Pro-Vaccination Attitude and Associated Factors Towards COVID-19 Vaccine among Healthcare Workers and Nonhealthcare Workers: “A Call for Action”-A Systematic Review

Introduction: Coronavirus disease 2019 (COVID-19) pandemic hasn’t been managed and controlled effectively, globally. The aim of this systematic review was to determine Pro-vaccination attitude and associated factors towards COVID-19 vaccine among healthcare workers (HCWs) and nonhealthcare workers (non-HCWs). Methods: Different databases such as PsycINFO, HINARI, Cochrane Library, PubMed, EMBASE, African Journals OnLine, Web of Science, Scopus, and Google Scholar for the related articles. Result: The levels of positive attitude towards COVID-19 vaccine among HCWs was ranged from 21% to 95%. Factors signi�cantly associated with the attitude towards COVID-19 vaccine among HCWs were such as age, gender, race, work experience, home location, having no fear of injections, being a non-smoker, profession, presence of chronic illnesses, allergies, con�dence in pharmaceutical companies, history of taking in�uenza vaccine, vaccine recommendation, perceived risk of new vaccines, perceived utility of vaccine, receiving a seasonal �u vaccination in the last 5 years, working in a private hospital, a high perceived pandemic risk index, low vaccine harm index, high pro-socialness index, being in close contact with a high-risk group, knowledge about the virus, con�dence in and expectations about personal protective equipment and behaviors. The levels of positive attitude towards COVID-19 vaccine among non-HCWs was ranged from 21.4% to 91.99%. Factors associated with the attitude towards COVID-19 vaccine among non-HCWs were such as age, gender, educational level, occupation, marital status, residency, income, ethnicity, risk for severe course of COVID-19, direct contact with COVID-19 at work, being a health profession, being vaccinated against seasonal �u, perceived bene�ts, cues to actions, having previous history of vaccination, fear of passing on the disease to relatives, and the year of medical study, studying health-related courses, COVID-19 concern, adherence level to social distancing guidelines, history of chronic disease, being pregnancy, perceived vaccine safety, having more information about vaccine effectiveness, mandatory vaccination, being recommended to be vaccinated, lack of the con�dence in the healthcare system to control epidemic, and believe in COVID-19 vaccines protection from COVID-19 infection. Conclusion: The level of positive attitude towards COVID-19 vaccine among both HCWs and non-HCWs were unfavorable and comparable. Globally, there is a need for a call for action to cease the time and crisis of this pandemic.

Introduction COVID-19 pandemic has spread swiftly over all countries [1]. COVID-19 remains to destroy the world [2]. This pandemic has put a challenge across all the countries [3], since it was described as a pandemic [4]. It is a worldwide public emergency [5]. It affected all persons globally [6]. COVID-19 put a signi cant burden comprising morbidity and mortality [7,8]. It has also led to substantial economic disasters besides mortality and morbidity [9]. This pandemic has also led to mental health worsening of the families who had children [10], the entire population [11], and also massive effect mental health of the youth [12]. It has also incredibly affected the development of children [13], and markedly interrupted vaccination of the children [14]. Furthermore, this pandemic has also momentous stress on patients, healthcare systems, and HCWs [15]. It has also affected the treatment and prevention of chronic cases such as tuberculosis and human immunode ciency virus [16].  Exclusion criteria Articles which didn't assess the outcome variables, articles which were not fully accessible, and articles with poor quality were excluded from this systematic review.

Outcome Interest
In this systematic review, the primary outcome was the prevalence of Pro-vaccination attitude towards COVID-19 vaccine among HCWs and non-HCWs. Pro-vaccination attitude was measured by using a "Yes" or "No" question. "Do you intend to have a COVID-19 vaccine in the future?" was the question asked to the participants. The secondary outcome was factors associated with Pro-Vaccination Attitude towards COVID-19 vaccine among HCWs and Non-HCWs which was reported within the included studies.

Data Extraction and Quality Assessment
The retrieved articles from all databases were exported to Thomson Reuters EndNote version 8. The title and abstract of all possible articles to be included in this systematic review were checked. The standardized data extraction format prepared in a Microsoft Excel worksheet was used to extract the data from the selected articles according to the pre-setted inclusion criteria. The names of the authors, publication year, study period, study country, participants, sample size, study design, prevalence, and factors were used for the extraction of data from each article.
This systematic review has only included cross-sectional studies. The Newcastle-Ottawa Scale (NOS) quality assessment criteria for cross-sectional studies were used to assess the included articles [42,43], and the modi ed NOS for cross-sectional studies was used to include the articles. Whereas, all articles with ≥5 out of 10 were considered as a high quality score [44], and included in to this systematic review.

Data Synthesis and Reporting
This systematic review was conducted on Pro-Vaccination Knowledge, Attitude, and Associated Factors Towards COVID-19 Vaccine among HCWs and Non-HCWs. During this, the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) owchart diagram [45,46], and PRISMA checklist [46] were used for the study screening, selection, and inclusion in to this systematic review.

Ethics Approval and Consent to Participate
Not applicable. Since this is a systematic review, there was no data collected from the people.

Search Results
All related studies done across the worldwide were identi ed by using diverse databases. Those databases used to search the related studies were PsycINFO, HINARI, Cochrane Library, PubMed, EMBASE, African Journals OnLine, Web of Science, Scopus, and Google Scholar. From the search made through all these databases, 9,325 studies were found. Due to the duplication found, 4,512 studies were excluded. From the remaining 4,813 studies, 3,835 and 876 studies were omitted because of the titles and abstracts, respectively after carefully checked for their relativeness. A total of 102 studies were screened for eligibility as the pre-setted eligibility criteria. From these, 29 studies were excluded due to lack of the full text, 17 studies were excluded due to the outcome of interest was not well de ned, and 8 studies were excluded due to poor quality. Afterwards, 48 studies were met the prede ned eligibility criteria and included in to this systematic review ( Figure 1).

Study Characteristics
This systematic review focused on the studies conducted on Attitude regarding COVID-19 vaccine and its associated factors among the two major population categories, HCWs and non-HCWs. In this systematic review, a total of 48 studies were included, comprising the studies done on both HCWs and non-HCWs participants. There have been substantial differences concerning to the level of attitude towards COVID-19 vaccine among both populations (Table 1).

Attitude Towards COVID-19 Vaccine Among HCWs
From the total of 48 studies included in to this systematic review, only 19 studies were conducted among HCWs. The smallest and largest sample sizes were reported from Germany (200) [47], and United States (US) (5,287) [48], respectively. The smallest prevalence of a positive attitude towards COVID-19 vaccine among HCWs were reported as 21% from Egypt [49], while the largest prevalence was 95%, which was reported from Asia-Paci c [50]. Thus, the prevalence of a positive attitude towards COVID-19 vaccine among HCWs was ranged from 21% [49] to 95% [50].
Factors signi cantly associated with the attitude towards COVID-19 vaccine among HCWs were age, gender, race, work experience, home location, having no fear of injections, being a non-smoker, profession, presence of chronic illnesses, allergies, con dence in pharmaceutical companies, con dence in the management of the epidemic, history of taking in uenza vaccine, vaccine recommendation, perceived risk of new vaccines, perceived utility of vaccine, receiving a seasonal u vaccination in the last 5 years, working in a private hospital, a high perceived pandemic risk index, low vaccine harm index, high pro-socialness index, using Facebook as main information source about antiSARS-CoV-2 vaccination, being in close contact with a high-risk group, having undertaken seasonal u vaccine during the 2019-2020 season, role within the hospital, knowledge about the virus, con dence in and expectations about personal protective equipment and behaviors (Table 1).

Attitude Towards COVID-19 Vaccine Among Non-HCWs
Concerning to the non-HCWs, a total of 29 studies were conducted among non-HCWs from 48 studies included in to this systematic review. The smallest and largest sample sizes were reported 90 from United states of America [51], and 32,361 from United kingdom [52], respectively. The smallest prevalence of a positive attitude towards COVID-19 vaccine among non-HCWs were reported as 21.4% from Lebanon [53], while the largest prevalence was 91.99%, which was reported from Poland [54]. Thus, the prevalence of a positive attitude towards COVID-19 vaccine among non-HCWs was ranged from 21.4% [53] to 91.99% [54].
Factors associated with the attitude towards COVID-19 vaccine among non-HCWs were age, gender, educational level, occupation, marital status, residency, income, ethnicity, risk for severe course of COVID-19, direct contact with COVID-19 at work, being a health profession, being vaccinated against seasonal u, perceived bene ts, cues to actions, having previous history of vaccination, fear of passing on the disease to relatives, and the year of medical study, studying health-related courses, COVID-19 concern, adherence level to social distancing guidelines, history of chronic disease, being pregnancy, perceived vaccine safety, having a close acquaintance who did not experience a vaccine-related adverse reaction, having more information about vaccine effectiveness, mandatory vaccination, being recommended to be vaccinated, lack of the con dence in the healthcare system to control epidemic, heard about COVID-19 vaccines, believe in COVID-19 vaccines protection from COVID-19 infection, those who encouraged their family members and friends to get vaccinated (Table 1).

Discussion
Despite the fact that more than a year has passed since the WHO stated a COVID-19 pandemic, there is no effective treatment yet. The only strategy to halt the virus from spreading is the vaccination of the population as per the recent evidence. However, more populations should to be vaccinated to achieve herd immunity. This is a substantial contest for healthcare systems. Having an effective vaccine is not equivalent to using it, public acceptance is crucial [94]. Besides, despite the consideration of vaccination good achievements of the 20 th century, there are remaining public health issues including insu cient, delayed, and unstable vaccination uptake [95]. Generally, the willingness to take the vaccine against COVID-19 will be the next main phase in ghting this pandemic. However, attaining signi cant uptake will be a contest [96]. Hence, this systematic review was intended to determine the Pro-vaccination attitude and associated factors towards COVID-19 vaccine among HCWs and Non-HCWs globally.
This systematic review has included cross-sectional studies done on the attitude towards COVID-19 vaccine and its associated factors among HCWs and non-HCWs. Recognizing the level of attitude towards COVID-19 vaccine and its associated factors among concerning these two major populations would have a substantial role in managing and controlling this pandemic. This is due to that this study provides critical evidences at the time of this global crisis, which is because of the adverse effects of the COVID-19 pandemic. This is supported by the study which explains that knowing the public needs and factors determining their attitudes towards vaccines would assist to plan for multilevel interventions depending on the evidence to improve vaccine uptake, globally [97]. Generally, to predict and be ready for the future epidemic and pandemic reply, it would be crucial to understand how populations approach the emerging infectious diseases [98].
From the total of 48 studies included in to this systematic review, only 19 studies were conducted among HCWs. The results of this systematic review showed that there was a substantial discrepancy on the level of attitude towards COVID-19 vaccine among HCWs and non-HCWs globally. The level of positive attitude towards COVID-19 vaccine among HCWs was ranged from 21% [49] to 95% [50]. This nding demonstrates that there is a crucial problem that needs to be addressed in high priority to cease the era of the current pandemic. This is due to that HCWs are at high risk of COVID-19 [39]. This infection in HCWs would have an instant consequence on their occupation and the entire healthcare system [38].
Generally, the ndings of this systematic review showed that several factors have been associated with the attitude towards COVID-19 vaccine among both HCWs and non-HCWs. This is because of that even though the immunization coverage is described administratively across the world, no likewise vigorous monitoring system occurs for vaccine con dence. There is rising evidence of vaccine denial because of the lack of trust in the bene ts, safety, and effectiveness of vaccines [99]. The acceptance of a COVID-19 vaccine was vastly affected by the effectiveness of the vaccine [100]. Besides, if people lack enough knowledge towards the vaccine, this might lead to negative attitudes about it, which will avoid it to accept the vaccine. If communication efforts fail to address vaccine-negative persons', the liberty-associated concerns may not be successful [101]. Even, the political talk was found to have a signi cant effect on the attitudes of individuals. For instance; this study showed that political talk plays a considerable role in shaping and polarizing attitudes on stem cell research [102]. The intention to accept this vaccine maybe affected by online misinformation, it is signi cantly associated with failures in vaccination intent [96]. Furthermore, vaccine-related conspiracy theories could affect the attitude of individuals towards the vaccine. This is supported by the experimental study conducted in China [103]. Moreover, according to the planned behavior theory, attitudes regarding to behavior, subjective norms of behavior, and perceived control over behavior forecast behavioral willingness, while this willingness together with perceived behavioral control accounts for a substantial proportion of variance in behavior [104]. Finally, even though, it is expected that the attitude towards COVID-19 vaccine among HCWs will be greater than that of non-HCWs, the ndings of this systematic review indicated that the level of positive attitude towards COVID-19 vaccine among HCWs and non-HCWs was comparable.

Recommendations
The acceptance of vaccines against COVID-19 is a vital to ght this pandemic [105]. Hence, to rise the vaccination, considering the psychological science of action is suggested. It can be applied through; thoughts and feelings, social processes, and interventions can facilitate vaccination [95]. From the theory of normative conduct, norms have a substantial role in shaping human behavior. Thus, to improve the probability of socially bene cial behavior in others via norm activation would be well advised [106].