A psychological insight of Moroccan adults’ immunisation behaviour towards emergency vaccines

Sample size

The selected sample was calculated online through a free and open software program called: ‘Open Source Statistiques Épidémiologiques pour la Santé Publique’.¹⁵ For an error risk: α = 5%, an expected proportion of positive perception: p = 82%,¹⁶ and a population size: N = 77 886 students, the minimum number of students to be included is 227.

A non-probability sampling procedure called snowball was used. In fact, the data were collected through students and teachers contacts, by circulating the survey questionnaire to people matching the required characteristics. They were then asked to suggest other people with a similar profile.

Questionnaire

We designed a questionnaire, composed of 10 parts. The first section is a description of the survey and its objectives. The questionnaire itself begins in the second part. It includes demographic data (gender, age, city of residence, education level, etc.), information related to SARS-CoV2 vaccination, including vaccination profile and perception of vaccines recommended by public health authorities. We have also collected information regarding COVID-19 disease. The remaining part of the questionnaire focuses on the measurement of some vaccine anxiety disorders (anxiety, perceived stress and post-traumatic stress disorders [PTSD]) and insomnia, by using four questionnaires mentioned further in the text:

• First scale: The severity of anxious symptoms was scored according to the Hamilton scale.¹⁷ This ladder measures the seriousness of anxiety symptoms on 14 parameters such as anxious humour, fears, insomnia, depressed humour, etc.
• Second scale: Perceived stress level was evaluated using the Perceived Stress Scale (PSS).¹⁸ The 10-item PSS questionnaire provides a very popular and widely used tool to understand how different situations affect feelings and perceived stress.
• Third scale: PTSD was assessed using the post-traumatic stress disorder Checklist Scale (PCLS).¹⁹ This scale is simple and easy to complete. It is very useful for screening for PTSD in clinical and research settings. The scale consists of 17 items, rating the level of each component of the 17 associated symptoms.
• Fourth scale: The Insomnia Severity Index (ISI) scale was used to evaluate insomnia.²⁰ This short seven-item scale, allows the assessment of insomnia by determining satisfaction of sleep, daily performance, and thus anxiety regarding sleep difficulties.

Volunteers were asked to test the questionnaire in order to estimate how long it would take them to complete it, and thus to modify any incomprehensible question. Our pre-test evaluation of the questionnaire, allowed us to estimate a duration of approximately 15 min for each student. Therefore, we decided to conduct the interviews during their break.

Statistical analysis

The quantitative variables were presented as a mean and its standard deviation, whereas the categorical ones were described as a percentage.

The unpaired samples T test was applied to compare quantitative variables. The Chi-square (χ²) test or Fisher’s exact test were used to compare qualitative variables. A p-value inferior than 0.05 was deemed significant for this survey. Variables exhibiting a significance threshold of p ≤ 0.05 were included in the backward stepwise logistic regression model. The IBM SPSS Statistics software, Version 21.0, supported all statistical analyses.

Participants’ characteristics according to stress level related to vaccination

The impact of sample characteristics on the level of stress regarding vaccination is reported in Table 5.

Although women were less exposed to stress when compared to men, yet the difference between the two groups was not significant (p = 0.33). The stressed students tended to be older (mean age ± standard deviation in years: 23.78 ± 6.41 vs. 21.86 ± 3.77, p = 0.003), from establishments other than medical faculty (p = 0.01), and who lived alone as tenants (p = 0.001).

On the other hand, and according to participants’ vaccination profile, the respondents who received their third dose of the SARS-CoV-2 vaccine presented a significantly higher level of perceived stress than those who did not receive this dose or who were interested in receiving it (p = 0.02).

Protecting others (p = 0.02) and vaccine accessibility (p = 0.001) were the less significant reasons associated with stress regarding vaccination. However, no significant difference was found concerning refusal or hesitation reasons about COVID-19 vaccination.

In terms of perception, students with a negative experience with the first two doses expressed a more remarkable level of stress, than those with a positive perception. Nevertheless, this difference was insufficiently significant (p = 0.09).

We note that participants with a high level of confidence in social networks as an informational source regarding immunisation displayed higher stress compared to those with less faith (p = 0.01). Meanwhile, students who believed in scientific journals were found to be less stressed (p = 0.01).

The impact of sociodemographic characteristics of the respondents on the level of stress regarding vaccination

Results analysis of potential stress-related factors regarding vaccination indicated that stressed responders tended to be older. A study conducted by Rogowska et al.²¹ revealed that vaccinated students were older and exhibited high levels of stress and fear related to COVID-19 compared to the unvaccinated group. We note that, in the present work, the percentage of stressed students in the vaccinated group was higher than that among the unvaccinated ones, although the difference was statistically not significant. Therefore, further research is needed to elucidate this relationship. This would suggest that older students may pay more attention to their own safety when dealing with new vaccines. It is possible that older students may have different educational or risk perception levels, and thus are more conscious during emergency situations.²²

The relationship between gender and immunisation behaviour has been reported in several previous studies.^23,24,25,26 Gender-related behaviours may influence variations in vaccine acceptance and perception within the adult population.²⁶ A study assessing associations between mental health and intent to be vaccinated against COVID-19 revealed that women were found to be more anxious than men.²³ Yet another survey showed more negative attitudes towards such vaccines among men.²⁷ In terms of physiology, it appears that women are more likely to present side effects than men after immunisation.^28,29 Accordingly, they report being more concerned about vaccine safety and efficiency than men, which may contribute to a lower vaccination rate among women.³⁰ In our study, we found that female students developed less stress regarding SARS-CoV-2 vaccines compared with male participants. This finding may be explained by the frequent use of preventive care services by women to the detriment of men.³¹

The results highlighted a significant difference between stress level presented by medical students compared to students from other institutions (p = 0.01). The evidence suggests that medical students appear to be considerably less apprehensive about vaccination. These findings are coherent with previous studies.^32,33,34 One explanation for this might be the nature of their background, where a more clinical approach is required. Therefore, medical students would have the opportunity to acquire greater insight, and have a greater sense of responsibility for themselves and for others.

We evaluated the impact of housing on the level of stress towards vaccination. As a result, our findings indicate that students who lived alone in a rental presented a significant increased level of stress compared to the others. It seems that students staying alone in a rental are experiencing a deeper sense of loneliness than those living with others. Previous investigations highlighted the association between the lack of social connection, depression and social anxiety, as well as reduced vaccine use.^35,36 Consequently, this connection between social link and psychological well-being ought to be considered to improve the adherence of this group within the next vaccination programmes, while preserving their mental health.

The impact of reasons for accepting vaccination on the level of stress regarding vaccination

Protecting others and vaccine accessibility were reasons for acceptance, significantly less associated with stress (p = 0.02, p = 0.001). A previous study conducted among Chinese university students revealed the reasons behind their vaccination behaviours.² Most of their respondents who accepted vaccination indicated that perceived benefits of vaccination for themselves prompted them to do so, followed by their perceptions of decreased contamination risks for others. This suggests that university students are more conscious when faced with emergency situations, expressing a high level of social responsibility, and therefore positively influence the vaccine perception and acceptance.

Since the inoculation campaigns began, Morocco has been actively working to facilitate the access to vaccination services by establishing local centres and providing free vaccine to the entire population. On the other hand, and as a young population, university students benefited from the opportunity to get vaccinated in a period where many types of vaccines were already available. Thus, they were able to decide when, where and what type of vaccine they would receive. Hence, it is possible that the accessibility and availability of such vaccines might provide a double benefit in terms of university students’ vaccination behaviour, allowing them to express particular, rather positive, emotions while accepting this action.

The impact of vaccination profile and COVID-19 vaccination perception on the level of stress regarding vaccination

A further outcome relevant to our study is the booster dose. Indeed, the percentage of stressed people in the group that received the third dose was significantly higher (p = 0.02). These results are at odds with another publication, whereby respondents who were willing to receive such a dose expressed better mental health.⁷ Previous studies have indicated that post-vaccination side effects, inability to tolerate the first two doses’ adverse reactions, and negative perception of the booster dose’s benefits were among the most cited reasons for refusing the third dose.^37,38,39 Apparently, although some students accepted the booster dose for different reasons, their attitude towards this so-called dose might not necessarily be positive. Accordingly, further investigations are required to highlight and understand the relationship between the mental health status and the booster dose.

We note that side effects were somewhat more susceptible to be present within the stressed group as compared to those who exhibited low, or no, stress regarding vaccination. In fact, stress-related responses following vaccination are not considered as new insights.¹³ Indeed, vaccination refers to the process of vaccine administration, namely the pain involved in the shot, the presence of needles and or blood, the waiting line, and others’ reactions in the post-vaccination waiting room.^13,40 All these events can cause psychological distress.⁴⁰ In addition, these immunisation stress-related responses are more susceptible when new vaccines first appear, and may promote vaccine hesitancy.^13,14,40 Therefore, further investigations are required to identify individuals at highest risk for developing stress-related adverse events and thus attempt to uncover potential predictors.

No significant relationship between stress and vaccination perception was observed in our study. Yet, previous studies have noted the presence of an eventual association between these two variables. Students with high stress levels, and who reported more severe depressive symptoms, were more susceptible to have a negative perception of the SARS-CoV-2 vaccines.⁴¹ Further studies indicated that individuals with poor mental health had decreased intentions to adopt health-related behaviours.^42,43 It seems that stress can prompt negative cognitive responses, such as negative behavioural ones.⁴¹ The non-significance of our results could be attributed to the period when the survey was performed. Indeed, prior studies have demonstrated that vaccine intent changes over time.^44,45

The impact of participants’ confidence in informational sources on the level of stress regarding vaccination

One other interesting finding revealed from the analysis of the current survey was the confidence in the informational sources regarding COVID-19 vaccination. As it turns out, participants with a high level of trust in social networks were more susceptible to present vaccination stress. Nevertheless, students with a high level of confidence in scientific journals were significantly less exposed to stress. As a matter of fact, mass media communication has a major role in shaping attitudes towards vaccines.²⁷ Prior investigations have stated the existence of an important nexus between social networks, vaccine resistance, and the related conspiracy assumptions.^46,47 Loomba et al.⁴⁸ quantified the effect of misinformation on vaccination coverage, wherein, compared to real facts, misinformation drove down intent to immunise. This research group demonstrated that science-based misinformation is powerfully associated with a low rate of SARS-CoV-2 vaccine adoption.⁴⁸ In this way, public health organisations could communicate data on vaccination via the official media, referring to scientific studies, thereby increasing the perception of vaccines and reducing their psychological impact on the population.²⁷ Besides, healthcare professionals may also contribute to this process, so-called decision support. For example, in a study of pregnant women in New Zealand, decision support was effective in reducing anxiety about immunising their children and raising their intention to undergo vaccination.¹¹

Influencing factors related to COVID-19 vaccination stress

The final logistic regression model suggested that age, institution, housing and confidence level in informational sources concerning SARS-CoV-2 vaccines were the only variables that were significantly associated with stress towards vaccination. We suggest that this could be because of possible interactions amongst explanatory variables, which might eclipse the real relationship between stress as an explained value and predictor variables.

The authors extend their heartfelt appreciation to Rim Benkaddour for her invaluable assistance in refining the English language used in this article. All the people who have actively contributed to this work have been cited. They also thank all the Moroccan students who answered the questionnaire, and express their deep gratitude to all the resident doctors in the laboratory of Epidemiology, Clinical Research and Public Health. This work is supported by CNRST Morocco under an excellence research grant.