Nonstructural barriers to adult vaccination

ABSTRACT

Adult vaccination coverage remains low, despite vaccine recommendations, improved access, and reimbursement. Low vaccination coverage and an aging population at higher risk from vaccine-preventable diseases lead to preventable disability and deaths, straining healthcare systems. An Advisory Board meeting was, therefore, held to identify non-structural barriers to adult vaccination and discuss potential solutions to increase uptake. Many non-structural factors can influence vaccine uptake, such as heterogeneity in the population, (fear of) vaccine shortages, incentives, or mandates for vaccination, understanding of disease burden and personal risks, time and opportunity for healthcare providers (HCPs) to discuss and deliver vaccines during general practice or hospital visits, trust in the health system, and education. To address these barriers, push-pull mechanisms are required: to pull patients in for vaccination and to push HCP performance on vaccination delivery. For patients, the focus should be on lifelong prevention and quality of life benefits: personal conversations are needed to increase confidence and knowledge about vaccination, and credible communication is required to build trust in health services and normalize vaccination. For providers, quality measurements are required to prioritize vaccination and ensure opportunities to check vaccination status, discuss and deliver vaccines are not missed. Financial and quality-based incentives may help increase uptake.

Plain Language Summary

What is the context?

● As populations age, healthcare systems are increasingly struggling with the burden of adult disease. Multiple vaccines are already recommended for adults throughout their lifetime, and more are coming soon, however, even in countries with subsidized programs, few adults are fully vaccinated, leading to frequent cases of illness, disability, hospitalization, or death, which could have been prevented.

What is new?

● Experts from Europe and the US joined an Advisory Board meeting to find out what is stopping people from getting vaccinated, particularly when vaccines are free, and how this can be helped in future.

● The decision to get vaccinated can vary for different subgroups of the population, and can be influenced by vaccine shortages, rules about vaccination, and understanding the disease severity and need for vaccination. In addition, doctors may not have enough time and opportunity to discuss and provide vaccines during visits or may not feel comfortable raising the issue of vaccination with their patients.

● To overcome these issues, both patients and doctors must change. Patients need: greater awareness of how illness impacts overall health and quality of life; better conversations with their doctors to address vaccination concerns; and trustworthy information from health services. For providers, vaccination prioritization should be linked to quality measurements, with collaboration from trusted community members to reinforce the importance of prevention, thus ensuring opportunities are not missed to discuss prevention and vaccinate. Normalizing adult vaccination is important for this.

What is the impact?

● Taking a patient centered prevention approach will help protect adults and ease the burden of vaccine-preventable disease.

KEYWORDS:

• Adult
• vaccination
• barriers
• drivers
• trust

Introduction

Adult vaccination coverage fails to reach recommended target levels in virtually every country, resulting in preventable disease cases, disability and deaths.^1,2 For example, in 2019 in the United States (US), only 21.8% of adults received age-appropriate vaccinations (i.e., Td, Tdap, and influenza routinely recommended for all adults; herpes zoster and pneumococcal vaccines with age-based recommendations).³ Coverage was 27.6% in adults aged under 50 years, and 8.2% in those aged 50–64 years, with lowest rates among Black (15.9%) and Hispanic (17.3%) adults versus White (23.7%) and Asian (23.5%) adults.³ Within the European Union, adult vaccination programs vary considerably, with 8 to 17 publicly funded programs offered in different countries.⁴ Concerns around low adult vaccination coverage rates are compounded by the aging of the global population, as older adults are at greater risk from vaccine-preventable diseases (VPD).

Improving adult vaccination has become a priority to protect the vulnerable and reduce the burden of VPDs on healthcare systems – these key vaccination benefits were highlighted by the COVID-19 pandemic.⁴ Multiple studies have investigated why coverage is so low in adults compared with children, and some clear issues have been identified, such as a lack of recommendations, infrastructure for delivery, and reimbursement issues.^2,5 However, even in countries where these barriers have been addressed, adult vaccination coverage remains low, for reasons that remain poorly described, and there are many possible explanations as to why. The goal of this Advisory Board, with experts from Europe and the US, was therefore to attempt to identify these non-structural barriers, so that they may be resolved in future.

Experts who had published on adult vaccination and/or adult care, including infectious disease specialists or vaccinologists, were selected, to gain perspectives from healthcare professionals familiar with the patient and treatment setting, but who were not yet themselves full-time vaccinators. The primary question discussed was ‘What barriers exist to adult vaccination where recommendations are already in place?’ This was further broken down to discuss barriers for adult patients, physicians, and new vaccinators (e.g., pharmacists and midwives). The goal was not to focus on structural barriers (i.e., financial, access, and recommendation issues) which have been the topic of many analyzes, but to gain insight into day-to-day practical issues, education, and awareness, and to broaden our understanding of why coverage is so often low, even in settings which appear to have few procedural barriers to adult vaccination.

Defining the problem

Despite improved COVID-19 vaccination access in countries such as the US and increasing vaccination rates in Latinx and African American populations,⁶ insufficient coverage rates remain an issue among adults. For example, in many countries, racial and ethnic minority groups still have higher hospitalization and lower vaccination rates for vaccine-preventable disease than the broader population.⁷

Many varied factors influence vaccine uptake, such as heterogeneity in the population, or access to the healthcare system. Demand can also be driven by perceptions of availability and need. As demonstrated during the COVID-19 pandemic and in years with a shortage of influenza vaccine, uptake increases when people believe there is not enough vaccine⁸ or there is an obligation to be vaccinated.^9,10

A primary reason for COVID-19 vaccine refusal, especially among younger adults, appears to be a gap in understanding of disease burden and severity and of the importance of vaccination.¹¹ Self-identification of symptoms rarely occurs, so even older age groups who are at increased risk often do not access health systems in a timely fashion and, therefore, do not receive recommended vaccines. For older adults, there may also be other access issues to consider, for example, homebound and disabled people may have transport difficulties and rely on home visits to receive healthcare and vaccines.¹² These factors can result in lower vaccine uptake, despite a will to be vaccinated, and can differ between countries and from person to person.

These obstacles to accessing care inevitably lead to a second barrier to increasing vaccine uptake in adults – specifically, the limited opportunities for general practitioners (GPs) to discuss and offer vaccines, due to the short duration of consultations (around 10 minutes in most cases). Patients typically see their GP for a health issue requiring immediate attention, and in this context, it is difficult to raise the importance of adult vaccination to the level of other health issues. For example, for most members of the public, there is very limited overlap between GP visits and (influenza) vaccinations.

In recent years, the use of alternative vaccinators has been expanded, in an attempt to improve access to vaccination and prior to the pandemic, 20 countries allowed vaccines to be delivered in pharmacies, and 13 countries allowed pharmacists to administer them.¹³ Recently, following the COVID-19 pandemic, France also extended the administration of adult and childhood vaccines to pharmacists.¹⁴ In the current environment, however, there are still many missed opportunities to vaccinate; for example, when people come in for their COVID-19 vaccines, there is often no mention of co-administering other recommended vaccines during that visit, such as influenza vaccination. Likewise, divergent and often confusing rules on what vaccines may – or may not – be administered by an alternative vaccinator, further complicates any discussion of vaccination and adds complexity to supply chains. Even for patients with regular healthcare provider (HCP) contact, vaccination opportunities are often not utilized: for example, in a French cohort at risk of invasive pneumococcal disease, all of whom had regular GP, specialist and hospital visits, only 8% and 26% were vaccinated against pneumococcal infection and influenza, respectively.¹⁵ Similarly, a recent study found that limited awareness among healthcare professionals of the benefits of influenza vaccination in preventing myocardial infarction was a factor limiting vaccine uptake in at-risk patients in the cardiology department.¹⁶

Defining solutions

The current situation strongly suggests that relying only on HCPs to take the initiative yields insufficient uptake rates. A two-pronged approach, targeting both patients and HCPs, is required, using push-pull mechanisms i.e., to pull patients in to request vaccination, and to push HCP performance on initiating the vaccination discussion and ultimately, providing vaccination. Patient, provider and quality working groups can be established.

For patients, three themes emerged. First, the discussion around vaccines and disease must be broadened: instead of focusing on vaccinating against a specific disease, an overall prevention and care perspective, including impact on quality of life, should be adopted. An intergenerational approach to healthcare is also important i.e., understanding the benefits of vaccination throughout the life-course. This will require reframing the conversation about patient responsibility for their own health, throughout their life. A systematic review on drivers of adult vaccination found that an attitude of self-efficacy i.e., a person’s belief that they can influence their own health (e.g., through previous vaccinations, health screenings, preventive behaviors) had a positive influence on vaccine uptake in older adults.¹⁷

Second, there is a need to engage patients in more in depth and interpersonal conversations, for instance using motivational interview techniques. This may help to increase confidence in vaccination and to avoid potential ‘entrenchment syndrome’ whereby some people may move from a neutral to an anti-vaccine position, if they feel they are being forced into a course of action.

Third, providing credible communication increases trust in authorities and helps to increase vaccination uptake. A recent review of the literature on attitudes to influenza vaccination among adults worldwide found that providing educational materials was important, and trust in healthcare services was the most important promoter of influenza vaccination.¹⁸ In Europe, the European Centre for Disease Prevention and Control provides practical guidelines for HCPs to address vaccine hesitancy and build trust in vaccination.¹⁹ Easy, clear messaging is, therefore, crucial to engage patients. The systematic review on drivers of adult vaccination confirmed that patient and HCP education and VPD awareness are positive drivers of routine adult vaccination.¹⁷

For providers, studies have shown that a range of interventions can help HCPs improve (pneumococcal) vaccine uptake in older adults, for example, inpatient vaccination protocols, preventative health checklists, built-in electronic reminders and decision-making tools, and education.²⁰ However, in practice, quality measurements may be required to improve HCPs performance on vaccination.

Adult vaccination needs to be normalized, so that it is automatically considered by HCPs and patients as a required part of adult care, just as vaccination is seen as a standard part of pediatric care. Currently, there are discrepancies between physician and patient reporting of vaccination discussions and actual administration of vaccines, as can be seen from coding data. Access to a centralized registry of vaccinated patients would be useful to redress this issue, and provide HCPs with an opportunity to check the patient’s vaccination history and offer missed vaccines. In the absence of a central registry, a portable electronic health record could provide the same, or even better, benefits.

Financial considerations and quality ratings can play a part in increasing vaccine uptake. Pharmacists may be more effective at vaccinating and offering other recommended vaccines to patients during a visit, because they have a direct financial incentive. In the UK, high coverage rates for influenza are linked to reimbursement, although rates are different in pediatric and adult programs, which may affect uptake and normalization of vaccination. The acceptability of financial incentives varies by country and may be considered in some societies, such as the UK or US, while vaccine uptake in other countries may be more responsive to quality-based incentives.

Conclusion

There are a variety of general and personal factors that influence older adult vaccination, and understanding the non-structural barriers in a community are essential to increasing uptake. The relationship between the person to be vaccinated and the HCP is very important, as it is at this level that vaccination takes place. For this relationship to develop, the HCP must have the opportunity to carry out prevention in the best possible conditions. There are no easy solutions to increasing vaccine confidence amongst older adults, but training of health providers, including pharmacists and community-based providers, as well as trusted messengers and providing incentives for quality education is a good start. Good interpersonal communication skills are needed. A patient-centric approach should be employed, recognizing that the needs of older adults extend beyond a desire to prevent a vaccine preventable disease, but may be based in a desire to protect others, continuing to contribute to society, have a good quality of life or avoid catastrophic expenses. For the person to be vaccinated, increasing confidence includes gaining knowledge of the risks, the expected benefits of vaccination and any side-effects. The role of the health authorities is to put in place clear recommendations with clear objectives. Increased tracking of results is needed, to measure whether vaccination moves toward normalization as a part of a broader preventive approach. This can only be a dynamic and evolving process.

Author contributions

Authors were involved in advisory board. All authors substantially contributed to the interpretation of the relevant literature and the development of the manuscript. All authors gave final approval before submission.

Acknowledgments

The authors thank L.J. Tan for participation of advisory board. Business & Decision Life Sciences Medical Communication Service Center for editorial assistance and manuscript coordination, on behalf of GSK. Kavi Littlewood (independent medical writer) provided medical writing support, on behalf of GSK.

Disclosure statement

MD is employed by GSK and hold shares in it. JG received fees from Sanofi, Pfizer, MSD, GSK for participation of advisory boards. LPD received fees from GSK for consulting and writing assistance. FE received lecture fees and travel expenses from Sanofi. The authors declare no other financial and non-financial relationships and activities.

Data availability statement

No dataset was generated or analyzed for this publication.

Additional information

Funding

GlaxoSmithKline Biologicals SA was the funding source and took in charge all costs associated with the development and publication of this manuscript.