Philipp Lambach

Even though two widely used combination vaccines (measles-rubella- and diphtheria- tetanus-pertussis-containing vaccines) are universally acknowledged as the cornerstones of pediatric immunization programs, the development of new combination vaccines for children has not been a priority for manufacturers, policy bodies, or decision-makers. At the same time, economic evaluations have not assessed the full array of benefits and risks associated with combination vaccines. As part of an effort to identify and prioritize potential new combination vaccines, we aimed to enhance efforts to establish their value, a crucial step toward a more thorough, quantifiable, and realistic assessment of these vaccines.We reviewed the literature on economic evaluations of combination vaccines to more precisely identify and define current gaps in value assessment. We identified a set of (often unvalued) benefits and risks and created a list of value drivers and metrics for potential inclusion in future evaluations. Value drivers were then categorized based on how they resonate with decision-makers’ priorities and their contribution to product value. Metrics were categorized based on their quantifiability and their fit within existing economic evaluation frameworks. We developed a prioritized checklist of value drivers and metrics to assess combination vaccines through a consultative process involving numerous immunization stakeholders (e.g., immunization specialists, regional immunization advisors, policy bodies). The checklist was further refined through a convening of health economics experts and ultimately endorsed by the World Health Organization’s Immunization and Vaccines-related Implementation Research Advisory Committee.This checklist of prioritized value drivers and metrics is meant to serve as a tool for analysts to value combination vaccines and help ensure these vaccines are more comprehensively assessed by decision-makers to inform investment decisions or adoption.

Background: Next-generation influenza vaccines have the potential to overcome the limitations of current seasonal influenza vaccines by providing more efficacious, broader, and longer-lasting protection and enhanced pandemic preparedness. However, their development is constrained by regulatory, financial, and scientific challenges. This study aimed to better understand these barriers and enablers from the perspective of vaccine developers. Methods: We employed a mixed-methods approach, collecting data through an online survey and follow-up interviews with 17 developers engaged in next-generation influenza vaccine R&D. Thematic analysis was used to identify key scientific, regulatory, and financial challenges, enablers and priorities for advancing development. Results: Developers reported a range of scientific and regulatory challenges, particularly the lack of established correlates of protection and uncertainty around evaluation criteria for novel platforms. High development costs and limited access to sustained funding were consistently cited as key barriers. Developers emphasized the need for clearer regulatory guidance, harmonized approval pathways, and validation of alternative immune markers. Collaborative approaches, including partnerships, consortia, and trial networks, emerged as critical enablers. Most respondents also reported leveraging their influenza vaccine R&D to support COVID-19 vaccine development, underscoring their relevance to broader pandemic preparedness. Conclusions: Next-generation influenza vaccines have the potential to significantly improve both seasonal influenza control and pandemic response. Realizing this potential requires coordinated action to address scientific, regulatory, and financial hurdles. Investment in regulatory innovation, sustainable financing, and collaborative R&D platforms will be essential to accelerate progress and ensure global access to improved influenza vaccines.

For response to an outbreak of Ebola Virus Disease (EVD), the World Health Organisation (WHO) guidelines recommend vaccination of any contacts and contacts-of-contacts of identified EVD cases, also known as ring vaccination. However this standard response can be challenging to implement in remote regions or conflict zones. In recent outbreaks, response efforts have also tried blanket vaccination in the immediate vicinity of the homes and workplaces of identified cases, also known as geographically targeted vaccination. The relative effectiveness of these deployment strategies is difficult to study empirically, and modelling work to date has been limited. In this study, we use a spatially explicit individual-based stochastic simulation to model an EVD epidemic and public health response using either ring or geographically targeted vaccination alongside standard response activities. We explore a wide range of outbreak scenarios and response levels. Overall, we find little difference between ring or geographically targeted vaccination for either health or cost outcomes; the quality of surveillance and effectiveness of standard response activities are much larger drivers. However, vaccination does provide incremental benefit in combination with those activities, and the preferred strategy changes depending how well non-pharmaceutical activities are executed. Ring vaccination provides more incremental benefit on top of otherwise effective response activities (e.g. rapid and high ascertainment of contacts) but geographically targeted vaccination is better when those activities are less effectively delivered. These findings are relevant to policy makers deciding how to most effectively and cost-effectively deploy EVD vaccines in resource-limited and often challenging outbreak settings.

Background/Objective: Historically, immunization programs have focused on infants, children, and women of reproductive age. COVID-19 vaccination prompted countries to vaccinate adults. The objective of this manuscript is to provide a global overview of adult immunization policies post COVID-19 pandemic. Methods: We summarized WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations by adult group and analyzed the data reported in 2024 (2023) by WHO Member States (MS) via the WHO/UNICEF electronic Joint Reporting Form on Immunization (eJRF) on national immunization schedules, and from other sources by WHO region and income group. Results: WHO policy recommendations exist for most of the licensed vaccines targeting adults; however, the inclusion in national immunization schedules is higher in high-income (HICs) and middle-income (MICs) countries. For pregnant women, 90% of MS reported vaccination against COVID-19 (65% in low-income countries [LICs]), 63% against tetanus-containing vaccines (73% in LICs), 57% against influenza (4% in LICs), and 21% against pertussis-containing vaccines (all MICs and HICs). For health workers, 91% against COVID-19 (92% in LICs), 59% against influenza (4% in LICs), and 25% against hepatitis B (10% in LICs). For adults with chronic diseases, COVID-19 vaccination data were not available, 58% against influenza, and 23% against pneumococcal disease. For older adults, more than 90% of MS across all income groups reported COVID-19 vaccination, 59% against influenza (8% of LICs versus 89% of HICs), 17% against pneumococcal, and 7% against herpes zoster (HZ). Conclusion: The disparities in adult immunization policies across income groups highlight the need to improve access and strengthen vaccination efforts. A life course approach is essential to maximize the full potential of immunization across all ages.

Background: Historically, immunization programmes have focused on infants, children, and women of reproductive age. COVID-19 vaccination prompted countries to vaccinate adults. This manuscript provides a global overview of adult immunization post COVID-19 pandemic. Methods: We summarized WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations by adult group and analyzed the data reported in 2024 (2023) by WHO Member States (MS) via the WHO/UNICEF electronic Joint Reporting Form on Immunization (eJRF) on national immunization schedules, and from other sources by WHO region and income group. Results: WHO policy recommendations exist for most of the licensed vaccines targeting adults; however, the inclusion in national immunization schedules is higher in high-income (HICs) and middle-income (MICs) countries. For pregnant women, 90% of MS reported vaccination against COVID-19 (65% in low-income countries [LICs]), 63% against tetanus-containing vaccines (73% in LICs), 57% against influenza (4% in LICs), and 21% against pertussis-containing vaccines (all MICs and HICs). For health workers, 91% against COVID-19 (92% in LICs), 59% against influenza (4% in LICs), and 25% against hepatitis B (10% in LICs). For adults with chronic diseases, COVID-19 vaccination data were not available, 58% against influenza, and 23% against pneumococcal disease. For older adults, more than 90% of MS across all income groups reported COVID-19 vaccination, 59% against influenza (8% of LICs versus 89% of HICs), 17% against pneumococcal, and 7% against herpes zoster. Conclusion: The disparities in adult immunization policies across income groups highlight the need to improve access and strengthen vaccination efforts. A life course approach is essential to maximize the full potential of immunization across all ages.

Vaccination is the most effective way to prevent influenza infection and adverse outcomes; despite global recommendations to vaccinate pregnant persons, access to influenza vaccines remains low. We explored knowledge, attitudes, and practices of pregnant persons to inform actions to improve vaccine uptake. We pooled data from cross-sectional surveys assessing pregnant persons’ attitudes toward influenza vaccines in 8 low- and middle-income countries. Countries used standard methods to measure attitudes and intents toward influenza vaccination. We stratified by presence/absence of a national influenza vaccination program, income group, geographic region, and individual-level factors. Our analysis included 8556 pregnant persons from 8 countries. Most pregnant persons (6323, 74%) were willing to receive influenza vaccine if it was offered for free. Willingness differed by presence of an existing influenza vaccination program; acceptance was higher in countries without programs (2383, 89%) than in those with programs (3940, 67%, P < .001). Most pregnant persons in middle-income countries, regardless of influenza vaccination program status, were willing to be vaccinated against influenza if the vaccine was provided free of charge. National investments in influenza vaccination programs present an opportunity to avert illness both in pregnant persons themselves and in their newborn babies.

For vaccine development and adoption decisions, the ‘Full Value of Vaccine Assessment’ (FVVA) framework has been proposed by the WHO to expand the range of evidence available to support the prioritization of candidate vaccines for investment and eventual uptake by low- and middle-income countries. Recent applications of the FVVA framework have already shown benefits. Building on the success of these applications, we see important new opportunities to maximize the future utility of FVVAs to country and global stakeholders and provide a proof-of-concept for analyses in other areas of disease control and prevention. These opportunities include the following: (1) FVVA producers should aim to create evidence that explicitly meets the needs of multiple key FVVA consumers, (2) the WHO and other key stakeholders should develop standardized methodologies for FVVAs, as well as guidance for how different stakeholders can explicitly reflect their values within the FVVA framework, and (3) the WHO should convene experts to further develop and prioritize the research agenda for outcomes and benefits relevant to the FVVA and elucidate methodological approaches and opportunities for standardization not only for less well-established benefits, but also for any relevant research gaps. We encourage FVVA stakeholders to engage with these opportunities.

To ensure that limited domestic resources are invested in the most effective interventions, immunization programs in low- and middle-income countries (LMICs) must prioritize a growing number of new vaccines while considering opportunities to optimize the vaccine portfolio, as well as other components of the health system. There is a strong impetus for immunization decision-making to engage and coordinate various stakeholders across the health system in prioritization. To address this, national immunization program decision-makers in LMICs collaborated with WHO to structure deliberation among stakeholders and document an evidence-based, context-specific, and transparent process for prioritization or selection among multiple vaccination products, services, or strategies. The output of this effort is the Country-led Assessment for Prioritization on Immunization (CAPACITI) decision-support tool, which supports using multiple criteria and stakeholder perspectives to evaluate trade-offs affecting health interventions, taking into account variable data quality. Here, we describe the user feedback from Indonesia and Ethiopia, two initial countries that piloted the CAPACITI decision-support tool, highlighting enabling and constraining factors. Potential immunization program benefits and lessons learned are also summarized for consideration in other settings.

Somalia is a complex and fragile setting with a demonstrated potential for disruptive, high-burden measles outbreaks. In response, since 2018, Somalian authorities have partnered with UNICEF and the WHO to implement measles vaccination campaigns across the country. In this paper, we create a Somalia-specific model of measles transmission based on a comprehensive epidemiological dataset including case-based surveillance, vaccine registries, and serological surveys. We use this model to assess the impact of these campaign interventions on Somalian’s measles susceptibility, showing, for example, that across the roughly 10 million doses delivered, 1 of every 5 immunized a susceptible child. Finally, we use the model to explore a counter-factual epidemiology without the 2019–2020 campaigns, and we estimate that those interventions prevented over 10,000 deaths.