VITAL at a glance

WP1: the burden of infectious diseases (and their consequences)

Background

The increasing ageing population in the European Union (EU) is leading to a significant demand for healthcare services, particularly concerning infectious diseases among older adults, including those over the age of 50.
As people age, they experience immuno-senescence, which is a natural decline in the immune system's function. This process increases their risk of severe infections and complicates diagnosis, especially in elderly care settings.
Vaccination remains a vital strategy to help reduce the incidence of infectious diseases and promote healthy ageing. To make sure we develop and improve vaccines for older adults, we need a deeper understanding of the major infectious diseases affecting this demographic.

Objectives

The overall objective of WP1 is to enhance the understanding of the epidemiology, risk factors and burden of disease of existing vaccine-preventable (VP) infectious diseases in adults above the age of 50 across Europe.

Some Key Messages/ Findings from Range of Research Studies

Although infectious diseases do not result in higher hospitalization rates compared to other conditions, they significantly affect quality of life, frailty, and daily function. As age increases, so does the burden of these diseases, with mortality rates for those over 80 estimated to be 3-15 times higher than for those aged 50 and above.
Premature death due to infectious diseases in aging adults (50+yo) is a major concern, with Year of Life Lost (YLL) accounting for 68-87% of the total Disability-Adjusted Life Years (DALYs).
Understanding the effects of immunosenescence (age-related immune decline) and vaccine effectiveness is crucial. However, observational studies encounter challenges due to confounding factors, especially in areas with low vaccination rates and limited age-sex-specific demographic and health data. These challenges complicate efforts to accurately evaluate vaccine impact in older populations.
Creating a comprehensive EU-wide database on the infectious disease burden in older adults is challenging due to significant differences across European countries. Variations in demographics, health status, comorbidities, access to healthcare, and epidemiological patterns make it difficult to generalize data across regions.

These findings underscore the urgent need for better data collection, preventive measures, and strategies to address the growing burden of infectious diseases in older adults. Continued research and collaboration across Europe are essential to safeguard this vulnerable population.

Links to Key Publications to Date

WP2. the waning of the immune responsiveness associated with age and other intervening factors

Improving immunity to infections through vaccination in older adults

Background

Vaccination plays a vital role in combating the morbidity and mortality associated with infectious diseases.
Current vaccination programs do not sufficiently protect older adults, leaving them vulnerable to severe illnesses.
Ageing impacts immune responses to vaccination, the exact extend of this impact, variation between individuals and vaccines and how we can predict this remains elusive.

Main objective

Execute a clinical vaccine study to understand the mechanisms underlying vaccine response in different age groups against three different vaccines.

Key findings (I):

A booster vaccination for influenza induced comparable antibody titers in all age groups, whereas lower antibody concentrations were observed in older adults following primary pneumococcal and COVID-19 vaccination as compared to young adults.
A shorter persistence of these antibody responses towards the 6 months timepoint was observed in older adults for all vaccines.
Similarly, in another cohort, we showed that middle-aged adults who have not been previously primed (either through natural exposure or vaccination) exhibited weaker long-term immunity after MenACWY vaccination compared to previously primed adolescents.

Conclusions (I):

Early priming is important in maintaining long-term immunity.
Although the quantity of vaccine-induced antibodies within an individual in the VITAL cohort appears to be vaccine-type specific, a small group of mostly older male adults exhibited low responses to multiple vaccines, suggesting that this group should be the focus of improved vaccination strategies.

Key findings (II):

For the first time, we have evidence that immune cell subsets can be utilized to stratify individuals based on their response to multiple vaccines.
We have identified immune cell subset clusters, which we called immunotypes, that categorize individuals more effectively than age.
Furthermore, when these immunotypes were evaluated in relation to the antibody response to both influenza vaccination as well as multiple vaccines, we identified both good and bad responder immunotypes.
Finally, based on the measurements of immune cell subsets, we have developed a new metric that identifies immune disruption, which could potentially serve as a groundbreaking diagnostic tool for future risk assessment and monitoring.

Conclusion (II):

These findings will enhance our ability to predict who may have a lower response to vaccines and identify pathways that could be targeted for future novel intervention strategies. Current data suggest specific cell types that may be involved in these responses.

Key findings (III):

The project also provides a deeper understanding of frailty and inflammageing (chronic low level inflammation frequently observed in older adults) which could help identify individuals at higher risk of infections, necessitating alternative vaccination strategies.
several of these inflammatory markers are linked to our identified poor responder immunotypes.

Conclusion (III):

A comprehensive analysis that correlates all immune ageing parameters with various vaccine-specific immune responses (including antibody levels, T cell responses, cellular kinetics, and gene expression profiles) will provide a holistic view of factors affecting vaccine response and its key determinants. This information will be crucial in guiding vaccine development and new vaccination strategies for older adults.

Perspective:

The enhanced understanding of immunosenescence that the project has obtained could be pivotal in improving current and future vaccination programs, especially with the advent of new vaccines. It will also aid in the future selection of new adjuvants and in identifying individuals who would benefit from current vaccine strategies to mitigate the issue of immunosenescence.

Links to Key Publications to Date:

WP3. the value of vaccination in older adults

The Value of Vaccines

Background

Vaccination plays a vital role in combating the morbidity and mortality associated with infectious diseases.
Current vaccination programs do not sufficiently protect older adults, leaving them vulnerable to severe illnesses.
This gap in protection results in significant medical expenses and a greater societal burden due to infectious diseases in our rapidly aging populations and therefore more effective vaccination strategies for older adults are urgently needed.

Objectives

WP3 aims to investigate the full economic impact of current ID management and new preventive interventions.
This includes developing economic models to measure and report these impacts convincingly to decision-makers; the economic models consider factors such as frailty level, type of infection, healthcare exposure, place of living and health condition.
These efforts are crucial for improving public health strategies and ensuring effective ID management in ageing populations across Europe.

Some Key Messages/ Findings from Range of Research Studies

Vaccination plays a fundamental role in ensuring healthy aging and preserving quality of life for older adults and efforts should focus on increasing vaccination rates to maximize its benefits.
Maintaining current vaccine coverage rates among older adults is projected to lead to notable increases in for example, influenza, pertussis, HZ, and pneumococcal disease burden over the next several decades due to population aging.
Switching from standard-dose vaccines to higher-dose vaccines not only reduces pressure on hospital capacity but also leads to significant cost savings.
Higher frailty prevalence is strongly associated with lower GDP per capita, especially in the 65–79 age group.
Heterogeneity in contact behaviour is important within the population(s) by age and health conditions as well as the interplay between participants frailty conditions and their contact behaviour.
Current and innovative modelling approaches help to identify strengths, weaknesses, and evidential requirements for decision-making and implementation of immunization programs of ageing adults as well as demonstrating capabilities in for example, quantifying the fiscal impact of infectious disease outbreaks to inform decision-making.

Links to Key Publications to Date

WP4. the education/training of key stakeholders on vaccination of older adults

Background

Vaccination plays a vital role in combating the morbidity and mortality associated with infectious diseases.
WP4 investigated the determinants and the information needs concerning informed decision making regarding older adult vaccination.

Main objectives

We explored the perspectives and needs of older adults regarding vaccination and vaccines
Moreover, we investigated the perceptions, attitudes and knowledge gaps of healthcare professionals involved with vaccination of older adults.
Finally, we developed a framework containing comprehensive and innovative educational resources regarding vaccines for healthcare professionals engaged in adult and elderly care.

Key findings and conclusions (I)

We conducted focus groups to explore the perceptions and decision-making behavior of older adults regarding vaccinations in Italy, France, Hungary and the Netherlands.
Influenza and tetanus vaccines were commonly known among participating older adults. The awareness of vaccines against pneumococcal disease and herpes zoster were lower.
Participants expressed a need for more information on possible side effects, contra-indications and duration of protection of vaccines.
Information is a condition for decision-making on vaccination. General practitioners were found to be the most important sources of information on vaccines.

Key findings and conclusions (II)

We conducted a systematic review to identify effective educational interventions that could enhance healthcare professionals’ ability to engage in a dialogue with older adults on vaccination.
Tailored reminders and multicomponent interventions effectively assist healthcare professionals in addressing vaccines with older adults.
Education-only interventions appear to be less effective compared to other interventions regarding vaccination uptake, attitude, and knowledge.

Key findings and conclusions (III)

We developed an educational framework containing comprehensive and innovative resources regarding vaccines and immunization strategies for healthcare professionals engaged in adult and elderly
The framework for educational interventions summarizes all the key findings of WP4 during the VITAL project and displays newly created materials (videos, infographics), links to relevant and reliable data sources on vaccines and vaccine preventable diseases as well as overviews of available courses and training resources.
The portal hosting the framework is available online, free of charge and is accessible for healthcare professionals in five European languages.