Knowledge, Awareness and the Willingness to accept the RTS,S/AS01 malaria vaccine among mothers of under-five children in Lagos, Nigeria

doi:10.21203/rs.3.rs-4934807/v1

Background of the study: In October 2021, the World Health Organisation (WHO) recommended the use of RTS, S/AS01 malaria vaccine among children in sub-Saharan Africa and in other regions with moderate to high P. falciparum malaria transmission. This study aimed to investigate the willingness to receive RTS, S malaria vaccine as well as the knowledge and awareness of this vaccine among mothers of children under five years of age in Lagos, Nigeria.

Methodology: This was a cross-sectional survey comprising structured questionnaires administered to mothers of children under the age of five attending immunization clinics in selected local government areas of Lagos, Nigeria (Alimosho, Ikeja, Kosofe, Ikorodu and Surulere). The study was conducted between February and May, 2023. Logistic regression analysis was used to determine the predictors of the likelihood of receiving the RTS, S malaria vaccine. A total of 395 mothers completed the survey.

Results: The awareness of the RTS, S malaria vaccine among mothers of under-five children is fairly low (48%) in Lagos. However, more than two-thirds of the mothers (84.8%) were willing to accept the RTS, S malaria vaccine for their children.

Surprisingly, mothers who are undecided on the possibility for the vaccine to infect their children with malaria were nine (9) times likely to accept the RTS/S malaria vaccine compared to those who are certain that the vaccine would not infect their children with malaria (OR = 9.075, 95CI% = 01.275–64.581, p = 0.028). Moreover, mothers that are aware of the RTS/S malaria vaccine (OR = 3.033, 95CI% = 1.366 –, 6.735, p < 0.05) are three (3) times more likely to accept the vaccine compared to those that are not aware of the vaccine.

Conclusion: The findings of this study revealed the urgent need to increase awareness about the RTS, S malaria vaccine and assure mothers of under-five children of its safety. There is also a need for the Nigerian government to secure a large number of malaria vaccine doses since a majority of the mothers believe that the vaccine should be included in routine immunization.

malaria vaccine

vaccine hesitancy

mothers of under-five children

RTS/S malaria vaccine

Nigeria

Vaccination is an effective way to prevent malaria in addition to the use of insecticides, insecticidal nets and prophylactic antimalarials (1). In October 2021, the World Health Organisation (WHO) recommended using the RTS,S/AS01 malaria vaccine among children in Sub-Saharan Africa and other regions with moderate to high P. falciparum malaria transmission. This recommendation was based on a pilot study conducted in Ghana, Kenya, and Malawi. (2)

The RTS,S is a malaria vaccine developed by GlaxoSmithKline (GSK) through a partnership with the PATH Malaria Vaccine Intervention funded by the Bill and Melinda Gates Foundation. It is the first approved malaria vaccine that has proceeded to phase IV clinical trials (3).

There are three types of malaria vaccines based on the parasite developmental stage they target – pre-erythrocytic vaccines, blood-stage vaccines, and transmission-blocking vaccines. RTS,S is a pre-erythrocytic vaccine that targets circumsporozoite protein (CSP) on the sporozoite surface and P. falciparum parasites before they invade the liver cells (4). Disruption of the cycle at the first developmental stage prevents progression to other stages making it an effective vaccine (4).

The vaccine is presented as a lyophilized antigen in a vial to be reconstituted with AS01 in another vial and administered intramuscularly (5). Both must be stored between 2 and 8 ^oC. The adjuvant, AS01 is sensitive to temperature because its components are prone to hydrolysis. A total of four (4) doses are administered in children - the first 3 doses are given monthly, with the first dose given at 5 months of age and the third completed by 9 months of age. The fourth dose is administered at 15–18 months.

The RTS, S vaccine comprises the hepatitis B surface antigen as its carrier matrix for the circumsporozoite (CSP) central repeat region fused with the CSP C-terminal region containing T- and B- cell epitopes based on the P. falciparum NF54 strain (4). Several adjuvants majorly from GSK’s adjuvant systems have been tested with RTS, S.

Adjuvants are components that improve vaccine immunogenicity and efficacy by promoting antigen presentation to antigen-specific immune cells to confer long-term protection against targeted pathogens (6). AS02 is an oil-in-water emulsion–based formulation while AS01 is a liposome-based formulation. A study conducted in the United States showed that RTS,S/AS01 induced greater levels of anti-CS antibodies and CS-specific T-cell than RTS,S/AS02, and thus, may confer greater protection against the infection (7).

According to the World Health Organization (WHO) 2022, World Malaria Report, the estimated number of malaria cases increased from 245 million in 2020 to approximately 247 million in 2021. Twenty-nine (29) countries accounted for 96% of all cases globally, and four countries – Nigeria (27%), the Democratic Republic of the Congo (12%), Uganda (5%), and Mozambique (4%) – accounted for approximately half of these cases (WHO, 2022). This shows that Nigeria bears the highest burden of malaria disease in the world (8).

The percentage of households with insecticide-treated nets (ITNs) has also increased over the years (9). However, the increase in partial resistance to ACT and resistance of vectors to insecticides and insecticide-treated nets (ITNs) has been a major challenge in combating malaria especially in Africa. Moreover, the invasion of a mosquito species, Anopheles stephensi which adapts easily to urban areas and is resistant to many insecticides, in sub-Saharan Africa where more than 40% of people live in urban areas, compounds the challenges encountered in combating malaria (9). A new initiative was launched to stop the further spread of this mosquito and elimination from regions where it has already invaded. Research is ongoing to address issues of resistance to the antimalarial drugs and ITNs, including reduced sensitivity of the parasite to available diagnostic tests (10).

In a joint news release by Gavi, the WHO, and UNICEF on July 5, 2023, it was stated that twelve countries are going to receive a total of 18 million doses of RTS,S/AS01 for the period of two years (2023–2025). Nigeria is not part of these countries as she missed the second application window (January 17, 2023) but was able to apply during the third window which ended on April 18, 2023. The Minister of Health for the Federal Republic of Nigeria, said that the vaccine should be expected in the country by April 2024. A second malaria vaccine, R21/Matrix-M has being reviewed and recently recommended by the WHO. This could help close the supply gap of the limited RTS,S doses since up to 100 million doses of Matrix-M would be made available.

Despite these WHO recommendations, RTS,S/AS01 (Mosquirix ®) and any other malaria vaccine can still suffer from setbacks such as some previous vaccination exercise in Nigeria due to vaccine hesitancy and outright refusal of the vaccine among the target groups of individuals (11). The World Health Organization defines vaccine hesitancy as a “delay in acceptance or refusal of vaccines despite the availability of vaccination services” (12). Decision-making around vaccination entails a complex mix of cultural, psychosocial, spiritual, political, and cognitive factors (13). The reasons for vaccine hesitancy can be divided into three categories: lack of confidence (in effectiveness, safety, the system, or policymakers), complacency (perceived low risk of acquiring VPDs), and lack of convenience (in the availability, accessibility, and appeal of immunization services, including time, place, language, and cultural contexts) (14).

This study was designed to assess the knowledge, awareness, and willingness of mothers of children under five years of age in Lagos, Nigeria to receive the RTS,S/AS01 malaria vaccine. A high rate of vaccine hesitancy in this category of individuals will result in the outright failure of the RTS,S vaccine despite the large resources invested in its development. Thus, a concerted effort will be required to change the narrative and instill confidence in this category of individuals to accept the RTS, S vaccine.

Study design

This was a cross-sectional survey comprising of structured questionnaires administered to mothers of children under the age of five attending immunization clinics in selected local government areas of Lagos State. The study was conducted between February and May, 2023.

Study Setting

This study was carried out in Lagos State, one of the six south-western states in Nigeria. Lagos State is the commercial capital of Nigeria and the second most populated state in Nigeria. Politically, Lagos State is divided into three Senatorial districts; Lagos West, Lagos East and Lagos Central. There are twenty (20) local government areas (LGAs) in Lagos 16 of which are classified as urban and four (4) as rural. It also has thirty-seven (37) local council development areas (LCDAs) which are responsible for taxation, schooling and health. It is populated by mainly by the three major tribes of Nigeria (Yoruba, Hausa and Igbo). Although the major dialect is Yoruba, the official language is English and healthcare services is provided in this official language. According to Kuyinu et al., (2020), Lagos state has a population growth rate of 600,000 people per annum and a population density of 4193 people per square kilometer (15).

Sampling Procedure

A cluster sampling technique was used to divide the study area into three Senatorial districts (Lagos West, Lagos East and Lagos Central). At least one LGA was then selected from each of the districts. Alimosho and Ikeja LGAs were chosen from Lagos West. Kosofe and Ikorodu LGAs were chosen from Lagos East and Surulere LGA was chosen from Lagos Central. After the selection of the five LGAs, one immunization clinic at a major healthcare provider were selected as the study sites for each of the five LGAs. Thus, the immunization clinics of Aregbesola Primary Health Centre, Lagos State University Teaching Hospital, Gbagada General Hospital, Ikorodu General Hospital and Coker-Aguda Primary Health Centre were chosen from Alimosho, Ikeja, Kosofe, Ikorodu and Surulere LGAs respectively. The questionnaires were administered on the clinic days of these healthcare facilities through an instructor-led interview. Overall, 392 was calculated as the minimum sample size (16), but 413 questionnaires were administered. Out of this, 395 were deemed to be adequately completed. A pilot study was done to check the suitability of the questionnaire before the study.

Inclusion and exclusion criteria

Respondents who were adult females and mothers of a child (ren) less than five years old were included in the study. In addition, respondents must also visit one of the immunization clinics designated for the study within the data collection period. Other respondents who do not fall into this category were excluded.

Data Collection

The data were collected through an instructor-led interview using the questionnaire. The data were collected by the researchers and two other trained data collectors. The structured questionnaire has four sections: 1. sociodemographic characteristics of respondents, 2. Attitudes to previous vaccination, 3. Knowledge and awareness of the RTS, S malaria vaccine, and 4. Perception and willingness to accept the RTS, S malaria vaccine.

The ‘sociodemographic’ section assessed age, marital status, monthly income, ethnicity, educational status and whether a respondent has a child less than the age of five. The questions on the attitudes toward previous vaccination includes if respondents accept to vaccinate their child or children against vaccine preventable diseases and what form of challenges they experience while vaccinating their children. In the ‘Knowledge and awareness of RTS, S malaria vaccine’ section, respondents were asked if they are aware of the RTS, S malaria vaccine and what the sources of their knowledge are. Finally, in the ‘Perception and willingness to accept the RTS, S malaria vaccine’ section, questions were asked with options grouped on a 5-point Likert scale (strongly agree, agree, neutral, disagree and strongly disagree). These questions examined the willingness of respondents to accept the malaria vaccine, whether the vaccine should be included in routine immunization and whether respondents will be willing to pay out-of-pocket for the vaccine among others.

Ethical Consideration

The ethical clearance for this study was obtained from the Lagos State University Teaching Hospital Health Research Ethics Committee with Reference Number: LREC/06/10/2053. The participants (mothers) were briefly informed of the objectives of the study and its potential benefits for the public health system in Nigeria. There were minimal risks to participants as no invasive procedure was involved. Verbal informed consent was obtained from each participant prior to enrollment in the study.

Statistical analysis

The generated data were cleaned, coded and analyzed using Statistical Package for Social Sciences version 23 (SPSS Inc., Chicago IL). Before the analysis, the independence of variables was analyzed using a correlation matrix. Responses to the perception of and willingness to receive the malaria vaccines were combined in one category. For example, responses “strongly agree” and “agree” were combined. This process was repeated for responses “strongly disagree” and “disagree”.

The main outcome of the study was the willingness of mothers of children under the age of five to receive the RTS,S vaccine for their. To determine the factors that influence the willingness to receive the malaria vaccine among the target population, binary logistic regression was performed. First, the potential predictors for the acceptance of the RTS, S malaria vaccine were screened using univariate analysis and variables with p < 0.05 were considered in the binary logistic regressions. Thereafter, the participants’ responses were dichotomized as acceptable or unacceptable in the binary regression model. In both models, the odds ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated. A p-value less than 0.05 was considered to indicate statistical significance.

Sociodemographic Characteristics of Study Participants

The questionnaires analyzed for this study were completed by a total of 395 mothers. A total of one hundred and twenty-eight (128) (32.4 %) of these participants were from the immunization clinic of LASUTH, 94 (23.8 %) from the Gbagada General Hospital immunization clinic, 60 (15.2%) from the Ikorodu General Hospital Immunization clinic, 58 (14.7 %) from Aregbesola Primary Health Centre immunization clinic and 55 (13.9 %) from Coker-Aguda Primary Health Centre immunization clinic.

Approximately half of the mothers (49.9%) were between the age of 30 to 39 years. The majority of the mothers are married (86.3%). Additionally, those with postsecondary education were the majority (71.3%), while those with no formal education are in the minority (0.8%).

All the mothers have a child or children under the age of five (100%) while the majority of them works in the private sector or are self-employed (33.4%). In addition, a majority of the mothers are from the Yoruba ethnicity group (55.2%) – Mothers of other ethnicities (apart from the three major ethnic groups in Nigeria) includes Ibibio, Igala, Isoko, Urhobo, Ebira, Bini, Edo, Ishan, Kanuri, Ijaw and Efik.

Although, there were five study sites, the mothers reside in different areas of Lagos States. The majority of the mothers resides in Lagos West (46.8%). Detailed demographics are presented in Table 1.

Table 1: Summary of the socio-demographic characteristics of the study participants.

Characteristics	n = 395 (%)
Immunization Clinic
LASUTH	128 (32.4)
Gbagada General Hospital	94 (23.8)
Ikorodu General Hospital	60 (15.2)
Aregbesola Primary Health Centre	58 (14.7)
Coker-Aguda Primary Health Centre	55 (13.9)
Age (years)
< 20	16 (4.1)
20 - 29	150 (38.0)
30 - 39	197 (49.9)
40 - 49	9 (7.3)
50 and above	3 (0.8)
Gender
Female	395 (100)
Male	0 (0)
Marital Status
Single	49 (12.4)
Married	341 (86.3)
Widowed	1 (0.3)
Separated	4 (1.0)
Level of Education
Primary	33 (8.4)
Secondary	77 (19.5)
Postsecondary	282 (71.3)
No formal education	3 (0.8)
Occupation
Trader	99 (25.1)
Civil Servant	96 (24.3)
Private sector/Self employed	132 (33.4)
Artisan	22 (5.6)
Unemployed	46 (11.7)
Ethnicity
Igbo	79 (20)
Hausa	41 (10.4)
Yoruba	218 (55.2)
Others	57 (14.4)
Religion
Christianity	271 (68.6)
Islam	122 (30.9)
Traditionalist	1 (0.3)
Others	1 (0.3)
Residence in Lagos (Senatorial Districts)
Lagos East	136 (34.4)
Lagos West	185 (46.8)
Lagos Central	74 (18.8)

Attitudes Towards Previous Vaccination Exercises

In the present study as shown in Table 2, 97.2% of the mothers agreed to vaccinate their children against vaccine preventable diseases. Additionally, only 5.8% of them are not up-to-date in the routine vaccination of their children. The majority of the mothers vaccinated their children in secondary healthcare facilities (38.5%) and primary health centers (37.7%). Table 2 also shows that of the two parents, the mothers are the majority (75%) in regard to taking a child to the vaccination centers for immunization purposes.

Finally, Figure 1 depicts the major challenges faced by mothers while vaccinating their children in Lagos, Nigeria. This revealed that the three major challenges to the immunization of children in Lagos are; busy work schedules (38.3%), long distances to vaccination centers (25.7%) and lack of awareness about the vaccination exercises (25.1%). Other challenges noted by the mothers includes; unavailability of vaccines at immunization centers and delays by healthcare workers at the immunization center.

Table 2: Attitudes toward previous vaccination exercise

Attitude	n= 395 (%)
Do you accept vaccinating your child (ren) against vaccine-preventable diseases?
Yes	384 (97.2)
No	7 (1.8)
Sometimes	4 (1.0)
Are you up-to-date in the routine vaccination of your child(ren)?
Yes	372 (94.2)
No	23 (5.8)
Which category of hospital do you take your children for the routine vaccinations?
Primary Health Centre	149 (37.7)
Secondary healthcare facilities	152 (38.5)
Teaching Hospitals/Tertiary Healthcare institutions	94 (23.8)
Who takes the children for vaccinations?
Mother	304 (77.0)
Father	16 (4.1)
Both parents	75 (19.0)

Awareness and Knowledge of RTS, S Malaria Vaccine

Figure 2 shows the awareness of the mothers when asked if they were aware of the development of the RTS,S/AS01 vaccine for the prevention of malaria in children. The majority (52%) of them were not aware there was a vaccine for malaria.

In addition, as shown in Table 3, those who were aware vaccine knew through several means such as through the radio, television, social media and healthcare workers. However, the majority of them knew through healthcare workers (23.8%).

Also, majority (85.1%) of the mothers do not know the number of doses required for full vaccination with the RTS/S malaria vaccine. The majority (69.6%) were also unsure about the availability of the vaccine in Nigeria.

Table 3: Sources of awareness and knowledge of RTS/S malaria vaccine in Lagos, Nigeria

Variable	n= 395 (%)
Source of awareness of RTS/S malaria vaccine
Radio/TV	48 (12.2)
Newspaper	10 (2.5)
Healthcare workers	94 (23.8)
Social media	37 (9.4)
Not applicable	206 (52.2)
Number of complete doses needed for RTS/S vaccine
Three	40 (10.1)
Four	9 (2.3)
Five	10 (2.5)
I don’t know	336 (85.1)
Is the vaccine in Nigeria?
Yes	97 (24.6)
No	23 (5.8)
I don’t know	275 (69.6)

Perception and Willingness to Accept RTS, S Malaria Vaccine

Table 4 below shows the results of the perception and willingness to accept RTS/S malaria vaccine by mothers of under-five children in Lagos, Nigeria.

More than two-thirds of the mothers (84.8%) were willing to receive the RTS/S malaria vaccine for their children. However, fewer than 60% of them strongly agreed/agreed that the vaccine is safe and cannot harm their children. Almost two-thirds of the mothers (64.3%) are willing to pay-out-of-pocket if the vaccine is not cost free. The majority of the mothers (88.9%) strongly agrees/agrees that the vaccine should be included in the routine immunization of children. Most of the mothers (85.3%) agreed that the vaccine would save money spent on the treatment of malaria. However, not up to two-third of the mothers (64.3%) strongly agreed/agreed that the vaccine would prevent their children from falling ill due to malaria. Finally, 84.9% of the mothers reported that the vaccine did not contradict their cultural beliefs.

Table 4: Perception and willingness to accept RTS/S malaria vaccine in Lagos, Nigeria

Perception and Willingness	Strongly agree/agree n= 395 (%)	Neutral n= 395 (%)	Strongly disagree/disagree n= 395 (%)
I am willing to accept the vaccine for my children	335 (84.8)	56 (14.2)	4 (1.0)
The vaccine should be included in the routine immunization of children	351 (88.9)	42 (10.6)	2 (0.6)
If the vaccine is not cost free, I am willing to pay out of pocket	254 (64.3)	95 (24.1)	46 (11.6)
The vaccine is safe and cannot harm my child	216 (54.7)	171 (43.3)	8 (2)
The vaccine can prevent my child from having malaria	254 (64.3)	131 (33.2)	10 (2.5)
Malaria vaccine will save money spent on treatment of malaria	337 (85.3)	51 (12.9)	7 (1.8)
The vaccine is not against my cultural belief	335 (84.9)	47 (11.9)	13 (3.3)

Predictors of Acceptance for RTS, S Malaria Vaccine

The results of the multivariate analysis (binary logistics regression) presented in Table 5 identified the factors that predicted the willingness of mothers to receive the RTS/S malaria vaccine for their child (ren). The result revealed that those who were undecided on the possibility of the vaccine to infect their children with malaria were nine (9) times more likely to accept the RTS/S malaria vaccine compared to those who are certain that the vaccine would not infect their children with malaria (OR = 9.075, 95% CI = 01.275 – 64.581, p =0.028). Moreover, participants who were aware of the RTS/S malaria vaccine (OR = 3.033, 95% CI = 1.366 –, 6.735, p <0.05) were three (3) times more likely to accept the vaccine compared to those who were not aware of the vaccine.

Finally, mothers who were not sure if the vaccine can truly prevent malaria are surprisingly two (2) times more likely to accept the vaccine (OR = 2.342, 95% CI = 1.035 – 17.636, p =0.045) compared to those who believe the vaccine can prevent malaria in their children.

Table 5: Predictors of acceptance of the RTS/S Malaria vaccine

Predictors	OR^a	95% CI^b	P value
The vaccine cannot infect my child with malaria
No	Ref
Yes	1.832	0.452 – 7.421	0.396
Unsure	9.075	1.275 – 64.581	0.028

Are you aware of the RTS/S malaria vaccine?
No	Ref
Yes	3.033	1.366 – 6.735	p <0.05
The vaccine can prevent my child from having malaria
No	Ref
Yes Unsure	0.000 2.342	1.035 – 17.636	0.999 0.045

^aOR: odds ratio

^bCI: confidence interval

In the last 10 years, substantial progress has been made in the development of malaria vaccines to treat this disease. Although, with moderate efficacy, the RTS, S/AS01 is the first ever- recommended vaccine by the WHO and European Medicines Agency (EMA) and can therefore be administered in malaria-endemic areas, especially Africa. (17)

Before a malaria vaccine intervention can be implemented in sub-Saharan Africa, plans must be made to increase awareness and educate the populace, especially mothers of children younger than 5 years old. To develop a successful malaria vaccine implementation programme in Lagos State, this study aimed to assess the knowledge, awareness and perceptions of mothers of under-five children in the Lagos West Senatorial District (Alimosho, Ikeja), Lagos Central Senatorial District (Surulere) and the Lagos East Senatorial District (Kosofe, Ikorodu), which are the 3 Senatorial Districts in Lagos state.

From the sociodemographic results, it can be deduced that a majority of the mothers are married (86.3%), have post-secondary education (71.3%) and are in their early twenties to late thirties. This could mean that a good number of Lagos mothers above 40 years of age do not attend healthcare facilities for the routine immunization of their children and might not have a basic understanding of routine immunizations, vaccine preventable diseases and ultimately novel malaria vaccines. A vast number of respondents are Yoruba or Igbo and are either self-employed, work in a private sector or civil servants. This socio-demographic result is similar to the one gotten from a study by Musa-Booth et al., 2020 (18).

The attitude of mothers toward vaccine-preventable diseases and routine immunization in this survey were satisfactory and in line with a study carried out by Gentle, 2019, where the results of his study indicated mothers had a positive attitude towards receiving routine immunizations (19). He went further to conclude that this attitude will go a long way in prompting good health and invariably overall wellbeing, a statement we concur with.

In this study, a vast majority (97.2%) of the mothers showed a positive attitude towards vaccinating their children against vaccine-preventable diseases with approximately 2.8% not providing a satisfactory response. This could be credited to the relentless effort of healthcare facilities at the primary and secondary level of care which continuously educates mothers about routine immunizations. A good number of these mothers (94.2%) are also up-to-date with their children’s routine vaccination compared to population (5.8%) who are not. Therefore, sending reminders to all mothers and following up with mothers who fail to show up for the immunization of their children at expected dates should be considered.

From this study, it was revealed that the major challenges faced by mothers in keeping up with these routine immunizations are (in decreasing order of severity); busy work schedules, lack of awareness about vaccination exercises and distance to vaccination centers as depicted in Fig. 1. In a study by Tefera et al., 2018, mothers who have full time jobs outside their home, face time constraints that negatively affected the possibility of completing routine immunizations for their children (20). It will therefore go a long way in involving fathers in vaccine education sessions so that they can encourage and sometimes fill in for the inadequacies or gaps of some mothers who have challenges such as busy work schedules, lack of awareness about vaccination exercise and distance to vaccination centers.

With the Lagos state government working effortlessly to ensure that primary healthcare centers (PHCs) are in every local council development area (LCDA), the challenge of distance to vaccination centres and lack of awareness about vaccination exercises should not stem (21). This is therefore to show that much publicity still needs to be done in ensuring that mothers aware of the availability of PHCs in their community and the variety of healthcare services that they offer, immunization included. A point to also note is to ensure that measures are put in place to ensure a continuous supply of vaccines at all immunization centres.

Although there was little disparity in the awareness of the RTS/S malaria vaccine, 52% of the mothers were not aware of the development of this vaccine as against the 48% who were. This result is different from the one obtained by Musa-Booth et al., in 2020 when studying the knowledge, attitude and willingness to accept the RTS, S malaria vaccine among mothers in Abuja Nigeria where a lower percentage of the population 30% (36 out of 180) were aware of the malaria vaccine, 5% (8/180) knew what a malaria vaccine was used for and 7 out of the 180 mothers had heard of RTS/S (18). The disparity between our results could be a factor of time as our findings shows that more mothers are now aware of the RTS,S malaria vaccine.

Over three (3) years, the dissemination of information about malaria vaccine and RTS/S could have increased. Although, there is still a long way to go in educating mothers about malaria vaccines, the knowledge about it has greatly improved. In addition, our findings showed that healthcare workers were the source of information for majority (23.8%) of those that had knowledge of the malaria vaccine. This underscores the importance of healthcare workers in the enlightenment of the public about major health programs and services (22). A key point to also note is that despite the awareness, a great deal of the respondents (85.1%) do not know the number of doses required for a full vaccination and 69.6% cannot answer to whether or not, the malaria vaccines are already in Nigeria. A ceaseless communication of important malaria messages has been seen to be effective in improving the awareness of malaria and the same is required to increase the knowledge of RTS/S when available for use in routine immunization (18).

This study also reveals that the majority of mothers (84.8%) are willing to accept the RTS/S malaria vaccine for their child (ren) despite not being certain about its safety and efficacy. A good number of them (64.3%) are even willing to go the extra mile in paying out-of-pocket for the vaccine if they do not come as free because of the cost-effectiveness in the long run. A great percentage (88.9%) also agreed that the malaria vaccine should be added to the routine vaccination. With all these positive responses, less than 60% of the respondents strongly agreed/agreed that the vaccine is safe and will not cause harm to their children. Also, 64.3% strongly agreed/agreed that the vaccine will prevent their children from falling ill due to malaria. This points to the need for educating mothers about the safety and efficacy of the novel malaria vaccine.

In this current study. predictors of RTS,S/AS01 malaria vaccine includes possibility of the vaccine to infect children with malaria, awareness about the vaccine and possibility of the vaccine to prevent malaria (Table 5). Mothers that are aware about the vaccine are more likely to accept the vaccine than those that are not. This means that stakeholders, especially the government should increase publicity about the vaccine which is due to be received by Nigeria in April 2024 (23). The COVID-19 vaccination was largely accepted in Nigeria due to the relentless efforts of the stakeholders to make information about it easily accessible (24, 25). The same strategy should be considered for the RTS,S/AS01 malaria vaccine.

Also, Table 5 shows that mothers that are unsure of the safety of the vaccine (i.e the possibility of the vaccine to infect children and its possibility to prevent malaria) are more likely to accept the vaccine for their children. This result is not surprising since malaria is endemic in Nigeria, claiming lives of many children (26). Mothers would still give the vaccine a try despite not being sure of its overall safety because of its obvious benefits that outweigh the risk. Yet, government and stakeholders should strive to eliminate the doubts that parents could have about the RTS/S malaria vaccine due to the real threat of vaccine hesitancy in Nigeria (27).

This study's methodology involved using a self-administered survey that relied on participants' knowledge, awareness, and perception attending selected immunization clinics throughout a given time frame. The acceptance of the RTS/S malaria vaccine was also tested in this study at a moment in time that may have changed as a result of Nigeria's vaccine rollout. Selection bias may have been induced by the study's design flaws, which also might have reduced the study's generalizability. To properly understand the RTS/S vaccination reluctance in Nigeria, future research is advised to use a mixed methodologies approach that combines qualitative and quantitative techniques. Subsequent investigations could provide additional understanding of the fluctuations in RTS/S vaccination reluctance over time and the variables linked to these shifts.

This study revealed that majority of women who attend clinics for vaccination in Lago state, Nigeria are educated with post-secondary school qualification and below the age of forty years. Majority of these women have satisfactory attitude towards immunization for vaccine preventable diseases and are up to date with the vaccination schedules of their children. Some of the challenges to vaccination shown by this study include busy schedules of mothers, lack of awareness and distance to the vaccination centers. A good number of the women are not aware of the RTS/S malaria vaccine which is expected to be initiated into the Nigeria vaccination program by April 2024 while many of them are willing to accept the vaccine and even pay out-of-pocket because of the long-term benefit of this vaccine on their children. The findings of this study revealed the need to create more awareness on this vaccine, encourage men to participate in vaccinating their child(ren) in cases where their mothers are not disposed, create more vaccination centers and assure the mothers of the safety profile of the malaria vaccine.

WHO- World Health Organization

PHCs- Primary Healthcare Centers

ITNs - Insecticide-treated nets

UNICEF- United Nations Children’s Fund

CSP- Circumsporozoite

EMA - European Medicines Agency

LCDA- Local Council Development Area

Ethics approval and consent to participate

The ethical clearance and approval for this study was obtained from the Lagos State University Teaching Hospital, Health Research and Ethics Committee with Reference Number LREC/06/10/2053. The participants (mothers) were informed of the objectives of the study and its potential benefits for the public health system in Nigeria. There were minimal risks to participants as no invasive procedure was involved. Verbal informed consents were obtained from each participant prior to enrollment in the study.

Consent for publication

Not applicable

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Competing interests

The authors declare that they have no competing interests

Funding

This work is self-funded. No external funding was received in part or whole towards its completion

Authors' contributions

Conceptualization, Q.A.O.; Data curation, Q.A.O., R.M.B., A.O.L., J.C.U; Formal analysis, Q.A.O.; Methodology, Q.A.O. and R.M.B.; Visualization, Q.A.O., R.M.B., A.O.L., J.C.U.; Writing—original draft, Q.A.O., R.M.B., A.O.L., J.C.U; Writing—review & editing, Q.A.O., A.O.L., and J.C.U

All authors have read and agreed to the published version of the manuscript.

Acknowledgements

The authors are grateful to the immunization clinic staff of the study sites for this project especially Lagos State University Teaching Hospital and Coker-Aguda Primary Health Centre

Breman, J. G., Alilio, M. S., & Mills, A Conquering the intolerable burden of malaria: what's new, what's needed: a summary. The American journal of tropical medicine and hygiene, . (2004) 71(2 Supp), 1-15.
Syed, Y. Y. RTS, S/AS01 malaria vaccine (Mosquirix®): A profile of its use. Drugs & Therapy Perspectives, (2022). 38(9), 373-381.
El-Moamly, A. A., & El-Sweify, M. A. Malaria vaccines: the 60-year journey of hope and final success—lessons learned and future prospects. Tropical Medicine and Health, (2023). 51(1), 29.
Laurens, M. B. RTS,S/AS01 vaccine (Mosquirix™): An overview. Human vaccines & immunotherapeutics, (2020) 16(3): 480–489. https://doi.org/10.1080/21645515.2019.1669415
AboulFotouh, K., Xu, H., Moon, C., Williams III, R. O., & Cui, Z. Development of (inhalable) dry powder formulations of AS01B-containing vaccines using thin-film freeze-drying. International Journal of Pharmaceutics, (2022). 622, 121825.
Fortpied, J., Collingnon, S., Renaud, F., Bayat, B., and Lemoine, D. The thermostability of the RTS,S/AS01 malaria vaccine can be increased by co-lyophilizing RTS,S and AS01. Malaria Journal (2022).
Lell, B., Agnandji, S., von Glasenapp, I., Haertle, S., Oyakhiromen, S., Issifou, S., et al. A Randomized Trial Assessing the Safety and Immunogenicity of AS01 and AS02 Adjuvanted RTS,S Malaria Vaccine Candidates in Children in Gabon. PLoS ONE, (2009). 4(10): e7611. https://doi.org/10.1371/journal.pone.0007611
World Health Organization. WHO Guidelines for Malaria, 18 February 2022. World Health Organization; 2022.
Omotayo A.I, Adeolu T.A., Adedayo O.O., Abiodun K.O., Aishat K. G., Adeniyi A, Samson T.A Community Knowledge, Attitude and Practices on Malaria Vector Control Strategies in Lagos State, South-West Nigeria. Journal of Medical Entomology, (2021) Vol. 58, No. 3 doi:10.1093/jme/tjaa278
Thu, A. M., Phyo, A. P., Landier, J., Parker, D. M., & Nosten, F. H. Combating multidrug‐resistant Plasmodium falciparum malaria. The FEBS journal, (2017). 284(16), 2569-2578
Nasir, U. N., Bandyopadhyay, A. S., Montagnani, F., Akite, J. E., Mungu, E. B., Uche, I. V., & Ismaila, A. M. Polio elimination in Nigeria: a review. Human vaccines & immunotherapeutics, (2016). 12(3), 658-663.
MacDonald, N. E. Vaccine hesitancy: definition, scope, and determinants. SAGE Working Group on Vaccine Hesitancy, Epub, (2015). 33(34):4161-4.
Dubé, E., Laberge, C., Guay, M., Bramadat, P., Roy, R., and Bettinger, J. Vaccine hesitancy: an overview. Human Vaccine Immunotherapy,; (2013). 9(8):1763-73.
World Health Organization Report of the SAGE Working Group on Vaccine Hesitancy. Geneva, Switz: World Health Organization. (2014). www.who.int.myaccess.library.utoronto.
Kuyinu YA, Femi-Adebayo TT, Adebayo BI, Abdurraheem-Salami I, Odusanya OO. Health literacy: Prevalence and determinants in Lagos State, Nigeria. PLoS One. (2020) Aug 13;15(8):e0237813. doi: 10.1371/journal.pone.0237813. PMID: 32790756; PMCID:PMC7425911.
Lemershow, S., D. W. Hosmar, J. Klair, and S. K. Lwanga Adequacy of sample size in health studies. WHO Ed, Wiley, (1990) Chichester, United Kingdom.
Nadeem, A., & Bilal, W. Acceptance, availability and feasibility of RTS, S/AS01 malaria vaccine: A review of literature. Asian Pacific Journal of Tropical Medicine, (2023). 16(4), 162-168.
Musa-Booth, T. O., Enobun, B. E., Agbomola, A. J., & Shiff, C. J. Knowledge, attitude and willingness to accept the RTS, S malaria vaccine among mothers in Abuja Nigeria. (2020). medRxiv, 2020-12.
Gentle, S Knowledge and Attitude of Mothers towards Immunization in Emohua Local Government Area of Rivers State. Int J Innov Healthc Res, . (2019). 7(4), 38-52.
Tefera, Y. A., Wagner, A. L., Mekonen, E. B., Carlson, B. F., & Boulton, M. L. Predictors and barriers to full vaccination among children in Ethiopia. Vaccines, (2018). 6(2), 22.
HEFAMAA. Lagos is restoring confidence in primary health care – Onanuga - HEFAMAA. HEFAMAA. (2016). https://hefamaa.lagosstate.gov.ng/lagos-restoring-confidence-primary-health-care-onanuga/
Frenk, J., Chen, L., Bhutta, Z. A., Cohen, J., Crisp, N., Evans, T., ... & Zurayk, H. Health professionals for a new century: transforming education to strengthen health systems in an interdependent world. (2010). The lancet, 376(9756), 1923-1958.
Are, J. FG: Malaria vaccine approved by WHO to be in Nigeria by 2024. TheCable. https://www.thecable.ng/fg-malaria-vaccine-approved-by-who-to-be-in-nigeria-by (2023).
Reuben, R. C., Danladi, M. M., Saleh, D. A., & Ejembi, P. E. Knowledge, attitudes and practices towards COVID-19: an epidemiological survey in North-Central Nigeria. Journal of community health, (2021). 46, 457-470.
Solís Arce, J. S., Warren, S. S., Meriggi, N. F., Scacco, A., McMurry, N., Voors, M., ... & Omer, S. B. (2021). COVID-19 vaccine acceptance and hesitancy in low-and middle-income countries. Nature medicine, (2021) 27(8), 1385-1394.
Abanyam NL. Malaria and Socio-Economic Development in Nigeria. Lead City Journal of the Social Sciences. 2020 Jun;5(1):81.
Sato R, Takasaki Y. Vaccine Hesitancy and refusal: behavioral evidence from rural Northern Nigeria. Vaccines. 2021 Sep 14;9(9):1023.

No competing interests reported.

Knowledge, Awareness and the Willingness to accept the RTS,S/AS01 malaria vaccine among mothers of under-five children in Lagos, Nigeria

Status:

Version 1

Abstract

Figures

Introduction

Methods

Study design

Study Setting

Sampling Procedure

Inclusion and exclusion criteria

Data Collection

Ethical Consideration

Statistical analysis

Results

Discussion

Conclusion

Abbreviations

Declarations

References

Additional Declarations

Status:

Version 1