Risk Perception of SARS-CoV-2 Infection and Acceptability of a COVID-19 Vaccine in Nigeria

Background: Vaccines are highly anticipated for the control of the ongoing COVID-19 pandemic, however their acceptance is critical for the desired bene�t. This study assessed risk perception of COVID-19 and acceptability of its vaccine in Nigeria. It also assessed prediction of vaccine acceptance from risk perception. Methods: A cross-sectional web-based study was conducted among 410 participants in the six geo-political regions of Nigeria using a three-part questionnaire developed using Google forms. The questionnaire link was distributed via snowball method to consenting participants through online platforms. Descriptive and inferential statistics (Chi-square and binomial regression) using Microsoft Excel and SPSS version 24 were used to analyze data, and p-values < 0.05 were considered statistically signi�cant. Results: A total of 410 respondents participated in the study and high risk perception of SARS-CoV-2 infection (COVID-19) was seen in 127(66.1%) of respondents. Vaccine acceptance was high in 233(56.8%) of respondents, and was signi�cantly associated with geo-political region (P=0.028). Association between COVID-19 risk perception and vaccine acceptance showed that persons who had high risk perception of COVID-19 may not necessarily accept the vaccine (OR=0.450; 95% CI=0.297– 0.683; P=0.000) and this was seen in persons with tertiary education (OR=0.458; 95% CI=0.297-0.706; P=0.000), married (OR=0.194; 955%CI =0.098-0.386; P=0.000), from South-south (OR=0.352; 95%CI=0.163–0.760; P=0.008) and North-central (OR=0.429; 95% CI= 0.189-0.972; P=0.043). Conclusions: High risk perception of COVID-19, and vaccine acceptance were relatively average. Regional and socio-demographic variations were associated with this �nding, and it was also noted that high risk perception of COVID-19 may not likely result in vaccine acceptance. Strategic and targeted messaging on


Introduction
The coronavirus disease 2019 (COVID-19) pandemic has been a major public health challenge since its initial report in Wuhan, China [1].Its associated negative effects on the economy and human socialisation have impacted on quality of life and psycho-social health of individuals [2].Originating from a novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus − 2 (SARS-CoV-2) [1], speci c drug treatment has remained a challenge, although several drugs have been associated with improved outcomes of the disease [3,4].Therefore, the availability of a safe and effective vaccine against SARS-CoV-2 has become a major public health priority and has been widely anticipated.
Several types of potential COVID-19 vaccines are currently being developed, with a good number of them at the clinical trial phase [5,6].Some of these include, inactivated viral vaccines, non-replicating viral vector vaccine, protein subunit vaccine, replicating viral vector vaccine, Ribonucleic Acid (RNA) based vaccine, virus-like particle, among others [7].Major concerns of COVID-19 vaccines are e cacy and adverse reactions, especially in vulnerable groups of the populations [5].A vaccine is potentially su cient to confer herd immunity in communities and a subsequent control of the pandemic, but this requires high immunisation coverage [8] and a rate of 55 % to 82 % has been estimated for SARS-CoV-2 herd immunity threshold [9].Therefore, for effective control of COVID-19 through vaccination, it is critical to ensure the readiness of the populace and acceptance of the vaccine by a large proportion of the population.Risk perception of the disease could also appreciably determine the acceptability of a vaccine [10].About 156, 000 con rmed cases of COVID-19 has been recorded in Nigeria as at 3rd March 2021, since its rst con rmed case on 27th February, 2020 [11].Although COVID-19 remains an ongoing pandemic with signi cant morbidity and mortality, low mortality and high recovery rates has been recorded in Nigeria [11].Irrespective of the highly infectious nature of SARS-CoV-2, only a few persons appear to be aware of the possibility of contracting the disease in a Nigerian population, with a good number regarding the disease to be exaggerated [12].Denial and misplaced 'religious zealotry' are also perceived to be negatively associated with COVID-19 -related behaviour in Nigeria [13].Although, vaccination is a critical tool for preventing and controlling diseases, low rates of vaccine acceptance has been previously noted in Nigeria [14].Vaccine hesitancy poses a global public health threat, and its acceptance is reportedly associated with the behavioural nature of a people [15].Studies have shown that vaccine acceptability varies across the globe [16,17], therefore adequate understanding of key determinants of COVID-19 vaccine acceptability is necessary for the development of effective global vaccination programme.
It is evident that acceptance of a COVID-19 vaccine is a major public health need in the effective control of the disease.Lower risks perceptions of COVID-19 may in uence the potential willingness to accept it.
This study assessed the risk perception of COVID-19, and acceptability of a COVID-19 vaccine among the Nigerian population.Also studied were associations between respondents' socio-demographic characteristics and vaccine acceptability.Probability of COVID-19 vaccine acceptance as a result of COVID-19 risk perception, was also evaluated.It is hoped that ndings from this study will equip public health professionals and policy makers with insights and relevant information that can be used for optimal COVID-19 vaccine rollout.

Study design and study setting
A cross-sectional web-based study was conducted from 20 th November, 2020 to 28 th December, 2020 to ascertain the risk perception of COVID-19 and the acceptance of the vaccine in Nigeria.The authors formulated and tested a hypothesis which states that high risk perception of COVID-19 may not imply acceptance of the vaccine.
Nigeria is located in West Africa with over 250 ethnic groups and is divided into six geopolitical zones and the Federal Capital Territory (FCT).Each geo-political region is made up of 6 States, except the northwest and southeast regions which consist 7 and 5 states respectively.It is the most populous Black Country with a population of over a 200 million.The country had an average life expectancy of 54 years as at 2018 [18] and has been previously faced with several disease outbreaks.

Study population
With a Nigerian population of about 200, 000, 000 [19], a vaccine acceptance of 50 % and margin of error of 5 % (95 % CI), we calculated a sample size of 385 individuals [20], but 10% was added to account for potential non-responses or attrition, and the study was then conducted among 420 participants.
The study included both male and female Nigerians who resided in Nigeria, who had access to internet facilities, and who belonged to online groups.It however excluded persons who did not give informed consent for the study and persons who were less than 18 years of age.

Survey Instrument
Acceptability of a COVID-19 vaccine may be dependent on the associated risk perception of the disease.The questionnaire design was based on this theoretical frame work, and was composed of questions that explored and evaluated the risk perceptions of the respondents about COVID-19 and the willingness to accept the vaccine by the respondents.
A three-part researcher-developed questionnaire which required about 2 minutes to complete was designed using Google forms.The constructs measured by the questionnaire were the respondents' risk perception of COVID-19 and the acceptability of a COVID-19 vaccine.Section A of the questionnaire had 7 questions which obtained information on respondents' basic socio-demographic characteristics.Section B consisted of 5 questions and elicited information on respondents' risk perception of COVID-19.Section C was composed of 5 questions which assessed respondents' acceptability of a vaccine respectively.The questions were anchored on a 5-point Likert scale that ranged from strongly agree to strongly disagree."SARS-CoV-2 infection" was not used in the questionnaire, "COVID-19" was rather used to facilitate comprehensibility.
The questionnaire was validated by expert evaluations and preliminary tests.Three public health experts assessed their suitability by face validity, and the preliminary testing was conducted among twenty adults who were randomly selected within the six geopolitical regions of Nigeria.This enabled the veri cation of proper understanding of the questions, and modi cations were made to questions that were deemed to be ambiguous.The reliability of the survey tool was also assessed using Cronbach's alpha.

Data collection and study outcome measures
The internet link was distributed to consenting participants through online platforms.Snowball approach was adopted in the distribution of the internet link via social media platforms and the survey was closed after 6 weeks of data collection.The outcome measures for the study were acceptance rates of a COVID-19 vaccine by the study participants and risk perception of COVID-19.

Data analysis
Online survey data were downloaded into Microsoft Excel spreadsheet for data cleaning, validation and descriptive analysis.Determination of the survey sample characteristics was performed by descriptive statistics (frequencies, percentages).The assessment of perceived risk and vaccine acceptability which both had a 5-point Likert scale was interpreted as: "Strongly disagree", "Disagree" and "Undecided" = 0, while "Strongly agree" and "agree" for each question on risk perception and potential vaccine acceptability, was scored as 1 and the scores were added together.Weighted analyses for COVID-19 risk perception and COVID-19 vaccine acceptability were performed.Weighted scores were totaled over 5, and higher scores (≥ 3) denoted "high risk perception" and "vaccine acceptance" (pro-vaccination) respectively.Low scores (≤ 2) represented "low risk perception" and "vaccine unacceptance" (antivaccination).
Data were imported to SPSS version 24 where inferential statistics was performed.Pearson's Chi Square analysis was completed to determine associations between socio-demographics and vaccine acceptability.Binominal logistic regression was also conducted at 95 % con dence interval to evaluate and predict vaccine acceptance from COVID-19 risk perception (p ≤ 0.05 was considered signi cant).

Ethical statement
Ethics approval was obtained from the Ethical unit of the Kwara State Ministry of Health and had the reference number MOH/KS/EU/777/455.Informed consent was obtained from the study participants prior to the study.The rst part of the online survey instrument had a clear statement to show that participation in the study was completely voluntary.As also stated on the rst part of the survey, consent for study participation was implied by clicking on the link and submitting the completed form.Forms were lled and submitted anonymously and con dentiality of the participants' information was ensured during and after the study.

Results
A total of 420 respondents participated in the survey, but 10 were excluded as the participants did not reside in Nigeria.The Cronbach's alpha showed a reliability of 0.82.Socio-demographic characteristics of the respondents is shown in Table 1.Majority of the study participants were male 241 (58.8 %), aged between 26-35 years old 175 (42.7 %), single 240 (58.5 %), employed 301 (73.4 %), had tertiary education 371 (90.5 %) and from the North-central region of Country 133 (32.4 %) See Table 1.
Table 3 shows acceptability of COVID-19 vaccine by the respondents, where the total weighted acceptance of the vaccine was 233 (56.8 %), therefore almost half 177 (43.2 %) would not accept it.
Majority would accept a COVID-19 vaccine if substantial information accompanied it 260 (63.4 %), if it were recommended by their healthcare provider 283 (69.3 %) and if it was provided at no nancial cost 239 (58.3 %).Conversely, less than half 173 (42.2 %) would accept it irrespective of its novelty, and only about a one third of the population 134 (32.7 %) will readily accept the vaccine regardless of its potential adverse effects.See Table 3.
Details of the socio-demographic association of COVID-19 vaccine acceptability is given in Table 4. Acceptability of the vaccine was not signi cantly associated with gender (P = 0.846), age (P = 0.073), marital status (P = 0.105), employment status (P = 0.293) and educational quali cation (P = 0.556), but was associated with geo-political region (P = 0.028).Over half of the males 136 (56.4 %) and females 97 (57.4 %) would accept the COVID-19 vaccine in Nigeria.Meanwhile, more than half of persons between 36-45 years old 49 (54.4%) and persons above 55 years old 5 (62.5%), would not accept the vaccine.Similarly about half 83 (49.7%), of the married respondents would not accept the COVID-19 vaccine, while majority 147 (61.3%) of the single respondents would accept it.Findings from the study show the region with the highest acceptance rate to be the North-east 11 (73.3%) and the region with the least acceptance rate to be the North-west 6 (37.5%).Over half of persons from the South-east 22 (57.9%),South-west 49 (55.1 %), North-central 85 (63.9 %), and almost half of persons in the South-south 55 (48.2 %), would accept the vaccine.See Table 4.

Discussion
High risk perception of COVID-19 was observed in majority of the respondents.Similarly, ndings from a previous study also reported poor perception of COVID-19 in Nigeria [12].The impact of an infectious disease may be dependent on perceptions about the disease.Therefore, following the high infectivity, and associated morbidity and mortality of SARS-CoV-2, improving its risk perception by health education measures is essential.In an Iranian and a Nigerian study, socio-demographic factors were reported to be determinants of COVID-19 risk perception [21,22], which re-enforces the need for targeted messaging by stake holders.
Findings from this study indicate that almost half of the study participants will likely not accept a COVID-19 vaccine, which is in congruence with a previous study in Nigeria [23,24].This level of the vaccine acceptance may not be su cient for COVID-19 herd immunity.COVID-19 vaccine acceptance in United States of America had higher acceptance rate than ours [25].This difference may be associated with varying levels of risk perceptions among the populace, and the overall COVID-19 associated morbidities and mortalities in the two countries.Nigeria has recorded about one hundred and fty thousand con rmed cases, majority of who had been discharged, with very few deaths [11].A global survey found that potential acceptance of the vaccine varied among countries with China and Russia having the highest and least acceptance rates respectively [16][17].
Our study suggests that majority of persons may be cautious of the potential adverse effects of a COVID-19 vaccine, and this may be a major limiting factor to its acceptance.Similarly, almost half of the persons who would accept the vaccine in China also considered con rmation of vaccine safety as a necessity for receiving a dose of it [17].Considering that healthcare providers may have a positive in uence on the vaccine acceptance through their recommendation as seen in our study, it is pertinent to seek their total commitment regarding information on potential adverse reactions of the vaccine.This may build trust in the public and enhance vaccine acceptance.
In this study, acceptance of COVID-19 vaccine was not signi cantly associated with gender, age, marital status, employment status and educational quali cation, but was associated with geo-political region.In a recent study, age and gender were also reported not to be associated with COVID-19 vaccine acceptance in Nigeria [24].Conversely, it was reported that gender and marital status could enhance the likelihood of COVID-19 vaccine acceptance in China [17].Signi cant differences in socio-demographic associations with COVID-19 vaccine acceptance were also observed in the United States [25].In our study, vaccine acceptance was majorly noted to be associated with geographic regions, this is suggestive of the need for targeted educational interventions in the regions, with effective COVID-19 vaccine-acceptance detailing, via various media.As a result of varying educational levels in the regions, this signi cant association is not unexpected.However, without adequate interventions, this could impair the formation of herd immunity threshold for SARS-CoV-2 [9] in the country.Basic interventions may include building trust on the vaccine, through consistent thoughtful and targeted public health information.
The study found that high risk perception of COVID-19 may not necessarily result in COVID-19 vaccine acceptance.This was especially seen across the sexes, persons from the South-south and North-central region of the country and persons who had tertiary education.In contrast, high risk perception of infection was reported to potentially increase vaccine acceptance in China [17] and in United States of America [26].Perception of risks of COVID-19 is expected to enhance the uptake of precautionary behaviours [27] including vaccine acceptance, however several factors have been noted to in uence this contrast in Nigeria.Among these recognised factors are mistrust of vaccine intentions [14], denial and religious beliefs [13].
The study was faced with some limitations among which may be selection bias, following the online method of data collection which may have excluded persons in rural communities with no internet facility and older adults who may not be friendly with social media applications.Therefore, this may have overestimated the rate of acceptability of the vaccine, thereby limiting the generalisation of our ndings.Also, low response rate recorded in the North-east and North-west regions may limit the generalisation of the ndings in this region.Lastly, merging the "undecided" group with the "disagree" and "strongly disagree" groups may have caused losses of some statistical outcomes during dichotomisation of COVID-19 vaccine acceptance.However, the study buttressed the probability of vaccine acceptance from high risk perception of COVID-19, across socio-demographic variables.

Conclusion
High risk perception of COVID-19 was found in over half of the respondents.Similarly, COVID-19 vaccine acceptance rate was found to be a little over 50%.However, the study noted regional association with vaccine acceptance among the study participants, and also observed that high risk perception of COVID-19 may not likely result in vaccine acceptance among several socio-demographic groups.Therefore, more targeted and strategic educational interventions is necessary to improve risk perception and acceptance of COVID-19 vaccine, in other to break the disease transmission dynamics.

Table 1
Socio-demographic characteristics of respondents.

Table 4
Associations between vaccine acceptability and respondents socio-demographic characteristics.

Table 5
Probability of COVID-19 vaccine acceptance from high risk perception of COVID-19.