*3.2. Immunization Challenges and Predictors in Urban and Peri-Urban*

A study in four cities of India identified some issues such as no first-time registration for childhood vaccination in Uttarakhand and children not receiving an associated package of health services such as child weighing in Chhattisgarh [15]. Despite the positive outlook for childhood vaccination, other maternal and child health services, including treatment of the sick child, and postnatal care suffered due to the COVID-19 pandemic.

A population-based longitudinal study was conducted by Meckonnen and colleagues in Kersa [21]. Through face-to-face interviews, data was collected from caregivers of over 14,000 children. Harar city children had a 45% coverage rate for full vaccination, while conversely, other towns classified as semi-urban showed the lowest level of full vaccination coverage. Overall, 39% of children were found to be fully vaccinated. Being in a semi-urban residence, older maternal age, rural residence, maternal education, and unemployment were associated with not being vaccinated. Some of the barriers responsible for low routine immunization coverage in urban settings included poor defaulter tracking mechanisms for urban children, unfriendly immunization service delivery in urban public health facilities due to overstretched human resources, lack of effective strategies to reach the most vulnerable and marginalized urban communities with vaccines, and private service provider barriers, to name a few.

A community-based cross-sectional mixed-method study conducted in Toke Kutaye district, central Ethiopia, assessed vaccination timeliness and associated factors among children [22] and found an overall timeliness of childhood vaccination of only 23.9 percent among children aged 12 to 23 months, making other children who did not receive timely vaccines vulnerable. Urban residence, participation of pregnant women in conferences, and institutional delivery are among the independent predictors associated with the timeliness of childhood vaccination.

A descriptive cross-sectional survey of adolescent girls' parents conducted in two urban and two rural secondary schools in Lagos, Nigeria, documented parental acceptance of human papillomavirus vaccination for adolescent girls [23]. Urban residence among other factors such as tertiary level of education in the mother, skilled occupation of both parents, and knowledge of HPV were all positively associated with getting vaccinated with HPV vaccines.

Tadesse and colleagues explored associated factors related to second-dose measles vaccination among under-five children in urban areas of North Shewa Zone, Oromia, Ethiopia, using a community-based cross-sectional study [24]. The study found a low (42.5%) level of second-dose measles vaccination (MCV2) among children in urban areas of the study area. Some of the predictors of MCV2 uptake included maternal age, average time mothers had been waiting for vaccination at the health facility, awareness about vaccinepreventable diseases, awareness around recommended age for the last MCV vaccine in the series, and knowledge of the recommended number of MCV doses. A lack of information was the major reason for children not getting the MCV2 vaccination.

Findings from a study in Cavite, the Philippines, which assessed hesitancy towards vaccines among caregivers using in-depth interviews, documented that among the reasons for delay or refusal of childhood vaccinations, fear of side effects emerged as the most salient concern, exacerbated by previous negative experiences (including trauma) from a dengue vaccine controversy in 2017. Respondents also highlighted religious, cultural, and health system factors, including appointment scheduling and waiting times as predictors of childhood vaccination [25].

#### *3.3. Identified Pro-Equity Strategies*

Some strategies to ensure full vaccination during the pandemic were also highlighted in some of the papers reviewed. In one such paper, parents from multiple states in India chose to use private hospitals for child immunization due to the fear of themselves or their kids getting infected with the COVID-19 virus [15]. Some of the facilities in these cities considered shortening the waiting time for routine childhood vaccination service delivery, while others changed their vaccination timing schedule to reduce the spread of infection during the COVID-19 pandemic.

Meckonnen and colleagues conducted a phenomenological qualitative study to document strategies to revitalize immunization service provision in urban settings of the cities of Addis Ababa, Dire Dawa, and Mekele in Ethiopia [26]. Their study found that the immunization service provision strategies existing during the study period in urban settings were not adequate to reach all children and are mostly static (fixed) sessions. Some of the proposed strategies included expanding routine immunization service access to marginalized populations through outreach services, strengthening the public–private partnership, engaging the private health facilities for vaccination services, and integrating technological innovations (such as digitalization of the EPI program and application of mHealth reminders) to facilitate inter-facility linkage.

Balogun and colleagues conducted a pre- and post-interventional study in seven urban slum communities in Ibadan, Nigeria, in 2020–2021 to document the effect of intensive training in improving older women's knowledge and support for infant vaccination in Nigerian urban slums [27]. Identified older women received training through participatory learning methods over an 8-month period with a manual and short video on the importance of immunization timeliness and completion, how vaccines work, and how to be advocates

and supporters of infant vaccination. It was shown that participatory learning improved the knowledge of these older women who provide support and supervision for childcare in urban slums about vaccination and how to better support infant vaccination.

The study from Oromia (Tadesse et al.) also recommended some strategies for increasing the uptake of MCV2, including shortening the waiting time for vaccination at the health facility to within half an hour, intensifying awareness for parents and caregivers, and paying particular attention to mothers who are older than 36 years of age [24].

#### **4. Discussion**

With the rapid globalization seen in many countries, it is imperative to proactively identify and address urban-specific challenges to routine immunization, including mapping and reaching zero-dose children and missed communities. This renewed focus will assist efforts toward extending the reach of vaccines in urban settings and contribute to achieving the IA2030 targets. Already, it is estimated that about 30% of zero-dose children live in urban and peri-urban areas [8], and these numbers could grow rapidly without sufficient focus and proactive interventions. A key step, which this paper has taken, is to review evidence on the backsliding of coverage and routine immunization performance in urban settings and select focus countries harboring more than 75% of zero-dose children globally, documenting predictors of coverage and pro-equity strategies. Findings from this review show evidence of backsliding and disruption across the globe in urban and peri-urban contexts; major urbanized countries from around the world, such as Brazil, Pakistan, Ethiopia, India, and Cameroon, show various levels of immunization performance disruption in multiple urban contexts [6,15,18,19,28]. The disruptions to immunization affected multiple vaccines in each country's routine immunization schedule, including BCG, yellow fever (YFV), and DPT. Many challenges varied across the different global contexts, including no first-time immunization registration for children, poor tracking mechanisms for urban children, unfriendly delivery, and lack of effective urban-immunization-specific strategies; similarly, varied determinants of higher immunization coverage included institutional delivery of children, higher maternal education, lower maternal age, and positive knowledge and attitudes around immunization. Of the identified pro-equity strategies, shortening waiting time for service delivery, improved outreach services, and promotion of maternal and female figure education were associated with higher levels of immunization coverage. The predictors of childhood vaccination in urban settings, as well as noted pro-equity strategies, as documented in these studies, are consistent with what has been documented pre-pandemic [29–31].

These results suggest several potential areas for effective interventions to accelerate inroads into urban immunization. The identified pro-equity strategies above link to challenges on immunization and higher immunization coverage levels, and while there is a lot of diversity in backsliding issues, successful pro-equity strategies were also tailored to specific contexts, which emphasizes the need to contextualize interventions to address specific idiosyncrasies in each context [32]. Some results were contradictory to the idea that urbanized populations can be associated with poorer vaccination coverage, but most of the studies supported this idea. Additionally, this is not surprising as the world population transitions to become more urbanized [12], especially with the limited studies focusing on the peculiarities of essential vaccination in urban and peri-urban contexts.

This review contributes to a clearer understanding of the post-pandemic landscape of urban immunization in low- and middle-income countries, including challenges, immunization coverage determinants, and most importantly, pro-equity strategies. These pro-equity strategies are essential to ensuring that vaccines reach under-served populations and missed communities, and in examining these strategies more closely, we can better generate a starting point for a roadmap to longer-term urban immunization information. These are consistent with earlier documentation of pro-equity strategies in Gavi-supported countries [33].

Contextualized pro-equity urban immunization interventions will result in faster advances toward the IA2030 targets, and work to halt and slow down current backsliding and fragility in immunization systems. Additionally, many of the results point to the room for multisectoral and integrated interventions, as many of the determinants related to low immunization coverage point to potential interventions on gender barriers, education barriers, and systems strengthening [32,34,35]. Tools such as the urban immunization toolkit are being used by several countries to complement existing immunization guidelines by tailoring immunization planning, implementing, and monitoring approaches to meet challenging contexts in urban areas, especially in slum environments; many such tools are available to support these efforts globally [35].

There are some limitations to the data reviewed, including its quantity, generalizability, and whether urban-specific immunization challenges and contexts can be differentiated from generalized immunization challenges and contexts. There were a limited number of studies examining the post-pandemic urban immunization landscape, and the evidence was limited to a relatively small number of countries. Studies that concentrated on the slums were included alongside other peri-urban and urban settings across many different countries, and due to the evidence being contextualized, it may not be possible to generalize these findings. Additionally, many of the studies reviewed were only conducted in urban settings, so evidence of uniquely urban-related challenges is somewhat limited, as these challenges could apply in other settings. Furthermore, the definitions of urban and periurban used across the studies may have varied, which could have affected the findings and interpretation.

Because there is a relative dearth of information about urban immunization occurring after the acute phase of COVID-19, and much more information about the acceleration of global immunization and backsliding, it is essential that more studies be conducted on this intersection, as it is crucial to have more disaggregated data around urban backsliding, immunization performance evidence, and pro-equity strategies. Issues specific to the urban context need to be differentiated from generalized data in order to contextualize and prioritize the necessary correlated interventions and pro-equity strategies.

#### *4.1. Policy Suggestions*


great promise [8,37]. More enhanced disaggregation of immunization data by urban in routine data systems, such as the WHO and UNICEF joint reporting form (JRF), as well as in coverage surveys will support monitoring and tracking of immunization services in urban areas.

The above and other context-specific policy adjustments should be considered to make improvements and tend toward achieving the IA2030 goals.
