The unmet needs tool was successful because the data generated helped identify and address problems peculiar to noncompliant communities and interventions such as sensitization and community dialogue meetings with noncompliant caregivers on the benefits of OPV and the reasons for “too many rounds” of OPV campaigns. Also, provision of free medical consultations and free discounted drugs, the engagement of religious leaders, traditional leaders, youth, and edutainment programs were directed to noncompliant communities based on the identified unmet needs of the caregivers. There was an increase in OPV uptake among caregivers and a reduction in the number of noncompliant households recorded in Kaduna state as a result of fulfilling their unmet needs. The unmet needs intervention was effective in changing the negative attitude of some parents on polio immunization programs, with a majority of 54% willing to support immunization in their communities in our study.
We found respondents from noncompliant communities during the period under review had a large knowledge gap on the polio immunization program in Kaduna state. A knowledge gap on immunization could be one of the major contributing factors to vaccine rejection for their children. Most caregivers interviewed wanted to know from program implementers why there are too many rounds of OPV campaigns (27%) and why there is the use of only OPV (22%) for a disease they rarely see and not antigens against malaria or measles instead that affects their children more often than polio. There were also some respondents who demanded to be educated on OPV safety (22%), its benefits (7%), the side effects of OPV (22%), and the risk of paralysis that could be associated with frequent use of the vaccine. The findings were in line with a similar study on assessment of reasons for OPV refusal in five northern states of Nigeria conducted in 2012 by Michael et al.  where the results showed that 59% of respondents had knowledge gap on polio immunization.
The complaint of too many rounds of OPV campaigns continued to affect the program since the number of rounds did not decrease over time; this made it difficult for parents to comprehend and, subsequently, raised suspicion on the use of OPV and resulted in low uptake among caregivers, especially in the northern region of Nigeria . Noncompliant communities incited their youths to threaten vaccination team members not to visit their communities again to immunize children. An innovative approach was applied to engage youths from these communities as part of the vaccination teams which helped to overcome threats to vaccination teams and address noncompliance .
Mobilization is one vital component of immunization that encourages caregivers to turn up for immunization services . We found out that most parents from the noncompliant communities have more faith in religious leaders and trust this group more than traditional leaders or qualified health workers to convince them to accept full immunization for their children. WHO Kaduna state supports the engagement of religious leaders, Mallams, Quranic teachers, health workers, and traditional leaders to convince parents on the importance of immunization. These groups are deployed to specific areas where such concerns were raised to address the unmet needs of the target group living in those areas on the need to willingly allow immunization for their children.
Furthermore, in response to the suggested added interventions that were preferred by caregivers, many of the caregivers requested free medical consultation and drugs. Thus, temporary health camps manned by health workers that provide free consultations and free or discounted drugs are provided to such communities to meet their unmet needs. Some respondents wanted to have insecticide-treated mosquito nets and antenatal care services provided alongside immunization services, whereas others requested power supply, portable water, food, good roads, and fertilizer among other things from the government. Similar findings were mentioned in the study conducted in northern Nigeria in 2014 on the reasons for refusal of OPV , where 33% of the respondents urged the government to address other unmet health and social needs of the populace.
Surprisingly, there were very few caregivers who requested other routine immunization (RI) antigens. Hence, there was a low demand for routine immunization (probably due to lack of adequate understanding of the importance of RI antigens) as was also observed by Wonodi et al.  among some of the respondents interviewed from eight states in Nigeria in 2012. The value of RI was underestimated by respondents in most instances. The study revealed low demand for RI antigens among some of the respondents in identifying and addressing barriers to immunization coverage.
Routine immunization is the bedrock of immunization. Stakeholders need to strive hard towards creating demand in the context of RI services to improve uptake of RI antigens. The effort in addressing challenges faced by immunization needs to be sustained to prevent vaccine-preventable diseases from causing outbreaks in high-risk communities .
Overall, there was a positive attitude change towards OPV programs among noncompliant caregivers in 2016 compared with 2013 when the unmet needs intervention was introduced in Kaduna state. Belief is difficult to change over time, which indicates why Kaduna state still has some pockets of noncompliant households. However, there was an improvement in the level of OPV uptake in the state (2015–2016) compared with 2 years earlier (2013–2014).
Lessons learnt from the use of the unmet needs questionnaire points to the need to create demand for a routine immunization program for good coverage of other antigens in addition to OPV. High demand for RI antigens will curb the incidence of vaccine-preventable diseases from noncompliant communities and further sustain the effort gained in the fight against poliomyelitis. Integration of other health interventions such as a malaria program and improving the primary healthcare delivery system by provision of essential drugs at no charge alongside immunization services will also go a long way in reducing the burden of most childhood vaccine-preventable diseases in high-risk communities in Kaduna state.
Furthermore, noncompliant communities in the state have informed us of the need for a holistic approach. Policy makers need to collaborate with other units in the healthcare service delivery system and also with other sectors, especially areas that affect the general wellbeing of the populace that has a direct or indirect bearing on health determinants. Factors affecting health determinants are the provision of portable water, power supply, and good infrastructure. The majority of respondents in our study felt they had been deprived of such amenities by the government and craved for these services before they can allow vaccination of their children.
A major limitation of the study is a failure to use the appropriate format of the recommended unmet needs template for capturing the correct data by some of the interviewers at the initial stage which led to 504 datasets being discarded as a result of low quality. Also, it is possible that other important reasons why caregivers decline OPV for their children were not captured on the unmet needs template. Therefore, it is possible that some vital information could be missing for addressing noncompliance as a whole in some remaining noncompliant high-risk areas in Kaduna state.