerations such as active follow-up of cases, the use of International Classification of Disease diagnosis codes, and microbiological sampling of cases are discussed. Finally, the core data elements to be collected on case report forms are presented.

Standardization of Epidemiological Surveillance of Acute Poststreptococcal Glomerulonephritis.

Acute poststreptococcal glomerulonephritis (APSGN) is an immune complex-induced glomerulonephritis that develops as a sequela of streptococcal infections. This article provides guidelines for the surveillance of APSGN due to group A Streptococcus (Strep A). The primary objectives of APSGN surveillance are to monitor trends in age- and sex-specific incidence, describe the demographic and clinical characteristics of patients with APSGN, document accompanying risk factors, then monitor trends in frequency of complications, illness duration, hospitalization rates, and mortality. This document provides surveillance case definitions for APSGN, including clinical and subclinical APSGN based on clinical and laboratory evidence. It also details case classifications that can be used to differentiate between confirmed and probable cases, and it discusses the current investigations used to provide evidence of antecedent Strep A infection. The type of surveillance recommended depends on the burden of APSGN in the community and the objectives of surveillance. Strategies for minimal surveillance and enhanced surveillance of APSGN are provided. Furthermore, a discussion covers the surveillance population and additional APSGN-specific surveillance considerations such as contact testing, active follow up of cases and contacts, frequency of reporting, surveillance visits, period of surveillance, and community engagement. Finally, the document presents core data elements to be collected on case report forms, along with guidance for documenting the course and severity of APSGN.

KSHV (HHV8) vaccine: promises and potential pitfalls for a new anti-cancer vaccine.

Seven viruses cause at least 15% of the total cancer burden. Viral cancers have been described as the "low-hanging fruit" that can be potentially prevented or treated by new vaccines that would alter the course of global human cancer. Kaposi sarcoma herpesvirus (KSHV or HHV8) is the sole cause of Kaposi sarcoma, which primarily afflicts resource-poor and socially marginalized populations. This review summarizes a recent NIH-sponsored workshop's findings on the epidemiology and biology of KSHV as an overlooked but potentially vaccine-preventable infection. The unique epidemiology of this virus provides opportunities to prevent its cancers if an effective, inexpensive, and well-tolerated vaccine can be developed and delivered.

Understanding the public health value and defining preferred product characteristics for therapeutic human papillomavirus (HPV) vaccines: World Health Organization consultations, October 2021-March 2022.

The World Health Organization (WHO) global strategy to eliminate cervical cancer (CxCa) could result in >62 million lives saved by 2120 if strategy targets are reached and maintained: 90% of adolescent girls receiving prophylactic human papillomavirus (HPV) vaccine, 70% of women receiving twice-lifetime cervical cancer screening, and 90% of cervical pre-cancer lesions and invasive CxCa treated. However, the cost and complexity of CxCa screening and treatment approaches has hampered scale-up, particularly in low- and middle-income countries (LMICs), and new approaches are needed. Therapeutic HPV vaccines (TxV), which could clear persistent high-risk HPV infection and/or cause regression of pre-cancerous lesions, are in early clinical development and might offer one such approach. During October 2021 to March 2022, WHO, in collaboration with the Bill and Melinda Gates Foundation, convened a series of global expert consultations to lay the groundwork for understanding the potential value of TxV in the context of current CxCa prevention efforts and for defining WHO preferred product characteristics (PPCs) for TxV. WHO PPCs describe preferences for vaccine attributes that would help optimize vaccine value and use in meeting the global public health need. This paper reports on the main discussion points and findings from the expert consultations. Experts identified several ways in which TxV might address challenges in current CxCa prevention programmes, but emphasized that the potential value of TxV will depend on their degree of efficacy and how quickly they can be developed and implemented relative to ongoing scale-up of existing interventions. Consultation participants also discussed potential use-cases for TxV, important PPC considerations (e.g., vaccine indications, target populations, and delivery strategies), and critical modelling needs for predicting TxV impact and cost-effectiveness.

Efforts to Develop Pfs25 Vaccines.

Acknowledging the fallibilities of recalling events from more than three decades ago, the recollection of Richard Carter's impact on the identification and development of Pfs25, a major surface protein of Plasmodium falciparum zygotes and ookinetes, and target of malaria transmission-blocking vaccines, remains unassailable. In fondest memories of Richard Carter's many contributions, herein retells some memorable events along the tortuous journey toward the development of Pfs25 vaccines.

A Systematic Framework for Prioritizing Burden of Disease Data Required for Vaccine Development and Implementation: The Case for Group A Streptococcal Diseases.

Vaccine development and implementation decisions need to be guided by accurate and robust burden of disease data. We developed an innovative systematic framework outlining the properties of such data that are needed to advance vaccine development and evaluation, and prioritize research and surveillance activities. We focus on 4 objectives-advocacy, regulatory oversight and licensure, policy and post-licensure evaluation, and post-licensure financing-and identify key stakeholders and specific requirements for burden of disease data aligned with each objective. We apply this framework to group A Streptococcus, a pathogen with an underrecognized global burden, and give specific examples pertinent to 8 clinical endpoints. This dynamic framework can be adapted for any disease with a vaccine in development and can be updated as vaccine candidates progress through clinical trials. This framework will also help with research and innovation priority setting of the Immunization Agenda 2030 (IA2030) and accelerate development of future vaccines.

WHO preferred product characteristics for monoclonal antibodies for passive immunization against respiratory syncytial virus (RSV) disease in infants - Key considerations for global use.

World Health Organization (WHO) preferred product characteristics describe preferences for product attributes that would help optimize value and use to address global public health needs, with a particular focus on low- and middle-income countries. Having previously published preferred product characteristics for both maternal and paediatric respiratory syncytial virus (RSV) vaccines, WHO recently published preferred product characteristics for monoclonal antibodies to prevent severe RSV disease in infants. This article summarizes the key attributes from the preferred product characteristics and discusses key considerations for future access and use of preventive RSV monoclonal antibodies.

Building the concept for WHO Evidence Considerations for Vaccine Policy (ECVP): Tuberculosis vaccines intended for adults and adolescents as a test case.

Currently, no formal mechanisms or systematic approaches exist to inform developers of new vaccines of the evidence anticipated to facilitate global policy recommendations, before a vaccine candidate approaches regulatory approval at the end of pre-licensure efficacy studies. Consequently, significant delays may result in vaccine introduction and uptake, while post-licensure data are generated to support a definitive policy decision. To address the uncertainties of the evidence-to-recommendation data needs and to mitigate the risk of delays between vaccine recommendation and use, WHO is evaluating the need for and value of a new strategic alignment tool: Evidence Considerations for Vaccine Policy (ECVP). EVCPs aim to fill a critical current gap by providing early (pre-phase 3 study design) information on the anticipated clinical trial and observational data or evidence that could support WHO and/or policy decision making for new vaccines in priority disease areas. The intent of ECVPs is to inform vaccine developers, funders, and other key stakeholders, facilitating stakeholder alignment in their strategic planning for late stage vaccine development. While ECVPs are envisaged as a tool to support dialogue on evidence needs between regulators and policy makers at the national, regional and global level, development of an ECVP will not preclude or supersede the independent WHO's Strategic Advisory Group of Experts on Immunization (SAGE) evidence to recommendation (EtR) process that is required for all vaccines seeking WHO policy recommendation. Tuberculosis (TB) vaccine candidates intended for use in the adolescent and adult target populations comprise a portfolio of priority vaccines in late-stage clinical development. As such, TB vaccines intended for use in this target population provide a 'test case' to further develop the ECVP concept, and develop the first WHO ECVP considerations guidance.

Achieving global equity for COVID-19 vaccines: Stronger international partnerships and greater advocacy and solidarity are needed.

Peter Figueroa and co-authors advocate for equity in the worldwide provision of COVID-19 vaccines.

Global public health security and justice for vaccines and therapeutics in the COVID-19 pandemic.

A Lancet Commission for COVID-19 task force is shaping recommendations to achieve vaccine and therapeutics access, justice, and equity. This includes ensuring safety and effectiveness harmonized through robust systems of global pharmacovigilance and surveillance. Global production requires expanding support for development, manufacture, testing, and distribution of vaccines and therapeutics to low- and middle-income countries (LMICs). Global intellectual property rules must not stand in the way of research, production, technology transfer, or equitable access to essential health tools, and in context of pandemics to achieve increased manufacturing without discouraging innovation. Global governance around product quality requires channelling widely distributed vaccines through WHO prequalification (PQ)/emergency use listing (EUL) mechanisms and greater use of national regulatory authorities. A World Health Assembly (WHA) resolution would facilitate improvements and consistency in quality control and assurances. Global health systems require implementing steps to strengthen national systems for controlling COVID-19 and for influenza vaccinations for adults including pregnant and lactating women. A collaborative research network should strive to establish open access databases for bioinformatic analyses, together with programs directed at human capacity utilization and strengthening. Combating anti-science recognizes the urgency for countermeasures to address a global-wide disinformation movement dominating the internet and infiltrating parliaments and local governments.

Evolving pharmacovigilance requirements with novel vaccines and vaccine components.

This paper explores the pipeline of new and upcoming vaccines as it relates to monitoring their safety. Compared with most currently available vaccines, that are constituted of live attenuated organisms or inactive products, future vaccines will also be based on new technologies. Several products that include such technologies are either already licensed or at an advanced stage of clinical development. Those include viral vectors, genetically attenuated live organisms, nucleic acid vaccines, novel adjuvants, increased number of antigens present in a single vaccine, novel mode of vaccine administration and thermostabilisation. The Global Advisory Committee on Vaccine Safety (GACVS) monitors novel vaccines, from the time they become available for large scale use. GACVS maintains their safety profile as evidence emerges from post-licensure surveillance and observational studies. Vaccines and vaccine formulations produced with novel technologies will have different safety profiles that will require adapting pharmacovigilance approaches. For example, GACVS now considers viral vector templates developed on the model proposed by Brighton Collaboration. The characteristics of those novel products will also have implications for the risk management plans (RMPs). Questions related to the duration of active monitoring for genetic material, presence of adventitious agents more easily detected with enhanced biological screening, or physiological mechanisms of novel adjuvants are all considerations that will belong to the preparation of RMPs. In addition to assessing those novel products and advising experts, GACVS will also consider how to more broadly communicate about risk assessment, so vaccine users can also benefit from the committee's advice.

Force of infection: a determinant of vaccine efficacy?

Vaccine efficacy (VE) can vary in different settings. Of the many proposed setting-dependent determinants of VE, force of infection (FoI) stands out as one of the most direct, proximate, and actionable. As highlighted by the COVID-19 pandemic, modifying FoI through non-pharmaceutical interventions (NPIs) use can significantly contribute to controlling transmission and reducing disease incidence and severity absent highly effective pharmaceutical interventions, such as vaccines. Given that NPIs reduce the FoI, the question arises as to if and to what degree FoI, and by extension NPIs, can modify VE, and more practically, as vaccines become available for a pathogen, whether and which NPIs should continue to be used in conjunction with vaccines to optimize controlling transmission and reducing disease incidence and severity.

Pregnant women & vaccines against emerging epidemic threats: Ethics guidance for preparedness, research, and response.

Zika virus, influenza, and Ebola have called attention to the ways in which infectious disease outbreaks can severely - and at times uniquely - affect the health interests of pregnant women and their offspring. These examples also highlight the critical need to proactively consider pregnant women and their offspring in vaccine research and response efforts to combat emerging and re-emerging infectious diseases. Historically, pregnant women and their offspring have been largely excluded from research agendas and investment strategies for vaccines against epidemic threats, which in turn can lead to exclusion from future vaccine campaigns amidst outbreaks. This state of affairs is profoundly unjust to pregnant women and their offspring, and deeply problematic from the standpoint of public health. To ensure that the needs of pregnant women and their offspring are fairly addressed, new approaches to public health preparedness, vaccine research and development, and vaccine delivery are required. This Guidance offers 22 concrete recommendations that provide a roadmap for the ethically responsible, socially just, and respectful inclusion of the interests of pregnant women in the development and deployment of vaccines against emerging pathogens. The Guidance was developed by the Pregnancy Research Ethics for Vaccines, Epidemics, and New Technologies (PREVENT) Working Group - a multidisciplinary, international team of 17 experts specializing in bioethics, maternal immunization, maternal-fetal medicine, obstetrics, pediatrics, philosophy, public health, and vaccine research and policy - in consultation with a variety of external experts and stakeholders.