The Social Attitudes Towards the Booster Dose of the COVID-19 Vaccine and the Associated Factors Among Residents of Riyadh, Saudi Arabia

Background As a result of the Coronavirus (COVID-19) pandemic, global health was significantly affected. Therefore, the booster dose was approved to be administered to people who had completed a primary vaccination series in order to enhance their immunity. This study aims to identify the factors that lead to willingness or hesitancy toward the third/booster dose of the COVID-19 vaccine, to estimate the rate of acceptance and hesitancy toward the third/booster dose of the COVID-19 vaccine, and to measure third/booster dose COVID-19 vaccine literacy among residents of Riyadh. Methods This study is a quantitative analytical cross-sectional, questionnaire-based study from March 2022 to December 2022. The data were gathered using a convenience sampling technique from 435 participants in the Riyadh region 16 years old and above by using a validated questionnaire. Results Among the participants, 72.6% were females; 53.4% of young participants aged 16-25 years had a good knowledge of the booster dose versus 26.2% of those aged 45 years or above, with reported statistical significance (P=0.001). The functional literacy of the COVID-19 vaccine which is defined as the ability to read and write effectively was higher among the non-hesitant group compared to the hesitant group. The interactive/critical literacy of the COVID-19 vaccine, which is defined as the advanced abilities that enable people to make sense of information so they may take decisions that are relevant to their own lives, was higher among the non-hesitant group compared to the hesitant group. 72.2% of the study participants reported that if the booster dose of the COVID-19 vaccine was not mandatory by the government, they would not have taken it. Also, 19.1% thought that taking the booster dose of the COVID-19 vaccine would endanger their lives. Conclusion The findings of the current study revealed that the factors leading to the willingness or hesitancy toward the booster dose of the COVID-19 vaccine include age, gender, and side effects. Also, measuring the COVID-19 vaccine literacy revealed that it is higher among the non-hesitant group than the hesitant group although it was statistically insignificant. Meanwhile, further studies should be done to track and measure COVID-19 vaccine literacy over time, and examine the factors associated with the booster dose of COVID-19 vaccine hesitancy for more validation and application.


Introduction
The coronavirus (COVID-19) pandemic had a significant impact on global health [1].It spreads quickly, infecting thousands of people worldwide and has been associated with widespread morbidity and mortality [2,3].As of April 14, 2022, a total of 500,186,525 cases and 6,190,349 deaths of COVID-19 had been confirmed [4].The COVID-19 vaccination has been gaining interest globally since the pandemic began in 2020 as a means of prevention [5].The effectiveness of the first vaccine against the COVID-19 disease was proven for the first time on the date of December 11, 2020, by the Food and Drug Authority [6].Since then, vaccination programs were rolled out globally.Initially, the vaccine was available only to 16-year-olds and above.After less than a year on May 10, 2021, the vaccine became available and safe for the age group of 12-15 years old [6].With time, the immunity and clinical protection of the vaccine has fallen below a rate deemed sufficient in the vaccinated population [5].
Therefore, the administration of booster dose to those who had completed a primary vaccination series was approved in an effort to enhance the immunity against the viral disease [5].Since December 19, 2021, efforts started by the Saudi Ministry of Health (MOH) urging the population to take a booster dose of COVID-19 [7].The objective of a booster dose is to restore vaccine effectiveness from initial doses as well as to help people maintain strong protection against the antigen from severe coronavirus disease [8].As a result, the booster dose of the COVID-19 vaccine has been shown to reduce the transmission and spread of the coronavirus [9].Vaccine hesitancy is defined by the World Health Organization (WHO) as "the delay in acceptance or refusal of vaccination despite availability", and has resulted in a global health threat with negative socioeconomic and health effects on individuals and their communities [10].Despite the evidence of the effectiveness of the booster dose in enhancing immunity against the two variants Delta and Omicron, the receiving of the booster dose is still controversial [10].The acceptance rates of the booster dose of COVID-19 varied based on several factors including age, occupation, gender, vaccination history, educational level, vaccine literacy, monthly household income, health status and governmental laws [10][11][12][13].Females are at higher risk of being infected with COVID-19 [14].Meanwhile, a study found that the mortality rate is higher for males, but respondents are not considered to be a complete representation of the attitudes of residents in other regions of Italy, as the survey was conducted in a single center [14].
This study focused on estimating the acceptance and hesitancy in a different geographical place and population which is Riyadh, the capital of Saudi Arabia, as well as investigating whether the preference of people to take the dose stems from complete confidence and conviction, or because of the government's laws that require the booster dose to enjoy personal interests such as traveling, working, and shopping.Therefore, it intended to assess societal vaccine literacy, as well as the factors that lead to the willingness or hesitancy toward the booster dose of COVID-19, to increase society's awareness of the booster dose of COVID-19 for future booster dose acceptance.This study attempted to close these gaps in the literature.So, this study could be able to contribute to the understanding of acceptability and hesitancy about taking the COVID-19 booster dosage.Hence, it could help to design strategies to overcome hesitancy and improve COVID-19 vaccine takeup.

Study design, setting and participants
A quantitative, cross-sectional analytical, questionnaire-based study was conducted in the Riyadh region from March 2022 to December 2022.The data for this study were collected between 22 August and 25 August 2022 using an online questionnaire to explore the social behavior toward the booster dose of the COVID-19 vaccine and the associated factors among residents of Riyadh, Saudi Arabia.This study targets subjects aged 16 or above who live in the Riyadh region.

Data collection
Data was collected from Riyadh residents who were 16 years old and above using a developed self-reported online questionnaire through Google Forms and added 12 items for COVID-19 vaccine literacy which was developed by Biasio et al. [15].The questionnaire comprises 40 questions overlying the following five sections.The first section for sociodemographic information (six items) included age, gender, occupation/employment status, educational level, income, and chronic diseases.The second section for COVID-19 vaccine history (four items) included the vaccine type, and the number of doses.The third section for booster dose of COVID-19 vaccine hesitancy (seven items) and the fourth section for booster dose of COVID-19 knowledge (11 items) were both assessed on a five-point Likert scale: "Strongly Disagree = 1", "Disagree = 2", "Neutral = 3", "Agree = 4", "Strongly Agree = 5".A scale that devolved by Biasio et al. was used for the fifth section to measure COVID-19 vaccine literacy which has already been validated (12 items) four items for the functional literacy which is defined as the ability to read and write effectively, and eight for the interactive/critical literacy which is defined as the advanced abilities that enable people to make sense of information so they may take decisions that are relevant to their own lives, assessed on a four-point Likert scale: "Never = 1", "Rarely = 2", "Sometime = 3" to "Often = 4" [15,16].A pilot study has been performed to pre-test the study.

Sampling and sample size
A minimum target sample size of 435 was calculated using the single proportion equation (n = z α ^ 2 p (1-p) / d ^ 2), where p=0.62 which is the proportion of prevalence of the willingness to take the booster dose in recent research [11], d=5%, and Z for 95%=1.96; the result was 362.03.To account for a potential nonresponse rate of 20%, 20% of the sample size was added, resulting in a total sample size of 435.

Statistical analysis
Statistical analysis was conducted using IBM SPSS version 21 (IBM Corp., Armonk, NY, USA); 5% was set as the significance level.Overall knowledge level regarding COVID-19 booster dose was assessed by summing up discrete scores for different correct knowledge items.The overall knowledge score was categorized as poor level if the participant's score was less than 60% of the overall score and good level of knowledge was considered if the participant's score was 60% or more of the overall score.Descriptive analysis was carried out using frequency distribution and percentages for study variables such as respondents' personal information, income level, and vaccination data.COVID-19 vaccine literacy among COVID-19 vaccinehesitant and COVID-19 vaccine non-hesitant groups was compared using an independent-sample t-test.Pearson chi-square test for significance was used to perform cross-tabulation to show the distribution of participants' overall knowledge level by their socio-demographic data.Also, participants' willingness or hesitancy toward the booster dose of the COVID-19 vaccine was tabulated.

TABLE 3: Factors affecting participants' knowledge regarding third/booster dose of the COVID-19 vaccine
A total of 72.2% of the study participants reported that if the booster dose of the COVID-19 vaccine was not mandatory by the government, they would not have taken it.Also, 54.9% thought that the first two doses of the COVID-19 vaccine protected them and there is no need for a booster dose, 48.7% believed there is a high probability that more side effects of the booster dose of the COVID-19 vaccine would be discovered which made them hesitant about taking it, and 42.5% reported that they cannot tolerate another dose of the COVID-19 vaccine because the side effects of the previous (first and second) doses were severe but only 19.1% thought that taking the booster dose of the COVID-19 vaccine would endanger their lives.On the other hand, 56.3% reported that they took the booster dose of the COVID-19 vaccine to protect their family from getting the COVID-19 infection (Table 4).[17].In this study, the majority of the respondents were females which could be linked to psychological gender differences.Previous studies also have shown that women have better compliance with public health policies during the COVID-19 pandemic as they are more likely to define it as a serious health problem [18].
A validated instrument has been used to determine the COVID-19 vaccine functional and interactive/critical literacy of the study participants [15].Functional literacy is the ability to read and write effectively, whereas interactive/critical literacy refers to the advanced abilities that enable people to make sense of information so they may take decisions that are relevant to their own lives [16].In this study, participants who accepted the booster dose scored higher on functional, interactive/critical literacy than those who were hesitant to get a booster dose.The association between vaccine literacy and vaccine hesitancy was measured using similar tools in one study and it was statistically significant that the functional literacy among vaccine non-hesitant group was higher than among the vaccine-hesitant group with a mean difference of −0.49, however, it was statistically insignificant in the current study [11].
This study looked at the socio-demographic factors and their association with the knowledge about the booster dose of COVID-19.There was a dominance of females at 74.6% of participants.However, males were found to have higher knowledge about the booster dose for COVID-19 at 49.6%, p=0.009.This was not found in a study conducted in the UAE where age and gender variables were insignificant.However, it was found that post-graduate educational status has higher knowledge about the booster dose at 72.6%, p <0.001, and employees in the health sector also have a higher knowledge at 54.9% p = 0.03 [19].
This study found age differences in knowledge about the booster of the COVID-19 vaccine favoring younger ages (16-25) at 53.4%, p=0.001.This was not demonstrated in studies done in Jordan, the United States, and China [11,12,17].A possible explanation of this result can be due to the difference in the level of familiarity with the new media compared to traditional media among different age groups.Social media outlets were more effective in delivering messages about COVID-19 and preventive measures that include vaccination.Chronic diseases were not significantly associated with increased knowledge about booster doses.Meanwhile, in a study conducted in Ajman University, it was a crucial factor that encouraged people to take the booster dose [19].It was noticed only a UAE study discussed the association between socio-demographic data and the knowledge level of the booster dose of COVID-19, and the results showed an association between the socio-demographic data and the knowledge of the booster dose [19].This study showed that participants with a higher education level, with a prior history of COVID-19 infection, and a previous experience of taking the vaccine all have demonstrated more knowledge of the booster dose.
Result differences between the studies could be due to the geographical, sample size, and sample characteristics variability, which indicates the need for more studies to be done for more validity.
Participants in a study done in Jordan claimed that the severity of the side effects and a mild infection with COVID-19 were additional reasons that probably kept them from getting a booster dosage of the COVID-19 vaccine [17].In this study, 48.7% of participants thought there is a potential for more side effects from the booster dose of the COVID-19 vaccine which has made them unwilling to take it.Because of this, strategies are needed to be focused and consider the reasons that make people hesitant to receive the booster dose.These findings suggest that the main reported reason for not receiving a booster vaccine dose was the lack of solid scientific evidence about the advantage of the booster dose, followed by the perceived lack of benefit from a booster dose in the short term and the fear of potential side effects.
Regarding the protective motivation that drives people to get the vaccine, there is a study conducted in Fukushima that reported 81% believe that the main reasons for accepting the booster vaccination is related to infection control necessity, while 47.3% believe that vaccines are highly effective [20].Also, a study found that China had the highest acceptance rate at 88.6%, and that nations with acceptance rates over 80% often had high levels of trust in their governments [21].Furthermore, additional recent research claimed that the majority of those who did not obtain a booster dose showed less satisfaction with their initial COVID-19 vaccinations and that they lost trust in the Saudi Ministry of Health, the WHO, medical professionals, and the efficacy of all vaccines [21].On the other hand, this study discovered that taking the booster dose increased significantly with government laws.However, prior studies have established a lack of knowledge regarding the influence of government laws on social behavior, especially in Saudi Arabia.

Limitations
The study's methodology relied on convenience sampling and an online questionnaire that participants completed themselves.Meanwhile, online surveys can provide a private environment for the respondents to finish the questionnaires honestly and accurately, thereby reducing any possible social desirability or interviewer biases.However, the access to the online survey that was used in this study was limited by the people who had access to the internet, and by those who were interested in this study.Although a comprehensive survey has been conducted, there remains a possibility of non-response bias, which may impact the reliability and generalizability of our findings.It was noticed that females were more acceptable and responsive to answer the questionnaire; so this study was limited by unequal distribution where females were dominant in the sample.Also, a history of side effects from previous doses and media preferences were important confounding factors that could not be eliminated.

Research implication
This study contributes to the understanding of acceptability and hesitancy about COVID-19 booster dosage.Hence, it can assist the Saudi Arabia government and relevant agencies to design more scientific and targeted roll-out strategies to overcome hesitancy and improve the booster dose of the COVID-19 vaccine uptake.

Conclusions
In conclusion, the findings of the current study revealed that the factors leading to the willingness or hesitancy toward the booster dose of the COVID-19 vaccine include age, gender, and side effects.Also, measuring the COVID-19 vaccine literacy revealed that it is higher among the non-hesitant group than the hesitant group although it was statistically insignificant.Meanwhile, further studies should be done to track and measure COVID-19 vaccine literacy over time, and examine the factors associated with the booster dose of COVID-19 vaccine hesitancy for more validation and application.To improve the acceptance rate of vaccination among hesitant groups, there is a need for new regulations to be issued and run by the government and the public health authorities through educational framework to provide significant scientific information about the booster dose of the COVID-19 vaccine in order to minimize the misleading information spread online by non-official organizations.

TABLE 4 : Willingness or hesitancy toward the third/booster dose of the COVID-19 vaccine among residents of Riyadh, Saudi Arabia Discussion Based
on our knowledge, this is the first cross-sectional study that used a convenience sample of the population in Riyadh, Saudi Arabia, to evaluate public approval of receiving a booster dosage of the COVID-19 vaccine and its contributing factors.Socio-demographic factors showed different sample characteristics.A previous study done in Jordan by Al-Qerem et al. has found that demographic differences influence beliefs and acceptance of COVID-19 booster vaccination