Assessment of Vaccine Literacy in People Affected by Multiple Sclerosis: A Cross-Sectional Study From Italy Free

Vaccine literacy (VL) refers to obtaining, understanding, and effectively using vaccine-related information to make informed health care decisions.¹  This includes evaluating information sources, understanding vaccine risks and benefits, and accessing health care services to receive vaccines.^2-4  High levels of VL encourage proactive health behaviors essential for enhancing individual and public health outcomes. Notably, VL directly affects vaccination rates within communities.^5,6  For individuals with chronic diseases such as multiple sclerosis (MS), VL plays a critical role due to their increased vulnerability to infections.⁷  However, despite widespread immunization programs, vaccine hesitancy remains a significant barrier among the general population⁸  and those with chronic illnesses.⁹  Vaccine hesitancy is characterized by a delay in vaccination or a refusal to receive a vaccination despite available services.¹⁰  The World Health Organization identifies vaccine hesitancy as a top global health threat, highlighting the importance of addressing VL to combat this issue.^11,12 

Low VL is linked to reduced adherence to preventive measures, including vaccination, due to the complexity of medical information as well as the decision-making processes.¹  Technological advancements and expanded access to information have increased the need for reliable medical guidance, especially among individuals with chronic diseases.¹³  In MS, undervaccination is often due to misinformation, concerns about vaccine interactions with treatments, and false contraindications.¹³  As MS disease-modifying therapies (DMTs) suppress immune responses, people with MS are at increased risk of infections, making vaccination crucial despite any potential concerns.^14,15  Despite the well-documented benefits of vaccination, hesitancy remains a significant issue among people with MS: Findings from studies indicate that 10% to 20% of them are hesitant to receive a vaccination, often due to knowledge gaps and insufficient promotion by health care workers.⁵  In Italy, these rates are even higher, with influenza vaccination hesitancy reaching 41.8%.¹⁵  This reluctance poses a challenge, as vaccination is particularly crucial for people with MS who may face heightened risks from infections. However, initiatives aimed at promoting vaccination in this population have had limited success.¹⁶  The lack of impact underscores the need for more effective strategies, which could include tailored education campaigns and improved communication between health care providers and patients. One promising avenue involves assessing VL levels among people with MS.

Understanding VL, especially in the most vulnerable groups, can provide valuable insights into the barriers faced and inform the development of targeted interventions to address these obstacles.¹⁷  By identifying and addressing specific gaps in knowledge and perceptions, health care systems can implement more effective strategies to encourage vaccination among people with MS. Nurses, who are often in close contact with people with MS, are uniquely positioned to assess and enhance VL, playing a critical role in supporting informed decision-making.¹⁸  Despite this potential, the extent to which VL has been specifically assessed and addressed in the MS population remains largely unexplored. Current evidence reveals a significant gap in understanding how vaccination-related knowledge, attitudes, and perceptions influence decision-making among people with MS. Although findings from studies have highlighted high levels of vaccine hesitancy in this group,^5,15  little is known about the specific informational needs or misconceptions that contribute to this reluctance. For instance, concerns about vaccine safety, particularly regarding potential interactions with DMTs, may play a role, but data in this area are scarce. Similarly, the influence of health care providers, including nurses, on vaccination behavior has not been thoroughly investigated in the context of people with MS.

Addressing these knowledge gaps is essential, as people with MS often require tailored educational approaches that account for their unique medical conditions and psychological needs. Nurses, given their trusted and frequent interactions with patients, are well suited to assess VL levels and identify barriers to vaccination. By doing so, they can implement targeted interventions to dispel misconceptions, empower patients with accurate information, and ultimately support informed decision-making. No studies have specifically evaluated VL in people with MS, highlighting an urgent need for research to guide effective vaccination promotion strategies. Understanding VL levels in this population could significantly improve vaccination coverage and reduce infection rates, particularly among those undergoing immunosuppressive therapies.¹⁹  The development of interventions based on VL assessments could play a pivotal role in overcoming vaccine hesitancy, improving health outcomes, and enhancing the overall care of people with MS. The goal of this study was to assess the VL level in people with MS and examine its correlation with key sociodemographic and clinical variables.

A cross-sectional monocenter study was conducted between April 2023 and September 2023 at MS Center, University of Bari, Bari, Italy. We used the STrengthering the Reporting of OBservational Studies in Epidemiology guidelines.²⁰  The sample size calculation was based on the data analyses performed (Mann-Whitney U and Kruskal-Wallis tests) and, with a P value of .05 and a power of 0.80, it was expected to be at least 132 participants.

Patients were recruited based on a purposive sampling strategy, ensuring that all participants met the following inclusion criteria: diagnosis of MS, optimal cognitive abilities, and patient consent to the treatment of their personal data for participation in the experimental study. Exclusion criteria were lack of confirmed MS diagnosis or presence of other demyelinating diseases; severe psychiatric disorders, cognitive impairment, or comorbidities that would interfere with the study; recent experimental vaccination treatments or changes in DMTs in the past 3 to 6 months; pregnancy, breastfeeding, or substance abuse; and an inability to provide informed consent or comply with study requirements. For the data collection, a research nurse administered a structured questionnaire to patients during their routine visits at the Bari MS center. All the participant responses were entered directly into a computer platform with a specific form for data entry. The clinical and demographic data relevant to our study were extracted from the Italian Multiple Sclerosis Register (IMSR).²¹ 

This study was conducted following the ethical principles of the Declaration of Helsinki and used clinical data from patients extracted from the IMSR (https://registroitalianosm.it). It received approval from the ethical committee of the Azienda Ospedaliera Universitaria Policlinico di Bari (Study REGISTRO SM001). Written informed consent was obtained from all participants prior to their inclusion in the study in accordance with ethical guidelines and institutional requirements.

All variables were collected from the IMSR database, including sociodemographic (sex, age, education) and clinical data (patient comorbidities, MS phenotype, age of onset, disease duration, ongoing DMTs, and Expanded Disability Status Scale [EDSS] scores). A multiple-choice questionnaire of 5 sections with 10 questions each was used to collect data about vaccine determinants. Derived from the European Health Literacy Survey Consortium, it asked about respondents’ (1) vaccination behavior over the past 5 years, (2) vaccine beliefs, (3) trust in vaccines, and (4) perceived risks of vaccination. The last component of the questionnaire was the HLS19-Vaccination (HLS19-VAC), a 4-question test to assess VL in the general population. The Italian version of HLS19-VAC was validated in an Italian study and in 11 other countries on large cohorts of patients using different data collection methods.²²  The test evaluates 4 aspects of the management of vaccine information, with an item for each point regarding immunization information: access/obtain, comprehend, evaluate/judge, and apply/utilize. Respondents choose from a 4-point Likert scale of very easy (4) to very difficult (1). The HLS19-VAC score is calculated as a percentage of items answered as very easy or easy and can thus be 0, 25, 50, 75, or 100. High scores correlate with high VL.^22,23  At the beginning of the questionnaire, 2 items designed to investigate patient satisfaction with nursing care were included.

Clinical and demographic characteristics were calculated as mean (SD) for continuous variables and as frequencies (proportions) for categorical. The association of some variables (sex, education, age, EDSS, and VL score) was evaluated by Kruskal-Wallis test, Mann-Whitney U test, and Spearman ρ. Analysis was performed using IBM SPSS, with a statistical significance level set at a P value of .05.

A total of 157 people diagnosed with MS were enrolled in the study and completed the questionnaire. Of these, 90.4% had relapsing-remitting MS, 86.4% were women, mean age was 34.77 (± 9.55) years, 54.1% were aged 30 to 49 years, and 40.1% held a bachelor's degree. Most patients were employed (73.9%) and received their diagnosis between the ages of 10 and 29 years (65.6%). The median EDSS score was 2 (IQR, 2-3). The most prescribed DMTs were dimethyl fumarate (23.6%) and natalizumab (17.2%). Additionally, 93% of participants reported being satisfied with nursing care and 82.8% felt comfortable discussing vaccination with their MS nurses (TABLE 1).

Regarding vaccination behavior, 99% of participants or their family members had received vaccinations within the past 5 years. Opinions on vaccine beliefs were mixed: A total of 36% disagreed with the notion that vaccines weaken the immune system, whereas 33% agreed. Similarly, 43% rejected the idea that vaccines cause the diseases they aim to prevent whereas 27% agreed and 30% were undecided. A significant majority (83.5%) agreed or strongly agreed that vaccinations were important to protect themselves and their families, whereas 75.8% believed vaccines were safe and 80.3% found them effective. Furthermore, 75.8% considered vaccination compatible with their religious beliefs and 86.6% believed it plays a crucial role in preventing the spread of serious diseases. Finally, 63.1% of respondents perceived a high or very high risk of developing a disease if unvaccinated (TABLE 2).

The median (IQR) score of VL was 75 (range, 50-100). The majority of respondents (70.0%) found it easy or very easy to locate vaccination information for themselves and their families. More than half of the participants (55.4%) found it easy or very easy to understand why they and their families need to be vaccinated. A significant portion (67.5%) considered it easy or very easy to understand which vaccinations their families require. An equal proportion (70.0%) found it easy or very easy to decide whether to receive the influenza vaccine (Table 2).

The Mann-Whitney U test was used to compare the VL scores between male and female participants. The results indicated no significant difference in VL scores between the 2 groups: The mean rank for women (n = 134) was 79.04, and it was 78.74 for men (n = 23). The Mann-Whitney U value was 1.535, with a Wilcoxon W of 1.811 and a z value of –0.031. The P value was .975. The Kruskal-Wallis test was used to assess differences in VL scores among 3 age groups: 18 to 29 years (n = 56), 30 to 49 years (n = 85), and 50 to 70 years (n = 16). The mean ranks for these groups were 72.75, 79.47, and 98.38, respectively. The results indicated no statistically significant differences between the age groups (H = 4.252; df = 2; P = .119). The relationship between education level and VL scores shows that the mean ranks across different education levels were middle school at 53.35, high school at 74.03, bachelor's degree at 89.01, and postgraduate at 80.63. The test results indicated a significant difference between the groups (H = 8.550; df = 3; P = .036; FIGURE). Spearman ρ correlation analysis between the VL score and EDSS score shows a correlation coefficient of 0.049, indicating a weak and nonsignificant correlation (P = .543).

This study provides a comprehensive overview of VL, beliefs, and behaviors among people with MS, offering valuable insights into their attitudes toward vaccination and the factors influencing their decision-making processes.

The results of the HLS19-VAC questionnaire highlight a generally positive attitude toward vaccine behavior among the participants. The majority reported that they or a family member had been vaccinated in the past 5 years, indicating a high level of adherence to vaccination recommendations.²⁴  This suggests a good baseline acceptance of vaccines, which can be attributed to the significant information and awareness campaigns conducted in response to the COVID-19 pandemic. However, beliefs about vaccines shows a more complex scenario. A substantial proportion of patients in the study have misconceptions regarding the safety and effectiveness of vaccines. A notable percentage of participants believe that vaccines can weaken the immune system, cause the diseases they are meant to protect against, or produce severe adverse effects. These misconceptions can undermine vaccine confidence and may be a barrier to achieving higher vaccination rates in people with MS. Burian and colleagues²⁵  highlighted that concerns about vaccines are widespread among people with MS and necessitate targeted education, especially for those with more severe psychopathological symptoms (anxiety or depression) and those who are generally skeptical of vaccination. Public health campaigns and health care providers (eg, MS nurses) should focus on spreading accurate information about the safety and efficacy of vaccines to address these concerns.²⁶  In contrast, the vaccine trust score was high, indicating that despite some misconceptions, there is strong overall trust in the importance, safety, and effectiveness of vaccines. This trust is crucial for maintaining high vaccination coverage and suggests that efforts to improve VL are likely to have a positive impact.

Among respondents, the perceived risk of contracting infectious diseases for people with MS who were not vaccinated is high, which aligns with the high trust in vaccines. This perception is an important motivator for vaccination, as individuals who recognize the risks of not vaccinating are more likely to seek out vaccines for themselves and their families. This ease of access and comprehension is critical for informed decision-making and suggests that current communication strategies are effective. However, there is still room for improvement, particularly in making information even more accessible and understandable to address any remaining confusion. Vaccination literacy had a problematic overall score among the sample, despite results revealing that participants generally find it easy to access and understand information about vaccinations. However, there is more difficulty in understanding the underlying reasons for vaccination. This suggests that although logistical aspects are clear, there is a need for better education on the importance of vaccinations.

The relationships between VL and the sociodemographic and clinical variables provide relevant insights. There is no significant difference in VL scores between male and female participants. This suggests that gender does not significantly influence VL in this sample, which is consistent with findings from other studies showing that VL remains generally stable across genders in many populations.²¹  No significant differences in VL scores were observed between the 3 age groups (18-29, 30-49, and 50-70 years), although the oldest age group (50-70 years) showed a slightly higher mean rank. This finding suggests that age, in this study population, is not a critical factor influencing VL, which is somewhat unexpected, as findings from previous studies have often indicated lower VL among older populations.²¹  The lack of statistical significance might reflect the high level of regular health care interactions across age groups, which could mitigate age-related differences in VL. Our study population consists primarily of patients who have regular contact with health care providers due to the high percentage of participants receiving intravenous medication. This regular contact allows them to benefit from educational interventions provided by MS nurses, which are fundamental in building the nurse-patient trust relationship.²⁷  Findings from other studies suggest that lower VL is common among younger people with MS, particularly those without regular contact with health care professionals.²⁸ 

In contrast, educational level was found to have a significant effect on VL scores. Participants with a bachelor's degree had the highest mean ranks, followed by those with postgraduate education, and those with a middle school education had the lowest ranks. This outcome is consistent with existing literature, which consistently highlights the impact of educational attainment on health literacy, including VL.^23,27  Previous evidence shows that individuals with lower education tend to have lower health literacy skills compared with those with higher education.²⁹  Individuals with higher education levels are likely to have better tools for accessing, understanding, and applying health-related information, including information about vaccination.

Tasks that other patients may find relatively simple, such as scheduling vaccinations or understanding vaccine recommendations, can be challenging for people with MS and lower VL to manage,³⁰  so improving VL for this population is essential to enhance their understanding and trust in vaccinations and to reduce the influence of potentially dangerous misinformation. This underscores the need for targeted educational interventions, such as those by MS nurses, to address specific informational needs and concerns.^21,31  The lack of a significant correlation between VL and EDSS score suggests that physical disability did not have a meaningful impact on VL for our study participants. This finding implies that cognitive or educational interventions aimed at improving VL can be effectively applied across different levels of disability without the need for significant adaptation.

This study offers valuable insights into VL and attitudes among people with MS. Educational level plays a crucial role in shaping VL, as higher levels of education are often associated with a better understanding of health information. Therefore, tailoring educational interventions to individuals with lower educational backgrounds is essential to improving VL and vaccine confidence. Regular visits to MS centers can significantly enhance VL. These visits provide patients with frequent opportunities to engage with health care professionals, particularly nurses, who play a key role in educating them and addressing any concerns about vaccinations. This ongoing interaction helps reinforce patients’ understanding of and trust in vaccines.

Our sample size is relatively small, and the study is monocentric, which may limit the generalizability of the findings. In addition, the reliance on self-reported data could introduce bias and the cross-sectional design prevents the assessment of changes over time. Future research should focus on the inclusion of a larger and more diverse population as well as adopt longitudinal approaches to gain a better understanding of VL trends. Finally, the phrasing of the vaccination behavior questions (“Have any of your family members, including you and your children, undergone a vaccination in the past 5 years?” and “Have you, your children, or someone in your family had any vaccinations in the last 5 years?” [Table 2]) could introduce ambiguity, as respondents might answer “yes” even if only their children were vaccinated. This may have contributed to the high reported adherence level despite mixed beliefs about vaccines. Additionally, the questionnaire did not specify the type of vaccine, which could have influenced responses due to varying levels of trust in specific vaccines.

Improving VL is crucial for people with MS to make informed health decisions. Although our study findings highlight a high level of trust in vaccines, they also reveal significant gaps in VL, contributing to misconceptions and vaccine hesitancy. Lower educational attainment, in particular, is associated with inadequate vaccine knowledge and, consequently, lower VL. This at-risk population should be the target of tailored educational interventions, ideally provided by specialized MS nurses, to promote greater vaccine acceptance and improve VL. Future studies should further explore the impact of specific educational strategies on improving VL in people with MS, particularly among those with lower educational levels. Research could also investigate the long-term effects of regular health care interactions, such as those with MS nurses, on sustaining improved VL.

The authors thank Dr Agnese Renna for data collection.