The corresponding author Dr Sitong Luo is an Associate Professor of Behavioural and Implementation Sciences at the Vanke School of Public Health, Tsinghua University and a member of the World Health Organisation Technical Advisory Group on Behavioural Sciences for Better Health. The first authors, Ms Siwen Huang and Dr Mengyue Zhang, are a PhD student and Postdoctoral Fellow at Tsinghua University respectively.
Vaccination is one of the most effective and cost-effective public health interventions we have. Yet around the world, many older adults still miss out on recommended vaccines such as influenza, pneumococcal and shingles vaccines despite the availability of services.
Why?
The answer isn't as simple as "they don't want the vaccine."
Vaccine hesitancy is much more than outright refusal. It reflects a complex mix of thoughts, emotions, social influences and perceived practical barriers that shape vaccination decisions. Understanding those factors—and how we can address them—was the motivation behind our new systematic review.
We brought together evidence from studies around the world to understand what drives vaccine hesitancy among older adults and which interventions have been used to tackle it. In total, we included 72 studies following the PRISMA guideline. Most were published in developed countries, with a surge since the COVID-19 pandemic, reflecting the growing attention to adult vaccination.
So what did we find?
We identified a wide range of factors influencing vaccine hesitancy from 49 studies, which could be grouped into three broad levels (Figure 1):
- Individual factors, such as personal beliefs, previous experiences and sociodemographic characteristics.
- Group and social factors, including interpersonal influences, community norms and information environment.
- Practical factors, such as willingness to pay and perceived convenience of access.
These findings reinforce an important message: vaccine hesitancy isn't driven by a single reason, but a complex of multilayered determinants.
Figure 1: The framework of determinants of vaccine hesitancy toward routine immunisations recommended for older adults
We also reviewed 23 intervention studies and grouped existing approaches into five categories (Figure 2): dialogue-based interventions, reminder and recall systems, incentives, passive information provision and multi-component interventions. We identified a lack of theory-based, contextually grounded, multi-component interventions which may have stronger potentials to reduce vaccine hesitancy.
Figure 2: Intervention strategies to mitigate vaccine hesitancy among older adults
Another finding stood out
Many studies used the term vaccine hesitancy inconsistently, often mixing up people's motivation with whether they actually got vaccinated. But these aren't always the same thing. Someone may fully intend to be vaccinated but struggle with cost, transport or appointment convenience. Others may have easy access but remain unconvinced. Distinguishing hesitancy from objective practical barriers is important because they call for different solutions.
So where do we go from here?
Rather than asking, "How do we persuade older adults to get vaccinated?", perhaps we should ask, "What support does this person actually need?"
For some, a trusted recommendation from a healthcare professional may make all the difference. Others may benefit from clear conversations about vaccine safety, while some simply need an appointment reminder or easier access to vaccination services. There is unlikely to be a one-size-fits-all solution.
As populations continue to age, improving vaccination among older adults is becoming increasingly important—not only for reducing the burden of infectious diseases every year, but also for future pandemics. We hope our review helps move the conversation beyond simply measuring vaccine uptake toward understanding why people hesitate, and how we can design smarter, more targeted interventions that support healthy ageing.
Read the full article in Age and Ageing - Determinants and mitigation strategies of vaccine hesitancy toward routine immunisations recommended for older adults: a systematic review
