Background
Europe is aging; it is estimated that by 2060, 28.4 % of the population of the 27 Member States of the European Union will be 65 years or older, compared to 18.6 % in 2014 [
1]. As a result of immunosenescence (the gradual deterioration of the immune system), co-morbidity, and general frailty, this population is susceptible to infectious diseases [
2], resulting in higher mortality and morbidity rates than in young adults [
3]. Infections may lead to irreversible frailty and thereby further dependency on long-term healthcare [
4]. At the same time, community-dwelling older adults will be more socially engaged, which increases the chance of transmission of infectious diseases towards this population [
5]. Apart from possible benefits to individuals in this age group, vaccination may yield social benefits such as lower overall costs of healthcare, as demonstrated by childhood vaccinations [
6].
Several European countries offer elderly vaccination against influenza and in some instances against pneumococcal disease, tetanus, and diphtheria. In the Netherlands, for example, influenza vaccination is offered to everyone of 60 years or older and pneumococcal vaccine to groups at risk. However, proposals have been made to expand the Dutch immunization program for persons aged 60 years and older to include pneumococcal disease, herpes zoster, and pertussis [
7].
For an immunization program to be successful and produce the most health benefits, its acceptance is crucial. It is therefore necessary to understand why the different reasons given by older persons accept or reject vaccination. So far, no qualitative study has explored these arguments for persons aged 50 years and older in the Netherlands. The aim of this study is to explore the motives to accept or refuse vaccination among community-dwelling persons aged 50 years and older in the Netherlands.
Discussion
We identified eight themes that influence the decision of persons aged 50 years and older to accept vaccination. These are healthy aging, usefulness of vaccination in older age, risk of getting an infectious disease, vaccine characteristics, severity of the disease, experiences of previous vaccinations, influence of healthcare workers and other people, and need for information.
Vulnerability to infectious diseases as experienced by the participants and the usefulness of vaccination in older age seem to be the most important factors influencing the decision to accept a vaccine. Concerning vulnerability, the participants fall into two distinct groups. The first did not feel vulnerable to infectious diseases, often due to their healthy lifestyle. The second did feel vulnerable because they suffer from chronic disease, have themselves already experienced disease previously, or someone near to them had. This is an important finding because the core argument for offering vaccination to older people is their biological susceptibility to infection [
2].
With regard to the usefulness of vaccination in older age, it were mostly the older participants who expressed doubts. Questions were raised about vaccines that could prolong life. Life is seen as finite; it should not be prolonged at all costs, especially when death could bring deliverance from suffering. In addition, the participants felt that aging should occur normally without any interventions. They saw more need for vaccination at a younger age, though this would depend on one’s health status at the time of vaccination.
The usefulness of vaccination in older age is scarcely treated in the literature [
10]. We feel that this theme came to light because of our explorative design and the fact that the study concerns not only the current offerings but also adding more vaccines to the program. Participants were asked to give all reasons they might have for accepting vaccinations (not only influenza immunization) instead of asking about specific ones. This might have given the participants a cue to take a broader perspective, allowing umbrella arguments to come to mind.
Furthermore, as part of the theme of severity of the disease and its implications, the motive of wanting to protect others emerged in the focus groups as a reason to accept vaccination. This is another topic that has not been addressed in other studies. It is briefly touched upon in Kwong
et al. [
11]. There, the participants believed the vaccine would protect themselves and their family around them, especially the grandchildren. Also in our study, the participants expressed a need for vaccination in order to babysit for their grandchildren and to comply with the wishes of their children, as well as to protect their ill spouses. It is not clear why this topic was pronounced in our study but less so in others. It might reflect the increasing attention given to vaccinating adults in the Netherlands in recent years, after the Health Council released a report on moving toward a vaccination program for all ages [
12]. This may have raised awareness of immunization among general practitioners, which in turn could have led to offering more vaccinations or giving more information on the availability of vaccines. The motive of protecting others could be useful when considering vaccination against whooping cough (pertussis), which was regarded as a terrible childhood disease. The participants were often willing to accept pertussis vaccine in order to protect their grandchildren from it.
Overall, in contrast to our findings, (dis)trust in medicine and medical personnel and in the health services in general is often mentioned in the literature, notably in the studies of Telford and Rogers, Harris and Evans [
13‐
15]. Also, in contrast to others who found that logistic problems and/or financial barriers could impede the acceptance of vaccination [
16], our study did not identify any logistic problems. This divergence might be related to the fact that in the Netherlands the influenza vaccine is provided by the general practitioner. Logistics are therefore not much of an issue because 75 % of the population have access to their GP within less than a kilometer [
17]. Furthermore, influenza vaccine is given free of charge, which could explain why cost is irrelevant to the participants in our study.
The findings of our qualitative study still need to be explored quantitatively. Nonetheless, our results suggest that targeted messages or personalized vaccination could be the key to a high vaccination uptake when offering older adults other vaccines alongside the existing influenza vaccination program. Information should be objective and independent. Information providers should also take into account that younger and older people may have different attitudes on some of the factors that were identified and illustrated in this study. Given that some older adults seem not to prefer prolonging life but would rather pursue quality of life, they might be more motivated to accept herpes zoster vaccination than pneumococcal vaccination. Although others might have the opposite inclination toward these vaccines, our findings indicate that the focus should not be solely on prolonging life.
Second, the participants did not feel vulnerable in general. Every person has a risk of infection at some time in life. However, older adults have an extra risk factor, namely their age. In order to give older adults the opportunity to fully profit from available vaccinations, this risk information could be shared. The ideal person to provide such information would be their GP. He or she has records of disease history and other information on patients in their clinics that would give them the background for a more precisely targeted advice. Moreover, the GP is by definition an important person in the decision-making process of older adults, as shown by our study especially for the elderly.
However, the younger participants preferred to rely on the internet for guidance in their decision on whether to accept vaccination. Special attention is therefore needed to ensure that appropriate information is easy accessible on the internet. Nevertheless, it still has to be recognized that some participants did not consider vaccination useful in older age.
Whereas most studies consider vaccination programs in their current composition, we looked into adding vaccines to existing influenza programs. Examples of potential additions are herpes zoster vaccine, pertussis vaccine, and most notably pneumococcal vaccine. A particular strength of this study is its broad explorative design. No pre-specified models were used to guide the topics that would be raised in the focus groups. This allowed the participants to speak freely about vaccination. That might explain why some themes that had not been covered before came up in the sessions, such as usefulness of vaccination in older age.
There are also a few limitations to this study. Unfortunately, we did not gather demographics on the participants except for their age and residential setting. Had we done so, we would have been able to distinguish between the individual participants and their views on vaccination.
Furthermore, the persons who participated in the focus groups were probably already interested in research, which could imply a selection bias. In addition, the gender distribution was not balanced, with 65 women and 15 men, so the attitudes of men are underexposed.
We tried to recruit a representative sample by inviting persons aged 50 years and older from different residential settings across the Netherlands. Unfortunately, we were only able to recruit two persons living in a care home. We approached several care homes, but the administrators usually refused to cooperate because the residents were not deemed able to participate.
Ideally we would like to have selected the participants randomly. However, this was not feasible because of the focus-group setting. The participants may have had to make arrangements for long travel and we would have needed enough individuals to form the focus groups. Three of the 13 focus groups had less than the minimum of five participants, but the shortfall was due to illnesses on the day they were convened. It is unfortunate that with this recruitment method it is not known how many persons were invited to take part, but we feel this was the most feasible approach.
Last, seven of the 13 focus groups were convened at a time when the media carried frequent reports on the role the pharmaceutical industry allegedly played in the provision of vaccines. This publicity could have influenced the results of our study because, as mentioned earlier, the participants would gather some of their information from the media. Still, mistrust was not found to be a key theme in this study, so the media influence may be considered low.
Competing interests
The authors declare that they have no competing interests. The study was funded by the Dutch Ministry of Health, Welfare and Sport.
Authors’ contributions
RE conducted all the focus groups and analyzed the data. RE, PK, and HM all participated in the study design and the structuring of the different themes reported in the manuscript and the writing of the manuscript. All authors read and approved the final manuscript.