Assessment of the 5C model for predicting prenatal intention and postnatal vaccination behavior is a novel contribution to the body of knowledge for addressing vaccination demand in Nigeria. The primary goal was adapting and validating the 5C scale using two independent measurement points from the same subjects (pre-post), where T1 assessed the vaccination intention of pregnant women (prenatal), and T2 considered actual behavior and decision months after childbirth (postnatal). Adapting the scale to predict vaccination intention and behavior in Nigeria was novel and revealing.
Reliability analyses for the 5C based on the original model and sequel upon examination were incompatible in the Nigerian setting. The internal consistency indicators were too low for all five indicators as compared to reliability indicators obtained in Western samples. This shows that the items did not fit well with their intended constructs in Nigeria as compared to the Western samples. Therefore, the assumption that the 5C scale or factors that predict vaccine hesitancy was wholly adaptable and valid in Nigeria was undetermined by this study. Nevertheless, items from the scale predicted behavior (more than intention) and additions to the scale proved useful in the Nigerian context.
Higher confidence as assessed after birth was related to better vaccine uptake. The measurement of the psychological antecedent of confidence seems to be the strongest predictor of the 5C scale, especially the item that measures confidence in the public authority/health system. The study shows that participants’ confidence in the country’s healthcare system is related with a more positive intention to vaccinate their child in the future. It may be assumed that the less mothers interact with and are exposed to vaccination knowledge from healthcare providers, healthcare workers, or public institutions managing vaccination, the lower their intention to vaccinate children, and vice versa. Confidence among mothers correlates with the assurance that vaccinating their unborn children would be very low in situations of a lack of trust in the healthcare workers and systems managing vaccination decisions in the country. This evidence could explain the slow, stagnant and/or declining childhood vaccination rates, which peaked at 31% in 2018 against the 90% target and the continued high rate of neonatal, under-five and infant mortality in Nigeria [11, 13]. Generally, there is declining confidence in Nigeria’s public authority/health system, especially for immunization, family planning, antenatal care, etc. [11, 13, 14]. This lays credence to why Nigeria remains the country with both the highest under- and unvaccinated children in the world in 2018 [43–46].
The confidence-eroding factor in the public authority or health system here could also be linked to misconceptions about the preventive role of immunization in Nigeria, especially where uptake rates are very low. The study found that some healthcare workers and health system managers exaggerate about immunization to motivate uptake, thereby giving caregivers the false impression that immunization prevents all childhood diseases [47.48]. Hence, the inability or failure of immunization to prevent all diseases erodes trust and confidence in the public institutions managing immunization and eventually the loss of faith in immunization as an intervention to give protection .
Also, the source of information and communication is critical to the perception developed by people toward vaccination. Based on this study, mothers who received their vaccination information through the antenatal care services/healthcare workers and doctors are confident about vaccine efficacy, are more likely to have a positive attitude toward vaccination and have a higher intention to vaccinate their children. Therefore, more should be done to link antenatal care services to all primary healthcare facilities in communities to enhance the knowledge required for healthy and safe childbirth, thereby increasing vaccination demand.
Another important finding was the role of religion. Religion significantly influences decision-making in many parts of SSA. Studies including the Pew survey found religion to be central to discourse about behavior and decision-making in SSA [49–52]. The confirmation of religion as a determinant of childhood vaccination intention among mothers was therefore not surprising. The variation among religious groups is even more affirmative, where Muslim mothers have a lower motivation toward vaccination than Christians. This behavior paralleled other studies that have examined the back-end impacts of religion or religious belief on vaccine uptake, either in SSA or Nigeria . It permeates individual, group and national decision-making, and the immunization system is no exception. Several decisions are filtered or measured from the lenses and understanding of religious standpoints.
Regions with strong Islamic influence have lower immunization coverage and high vaccine hesitancy, adding to other variables such as low literacy levels [54–56]. The Muslim-dominated northern region, for example, has the highest vaccine hesitancy level, demonstrated by being the region with lowest immunization coverage: the least being North-West at 8% and the highest being North-Central at 26% [13, 47]. Hence, a religiously biased targeted intervention approach is required. Since trust in vaccination information from antenatal care was highest, Nigeria’s immunization stakeholders should integrate “religious talk on vaccine acceptance” into their activities. Also, enlisting the support of influential Muslim women organizations such as the Federation of Muslim Women Association of Nigeria (FOMWAN) could be strategic.
The influence of masculinity on vaccination intention and behavior is striking. Several communities in the SSA are still situated intrinsically in the conservative low-income countries, where a strong patriarchal culture subsists . Therefore, the child’s father or husband’s opinion is crucial in overall household decision-making. In this study, the husband’s or father’s knowledge and attitude and/or belief shaped the household’s decision to vaccinate a child or not. The study shows that, when a husband’s or child’s father encourages or approves immunization for the child, a positive relationship to vaccination intention and behavior was observed. That is, children who are likely to complete full childhood immunization are those whose fathers possess a good vaccination disposition. Similarly, a child is less likely to begin or complete a full dosage of routine childhood immunization if the father’s attitude toward immunization is low. Another dimension for interpreting the study findings is that children of women who lack decision-making autonomy are less likely to complete childhood immunization [58, 59].
The data collection at T2 was critical to understand what predicts actual vaccination behavior (vaccination decision 12 months after childbirth). As observed in the analyses, vaccination intention was not meaningfully related actual behavior. However, vaccination was related to three of the 5C: when confidence in the vaccine effectiveness was high (Confidence), when mothers felt responsible for collective well-being (Collective responsibility), and when mothers indicated lower levels of everyday stress (Constraint). Likewise, additional variables (5C+) played an additional role in vaccination behavior. Mothers of infants were more likely to vaccinate their children when vaccination was supported by the mothers’ religious beliefs (Religion). Rumor and/or misinformation was a very powerful influencing factor among all four predictors of vaccination behavior. That is, misinformation or rumor about vaccination affect these four determinants and thus indirectly affect vaccination behavior. Rumor and/or misinformation about vaccination should therefore be addressed with effective rebuttal strategies [60, 61].
Constraints such as stress arising from the mother’s competing priorities that displaces vaccination or contributed to miss appointments must be isolated and addressed. Facilitating or incentivizing vaccination visits could be an option. Increasing the resources (human and logistics) for home visits will allay the barriers that make vaccination very stressful for mothers.
Also, since the study revealed that mothers who possess higher education were related to stronger beliefs in vaccination effectiveness and collective responsibility, mothers of infants with lower education should be a target group for vaccination literacy campaigns.
The study had some limitations that may or not have affected the outcomes. Based on observations during the fieldwork, the 5C scale did not produce the desired effect for a few reasons. Its constructs and coinage of the items are a bit too broad for the Nigerian cultural setting. Also, participants with low literacy (i.e., mothers with no or little education) struggled to fully understand the English grammar of some of the 5C items. Therefore, the 5C scale in the future needs to be rewritten in simpler and loose English grammar. Also, assessing and including pregnant women in the study takes a lot of logistics, despite targeting antenatal meetings.