Archetype analysis of older adult immunization decision-making and implementation in 34 countries

Invasive meningococcal disease in older adults: current perspectives and call for action

PURPOSE

Invasive meningococcal disease (IMD) is a devastating condition. While most attention is directed towards disease in children and adolescents, IMD poses an important cause of morbidity and mortality in adults ≥60 years. While immunization is a critical component of healthy ageing strategies, meningococcal immunization is not routinely offered to older adults. The aim of this review was to summarize clinical and epidemiological aspects of IMD and available immunization strategies, with a particular focus on disease in older individuals, to emphasize the importance of this rather neglected area.

METHODS

An expert working group was established to evaluate clinical and epidemiological data to raise awareness of IMD in older individuals, and develop suggestions to improve the existing burden.

RESULTS

Routine child and adolescent meningococcal immunization has substantially reduced IMD in these targeted populations. Consequently, prevalence and proportion of IMD among those ≥60 years, mostly unvaccinated, is increasing in developed countries (accounting for up to 25% of cases). IMD-related mortality is highest in this age-group, with substantial sequelae in survivors. IMD due to serogroups W and Y is more prevalent among older adults, often with atypical clinical features (pneumonia, gastrointestinal presentations) which may delay timely treatment.

CONCLUSIONS

IMD in older adults remains overlooked and greater awareness is required at clinical and societal levels. We encourage clinicians and immunization policy makers to reconsider IMD, with a call for action to remedy existing inequity in older adult access to protective meningococcal immunization.

Identifying factors that can be used to assess a country's readiness to deploy a new vaccine or improve uptake of an underutilised vaccine: a scoping review

OBJECTIVES

Identifying whether a country is ready to deploy a new vaccine or improve uptake of an existing vaccine requires knowledge of a diverse range of interdependent, context-specific factors. This scoping review aims to identify common themes that emerge across articles, which include tools or guidance that can be used to establish whether a country is ready to deploy a new vaccine or increase uptake of an underutilised vaccine.

DESIGN

Scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines.

DATA SOURCES

Embase, CINAHL, Cochrane Library, Google Scholar, MEDLINE, PsycINFO and Web of Science were searched for articles published until 9 September 2023. Relevant articles were also identified through expert opinion.

ELIGIBILITY CRITERIA

Articles published in any year or language that included tools or guidance to identify factors that influence a country's readiness to deploy a new or underutilised vaccine.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers screened records and performed data extraction. Findings were synthesised by conducting a thematic analysis.

RESULTS

38 articles met our inclusion criteria; these documents were created using methodologies including expert review panels and Delphi surveys and varied in terms of content and context-of-use. 12 common themes were identified relevant to a country's readiness to deploy a new or underutilised vaccine. These themes were as follows: (1) legal, political and professional consensus; (2) sociocultural factors and communication; (3) policy, guidelines and regulations; (4) financing; (5) vaccine characteristics and supply logistics; (6) programme planning; (7) programme monitoring and evaluation; (8) sustainable and integrated healthcare provision; (9) safety surveillance and reporting; (10) disease burden and characteristics; (11) vaccination equity and (12) human resources and training of professionals.

CONCLUSIONS

This information has the potential to form the basis of a globally applicable evidence-based vaccine readiness assessment tool that can inform policy and immunisation programme decision-makers.

Leaving no one behind: Defining and implementing an integrated life course approach to vaccination across the next decade as part of the immunization Agenda 2030

Strategic Priority 4 (SP4) of the Immunization Agenda 2030 aims to ensure that all people benefit from recommended immunizations throughout the life-course, integrated with essential health services. Therefore, it is necessary for immunization programs to have coordination and collaboration across all health programs. Although there has been progress, immunization platforms in the second year of life and beyond need continued strengthening, including booster doses and catch-up vaccination, for all ages, and recommended vaccines for older age groups. We note gaps in current vaccination programs policies and achieved coverage, in the second year of life and beyond. In 2021, the second dose of measles-containing vaccine (MCV2), given in the second year of life, achieved 71% global coverage vs 81% for MCV1. For adolescents, 60% of all countries have adopted human papillomavirus vaccines in their vaccination schedule with a global coverage rate of only 12 percent in 2021. Approximately 65% of the countries recommend influenza vaccines for older adults, high-risk adults and pregnant women, and only 25% recommended pneumococcal vaccines for older adults. To achieve an integrated life course approach to vaccination, we reviewed the evidence, gaps, and strategies in four focus areas: generating evidence for disease burden and potential vaccine impact in older age groups; building awareness and shifting policy beyond early childhood; building integrated delivery approaches throughout the life course; and identifying missed opportunities for vaccination, implementing catch-up strategies, and monitoring vaccination throughout the life course. We identified needs, such as tailoring strategies to the local context, conducting research and advocacy to mobilize resources and build political will. Mustering sufficient financial support and demand for an integrated life course approach to vaccination, particularly in times of COVID-19, is both a challenge and an opportunity.

Socioeconomic and fiscal returns of expanded investment in immunization: a case for life-course vaccination in Colombia

Despite the health, societal, and economic benefits of immunization, many countries focus primarily on childhood immunizations and lack robust policies and sufficient resources for immunizations that can benefit populations across the life course. While the benefits of childhood vaccination are well documented, there is limited evidence on the financial and social return on investment that policymakers can use to inform decisions around administering a life-course immunization program. We developed a cost-benefit model from a societal perspective to evaluate the inclusion of 5 vaccines across the life course in Colombia's national immunization program. This model estimated a return of US$1.3 per US$1.0 invested in the first 2 decades, increasing to US$3.9 after 60 years. Primary benefits were productivity gains, followed by fiscal savings and household averted expenditure on health care. Furthermore, vulnerable households are predicted to receive 3.2 times greater income protection than formally employed households under a life-course immunization program. Consequently, there is a potential to reduce Colombia's income inequality and poverty rate by increasing access to immunization for all ages.

Assessment of the comprehensiveness of paediatric national immunisation programmes in Europe: expert validation and future perspectives

BACKGROUND

The breadth of protection of National Immunisation Programmes (NIPs) across Europe varies, however, this has not been assessed within published literature. Therefore, a framework was developed to assess the comprehensiveness of pediatric NIPs in Europe. This study aimed to validate and further develop criteria used to cluster countries into three tiers.

RESEARCH DESIGN AND METHODS

Independent Europe-based experts (n = 23) in the field of pediatric vaccination were invited to participate in a double-blinded modified Delphi panel, with two online survey rounds and a virtual consensus meeting. Consensus was defined as ≥ 80% of experts rating their agreement/disagreement on a 9-point Likert scale.

RESULTS

The number of preventable diseases covered by an NIP, simplification of the vaccination calendar, strengthened protection by increasing serotype, degree of funding and epidemiological factors were considered key concepts for consideration of the comprehensiveness of pediatric NIPs in Europe. Experts highlighted that the framework should be extended to include adolescent vaccines and populations up to 18 years of age. Consensus regarding further amendments to the framework was also reached.

CONCLUSIONS

This Delphi panel validated a framework to assess the comprehensiveness of European NIPs. The framework can be used to facilitate discussions to help countries improve and expand the breadth of protection provided by their NIP.

A review of factors influencing vaccination policies and programs for older adults globally

Policies and programs to increase vaccine coverage rates among adults 50 years of age or older are limited and vaccine uptake is often suboptimal. Our review evaluated evidence on the effectiveness and success of adult-targeted vaccination interventions and identified literature gaps. Literature was retrieved (2021) from PubMed, Embase, and Google Scholar databases. Outcomes assessed included data on an intervention's effectiveness and impact on vaccine uptake. Interventions were characterized thematically: affordability (n = 9), awareness (n = 25), and vaccination access (n = 6); and included influenza, pneumococcal, tetanus-containing, and herpes zoster vaccines. Interactive interventions directed toward patients, including provider-led educational initiatives and provider recommendations showed more positive associations than less interactive interventions, such as posters and reminder-recall letters. Provider interventions, including awareness campaigns, incentives, affordability efforts, or vaccination site expansion generally showed positive associations. Combining interventions was found to be successful across several studies. Barriers and interventions varied for population subgroups, therefore, tailoring programs is critical.

Closing the pneumococcal conjugate vaccine (PCV) introduction gap: an archetype analysis of last-mile countries

BACKGROUND

Pneumonia remains the leading infectious cause of global childhood deaths, despite the availability of pneumococcal conjugate vaccine (PCV) products and widespread evidence of their safety and efficacy.

OBJECTIVE

To map the landscape of countries that are yet to fully include PCV in their National Immunization Programs, we conducted an archetype analysis of country indicators related to barriers and facilitators for PCV decision-making.

METHODS

We created a country matrix focused on three key domains - health characteristics, immunisation factors, and policy framework, and identified ten related indicators. We scored countries based on indicator performance and subsequently ranked and grouped them into three archetypes of low-, moderate-, and high-barrier countries with regard to PCV introduction.

RESULTS

Our results indicated 39 countries (33 low- and middle-income countries [LMICs] and 6 high-income countries) that are yet to introduce PCV. Among LMICs, 15 countries were classified as 'low-barrier,' indicating factors favourable for PCV introduction such as high immunisation coverage of common childhood vaccines, supportive governments, and substantial disease burden and eligibility for Gavi support. Countries classified in the 'moderate-barrier' (12) and 'high-barrier' (6) archetypes demonstrated adequate capacity in immunisation systems but had competing national priorities and cost barriers that impeded policy decision-making on PCV introduction.

CONCLUSIONS

The current health and policy indicator-based categorisation provides an actionable framework to design tailored PCV advocacy within these last-mile countries. Policy approaches emerging from this framework can lead to strengthened decision-making on vaccine introduction and sustained vaccine access that can enhance child survival worldwide.

Healthy ageing: Herpes zoster infection and the role of zoster vaccination

Populations are ageing worldwide, with considerable time lived in ill-health, putting upwards pressure on healthcare budgets. Healthy ageing is defined as maintaining functional ability, including the ability to: meet basic needs; learn, grow and make decisions; be mobile; build and maintain relationships; and contribute to society. The risk and impact of infectious diseases increase with age due to immunosenescence. Vaccination can help to prevent disease in older adults, promoting healthy ageing and active lives. Herpes zoster (HZ) occurs when the varicella zoster virus is reactivated due to declining immunity. HZ is common, with a lifetime risk of one-third, and increases in incidence with age. HZ is associated with severe and intense pain, substantially affecting the functional status of patients as well as their overall health-related quality of life. HZ and its complications may result in prolonged morbidity, including persistent pain (post-herpetic neuralgia, PHN), hearing impairment, vision loss and increased risk of stroke and myocardial infarction. HZ and PHN are difficult to treat, substantiating the benefits of prevention. Vaccines to prevent HZ include a recombinant zoster vaccine (RZV). RZV has shown efficacy against the HZ burden of disease and HZ burden of interference on activities of daily living of over 90% in immunocompetent adults aged ≥50 years. Vaccine efficacy against HZ was maintained at over 70% at 10 years post-vaccination. Adult vaccination, including against HZ, has the potential to reduce burden of disease, thus helping to maintain functioning and quality of life to support healthy ageing in older adults.

Intention to Vaccinate against COVID-19 among Young Adults: The Role of Conspiratorial Thinking

The anti-scientific and anti-vaccine movements gained momentum amidst the health and socio-economic crisis brought about by the COVID-19 pandemic. These widespread pseudoscientific beliefs and the endorsement of conspiracy theories likely contributed to the COVID-19 vaccine hesitancy. The aim of this study was to explore which variables best differentiated between groups of vaccinated (n = 289), vaccine-hesitant (n = 106), and vaccine-refusing (n = 146) young adults. The study was conducted online at the beginning of the mass vaccination campaign in Croatia when the vaccine just became available for younger and non-vulnerable members of the general population. The demographic variables, COVID-19 anxiety, and conspiratorial thinking regarding COVID-19 were entered into the discriminant analysis. The function explaining 89.2% of the group differences, mostly between the vaccinated and vaccine-refusing, was largely defined by conspiratorial thinking regarding COVID-19 (0.852), followed by variables with substantially less discriminative power, including COVID-19 anxiety (0.423; lower in the vaccine-refusing group), political orientation (0.486; vaccine-refusing leaning less to the left), financial and educational status (0.435 and 0.304, respectively; both lower in the vaccine-refusing group), and religiosity (0.301; higher in the vaccine-refusing group). These results confirm that among young adults, the decision to vaccinate against COVID-19 might be heavily influenced by one's proclivity to engage in conspiratorial thinking.

Country score tool to assess readiness and guide evidence generation of immunization programs in aging adults in Europe

Objectives

Delaying of policies for immunization of aging adults, low vaccine uptake, and the lack of supportive evidence at the national level could diminish the value in health and economics of such programs. This study aims to develop a "country score tool" to assess readiness and to facilitate evidence generation for aging adult immunization programs in Europe, and examine the comprehensiveness, relevance, acceptability, and feasibility of the tool.

Methods

The tool was developed in two phases. First, a modified Delphi process was used to construct the tool. The process included a literature review, stakeholder consultations, and a three-round Delphi study. The Delphi panel included researchers, supra-national and national decision-makers of immunization programs recruited from five countries, using snowball sampling method. The consensus was predefined at the agreement rate of 70%. Pilot testing of the tool was conducted in the Netherlands, Germany, Serbia, and Hungary involving researchers in the field of health technology assessment. After assessing the countries' readiness, researchers evaluated four features, namely comprehensiveness, relevance, acceptability, and feasibility of the tool via an online survey that included 5-scale Likert questions. The percentages of affirmative answers including "agree" and "totally agree" choices were presented.

Results

The review identified 16 tools and frameworks that formed the first version of our tool with 14 items. Eight experts were involved in the Delphi panel. Through three Delphi rounds, four items were added, one was dropped, and all others were amended. The consensus was achieved on the tool with 17 items divided into decision-making and implementation parts. Each item has a guiding question, corresponding to explanations and rationales to inform assessment with readiness scores. Eight researchers completed the pilot testing. The tool was rated as comprehensive (75%), relevant (100%), acceptable (75%), and feasible (88%) by participants.

Conclusion

Through a thorough and transparent process, a country score tool was developed helping to identify strengths, weaknesses, and evidential requirements for decision-making and implementation of immunization programs of aging adults. The tool is relevant for different European contexts and shows good comprehensiveness, acceptability, and feasibility.

Vaccination coverage among older adults: a population-based study in India

Objective

To estimate the prevalence and explore the predictors of vaccine uptake among older adults in India.

Methods

We used data from the national Longitudinal Ageing Study in India, a national household survey conducted during 2017-2018. Based on interviewees' self-reports, we calculated population-weighted estimates of the uptake of influenza, pneumococcal, typhoid and hepatitis B vaccines among 64 714 Indian adults aged 45 years or older. We performed multivariable binary logistic regression analysis to examine the sociodemographic and health-related predictors of uptake of the vaccinations.

Findings

The coverage of each of the studied vaccinations was less than 2%. The estimated percentages of respondents reporting ever being vaccinated were 1.5% (95% confidence interval, CI: 1.4-1.6) for influenza, 0.6% (95% CI: 0.6-0.7) for pneumococcal disease, 1.9% (95% CI: 1.8-2.0) for typhoid and 1.9% (95% CI: 1.8-2.0) for hepatitis B. Vaccine uptake was higher among respondents with cardiovascular disease, diabetes or lung disease than those without any of these conditions. Uptake of influenza vaccine was higher among those with lung disease, while hepatitis B vaccine uptake was higher among those with cardiovascular disease or diabetes. Male sex, urban residence, wealthier household, more years of schooling, existing medical conditions and sedentary behaviours were significant predictors of vaccine uptake.

Conclusion

Targeted policies and programmes are needed for improving the low vaccination coverage among older adults in India, especially among those with chronic diseases. Further research could examine vaccine access, vaccine hesitancy, and vaccine-related information and communication channels to older adults and their health-care providers.

Challenges and Opportunities of Mass Vaccination Centers in COVID-19 Times: A Rapid Review of Literature

A mass vaccination center is a location, normally used for nonhealthcare activities, set up for high-volume and high-speed vaccinations during infectious disease emergencies. The high contagiousness and mortality of COVID-19 and the complete lack of population immunity posed an extraordinary threat for global health. The aim of our research was to collect and review previous experiences on mass vaccination centers. On 4 April 2021, we developed a rapid review searching four electronic databases: PubMed/Medline, Scopus, EMBASE, Google Scholar and medRxiv. From a total of 2312 papers, 15 of them were included in the current review. Among them, only one article described a COVID-19 vaccination center; all of the others referred to other vaccinations, in particular influenza. The majority were conducted in the United States, and were simulations or single-day experiences to practice a mass vaccination after bioterrorist attacks. Indeed, all of them were published after September 11 attacks. Regarding staff, timing and performance, the data were highly heterogenous. Several studies used as a model the Center for Disease Control and Prevention guidelines. Results highlighted the differences around the definition, layout and management of a mass vaccination center, but some aspects can be considered as a core aspect. In light of this, we suggested a potential definition. The current review answers to the urgency of organizing a mass vaccination center during the COVID-19 pandemic, highlighting the most important organizational aspects that should be considered in the planning.

Determinants of policy and uptake of national vaccine programs for pregnant women: results of mixed method study from Spain, Italy, and India

An important strategy for addressing maternal and newborn risks of disease is through vaccinating pregnant women. We conducted a mixed-methods study including a narrative literature review of drivers of maternal vaccination and key informant interviews in Spain, Italy, and India to characterize different approaches to national maternal immunization programs. Fifty-nine respondents participated in the study conducted between November 2018 and January 2019. Policies in Spain and Italy both reflect a life-course approach to vaccination, but recommendations and how they ensure uptake differs. Italy was focused on tracking of progress and mandates to ensure compliance in all regions, while Spain, an early adopter, relied more on advocacy and building provider acceptance. India includes Td in their national program, but the political will and advocacy for other vaccines are not seen. Needs for improving rates of maternal vaccination include education of health-care providers and pregnant women, use of central registries to track progress, stronger global guidance for use of vaccines, and engagement of champions, particularly obstetrician-gynecologists (ob-gyns). Health security concerns can also be leveraged to build political priority and needed platforms to detect disease and deliver vaccines in some countries. Understanding what drives a country’s maternal immunization program decisions and the success of implementation is useful in designing strategies to share best practices and guide support to strengthen platforms for maternal vaccination.

A global agenda for older adult immunization in the COVID-19 era: A roadmap for action

Given our global interconnectedness, the COVID-19 pandemic highlights the urgency of building a global system that can support both routine and pandemic/epidemic adult immunization. As such, a framework to recommend vaccines and build robust platforms to deliver them to protect the rapidly expanding demographic of older adults is needed. Adult immunization as a strategy has the broad potential to preserve and improve medical, social, and economic outcomes, including maintaining functional ability that benefits older adults, their families, communities, and countries. While we will soon have multiple vaccines against COVID-19, we must recognize that we already have a variety of vaccines against other pathogens that can keep adults healthier. They can prevent simultaneous co-infection with COVID-19, and may favorably impact- the outcome of a COVID-19 illness. Further, administering a vaccine against COVID-19 requires planning now to determine delivery strategies impacting how older adults will be immunized in a timely manner. A group of international experts with various backgrounds from health and aging disciplines met to discuss the evidence case for adult immunization and crucial knowledge gaps that must be filled in order to implement effective policies and programs for older adult immunization. This group, coming together as the International Council on Adult Immunization (ICAI), outlined a high-level roadmap to catalyze action, provide policy guidance, and envision a global adult immunization platform that can be adapted by countries to fit their local contexts. Further meetings centered around the value of adult immunization, particularly in the context of COVID-19. There was agreement that programs to deliver existing influenza, pneumococcal, herpes zoster vaccines, and future COVID-19 vaccines to over a billion older adults who are at substantially higher risk of death and disability due to vaccine-preventable diseases are more urgent than ever before. Here we present a proposed framework for delivering routine and pandemic vaccines. We call upon the global community and governments to prioritize action for integrating robust adult immunization programs into the public health agenda.