Seroprevalence of poliovirus antibodies in Nigeria: refining strategies to sustain the eradication effort.

Introduction: in 2016, a switch from trivalent oral poliovirus vaccine (OPV) (containing serotypes 1,2,3) to bivalent OPV (types 1,3) was implemented globally. We assessed the seroprevalence of poliovirus antibody levels in selected Nigerian states, before and after the switch, documented poliovirus type2 outbreak responses conducted and ascertained factors associated with immunity gaps based on seroprevalence rates. Methods: we conducted a secondary analysis of stored serum samples from the 2018 Nigeria National HIV/AIDS Indicator and Impact Survey. Serum from 1,185 children aged 0-119 months residing in one southern and four northern states were tested for serotype-specific PV neutralizing antibodies; seropositivity was a reciprocal titer ≥8. We conducted regression analysis to determine sociodemographic risk factors associated with low seroprevalence using SAS 9.4. Results: children aged 24-119 months (pre-switch cohort) had seroprevalence against PV1, PV2, and PV3, of 97.3% (95% CI:96.4-98.2), 93.8% (95% CI:92.2-95.5), and 91.3% (95% CI:89.2-93.4), while children aged <24 months (post-switch) had seroprevalence of 86.0% (95% CI:81.2-90.8), 55.6% (95% CI: 47.7-63.4), and 77.2% (95% CI:71.0-83.4) respectively. Regression analysis showed age <24 months was associated with lower seroprevalence against all PV serotypes, (p<0.0001); females had lower seroprevalence against PV1 (p=0.0184) and PV2 (p=0.0354); northern states lower seroprevalence against PV1 (p=0.0039), while well-water source lower seroprevalence against PV3 (p=0.0288). Conclusion: this study showed high seroprevalence rates against PV 1, 2, and 3 in pre-switch children (aged 24-119 months). However, post-switch children (<24 months) had low immunity against PV2 despite outbreak responses. Strategies to increase routine immunization coverage and high-quality polio campaigns can increase immunity against polio virus.

Interpersonal and community influences affecting childhood vaccination decision-making among Nigerian caregivers: Perceptions among frontline workers in Nigeria.

Although routine immunization has contributed to a substantial reduction in mortality from vaccine-preventable diseases globally, vaccine-preventable diseases are attributable for 22% of childhood deaths in Nigeria. Individual and structural level factors that influence vaccination uptake in Nigeria have been well documented. However, there is limited information about the role of interpersonal and community level factors. Frontline workers play a crucial role in delivering life-saving vaccines in Nigeria, as they are tasked with ensuring that all children are vaccinated, within the health system as well as traveling to underserved areas, where health systems are not able to reach. This qualitative study conducted focus groups to examine frontline workers' perceptions of influences affecting caregivers' vaccine-related decision-making. Community- and facility-based frontline workers (n = 47) identified village and community chiefs, as well as religious leaders as influential within the context of immunization uptake because of their trusted role within communities. Male partners and husbands were identified as also holding an enormous level of influence over childhood vaccination, and the credibility of frontline workers influenced vaccination coverage. Immunization programs should target not only caregivers but also key influencers-such as interpersonal and community sources-to make progress in reaching vaccination coverage goals.

Experiences and Lessons From Polio Eradication Applied to Immunization in 10 Focus Countries of the Polio Endgame Strategic Plan.

Nine polio areas of expertise were applied to broader immunization and mother, newborn and child health goals in ten focus countries of the Polio Eradication Endgame Strategic Plan: policy & strategy development, planning, management and oversight (accountability framework), implementation & service delivery, monitoring, communications & community engagement, disease surveillance & data analysis, technical quality & capacity building, and partnerships. Although coverage improvements depend on multiple factors and increased coverage cannot be attributed to the use of polio assets alone, 6 out of the 10 focus countries improved coverage in three doses of diphtheria tetanus pertussis containing vaccine between 2013 and 2015. Government leadership, evidence-based programming, country-driven comprehensive operational annual plans, community partnership and strong accountability systems are critical for all programs and polio eradication has illustrated these can be leveraged to increase immunization coverage and equity and enhance global health security in the focus countries.

Legacy of Polio-Use of India's Social Mobilization Network for Strengthening of the Universal Immunization Program in India.

The Social Mobilization Network (SMNet) has been lauded as one of the most successsful community engagement strategies in public health for its role in polio elimination in India. The UNICEF-managed SMNet was created as a strategy to eradicate polio by engaging >7000 frontline social mobilizers to advocate for vaccination in some of the most underserved, marginalized, and at-risk communities in India. This network focused initially on generating demand for polio vaccination but later expanded its messaging to promote routine immunization and other health and sanitation interventions related to maternal and children's health. As an impact of the network's interventions, in collaboration with other eradication efforts, these high-risk pockets witnessed an increase in full routine immunization coverage. The experience of the SMNet offers lessons for health-system strengthening for social mobilization and promoting positive health behaviors for other priority health programs like the Universal Immunization Program.

Role of Social Mobilization (Network) in Polio Eradication in India.

In 2009, India contributed to over half the global cases of poliomyelitis. Many believed that India would be the last country to be polio free. India proved them wrong and was certified polio free in 2014. In January 2016, India celebrated 5 years of being polio free. One of the major reasons behind the interruption of polio transmission in the Polio endemic states of Uttar Pradesh and Bihar was the deployment of Social Mobilization Network (SMNet). A three tiered structure, the 7300 strong SMNet is now the gold standard in public health communication. It mobilizes communities by spearheading civil society participation; and works at district, block and community levels. The SMNet's social mobilization has evolved into an accelerated approach for achieving results with principles of mobilization at its core. The SMNet targets resistance to polio immunization through a multipronged approach by using local religious leaders, community influencers, interpersonal communication, counseling, mothers meetings, announcements from religious institutions and rallies. The success of the SMNet has been its ability to identify and convert resistant families into advocates for polio immunization. Deeply respected in the community, the SMNet mobilizers (98 percent of whom are women) are themselves models for gender empowerment. The SMNet model shows how mobilization techniques can be harnessed for short term and long term goals and can be replicated in other health programs to achieve the same results as were achieved for Polio.