GIS & Data Analytics

Supporting Access to Immunization through Supplementary Immunization Activities

By Abubakar Shehu and Emerald Awa- Agwu

Supplementary Immunization Activities (SIAs) are one of the four strategies put forward by the Global Polio Eradication Initiative (GPEI) in 1988. In Nigeria, SIAs include Immunization Plus Days (IPDs), Outbreak Responses (OBRs) and other immunization outreaches conducted by the Nigerian government and its polio eradication partners. The aim of SIAs is to interrupt the transmission of the poliovirus by immunizing all children under five years of age with two doses of oral polio vaccine irrespective of their previous immunization status—unimmunized, partially covered or fully immunized.

A child receiving the Oral Polio Vaccine

A child receiving the Oral Polio Vaccine

SIAs are intended to complement Routine Immunization. However, in some areas, they represent the major strategy for catching unimmunized children and ensuring that they are vaccinated against polio and other vaccine-preventable diseases. Access to routine immunization services may be hindered for a variety of reasons including:

  • Challenges with cold chain equipment leading to vaccine damage and loss of potency, and eventually, unavailability of vaccines. Caregivers are often reluctant to return to health facilities where vaccines were unavailable. This results in missed opportunities to commence or complete the vaccination course.

  • Security challenges that make health facilities hard to reach by caregivers who bring children for immunization.

  • Access-related challenges such as caregivers having to travel long distances to the health facility or being unable to afford the cost of transportation

  • Wrong myths or perceptions about vaccinations such as loss of fertility as a result of vaccination.

SIAs take immunization services directly to children at their doorsteps, thereby bridging any gaps that may result from an inability to access vaccines at the health facilities. By achieving a vaccination coverage of at least 80% (that is, by vaccinating at least 80% of the targeted children with a potent vaccine), herd immunity can be achieved and the poliovirus can be deprived of the susceptible hosts which it needs to survive.

Through Supplementary Immunization Activities, children who were missed by routine immunization services can be reached with life-saving vaccines

Through Supplementary Immunization Activities, children who were missed by routine immunization services can be reached with life-saving vaccines

Prior to 2012, Nigeria had been conducting SIAs but was still recording cases of wild poliovirus (WPV). After a holistic examination of the immunization program, it was discovered that there was a huge disparity between the actual versus reported immunization coverage. Reports from independent monitoring and supervision groups showed that the actual vaccination coverage of the SIAs was much lower than the reported coverage. There were many missed settlements and an even larger number of missed children. It was discovered that some vaccination teams never visited the communities, instead, they would discard the vaccines and record false information in the tally sheets to account for the empty vials. Not only was this frustrating the polio eradication efforts, but it was also causing the health system huge losses as a result of the wasted vaccines.

It became imperative to develop a methodology to improve vaccination coverage and ensure that the vaccination teams visited all the target settlements during SIAs. This led to the development and deployment of the Vaccination Tracking System (VTS) in 2012.

VTS provides healthcare administrators and partners in the polio eradication space with daily insight into the activities of vaccination teams during SIAs by collecting passive tracks of the vaccination teams using Geographic Information Systems (GIS technology-enabled android phones and uploading them onto a dashboard for visualization. This provides stakeholders with near-live data about the geo-coverage of the vaccination campaign. The system also identifies missed settlements on a daily basis so that immediate action can be taken and the settlements can be included in the ongoing campaign. Another benefit of the VTS is that it increases the accountability of vaccination teams because the vaccinators know that they are under constant supervision. This greatly reduces the risk of data falsification.

The VTS dashboard provides decision-makers with near-real-time data about the progress of immunization campaigns and outreaches

The VTS dashboard provides decision-makers with near-real-time data about the progress of immunization campaigns and outreaches

So far, VTS has been used to track 82 supplementary immunization activities in 30 states of Nigeria. A significant proportion of these states have seen an exponential increase in the vaccination geo-coverage rates from the first campaign tracked to the last tracked campaign.

Increase in vaccination coverage rates

Increase in vaccination coverage rates

VTS makes sure that eligible children who, for any reason, are unable to receive their vaccinations through the routine immunization sessions at the health facilities, have a second chance to be protected against vaccine-preventable diseases like Polio and Meningitis.

Strengthening Routine Immunization using Lessons learned from Polio Emergency Support

By Joshua Ozugbakun & Emerald Awa-Agwu

In July 2016, after over two years of being polio-free, two wild poliovirus cases were discovered in Borno State, Nigeria. This launched fresh efforts to strengthen the four pillars of polio eradication including Routine Immunization (RI), Supplementary immunization activities (SIAs) (including national Immunization Plus Days (IPDs)), Surveillance and targeted mop-up campaigns.

A health worker vaccinates a child with the Oral Polio Vaccine

A health worker vaccinates a child with the Oral Polio Vaccine

Partners, both local and international, collaborated with the Nigerian government at state and national level, through various interventions and projects to increase the coverage and effectiveness of IPDs and mop-up campaigns in order to increase herd immunity and stop polio transmission, especially in high-risk states like Adamawa, Borno and Yobe states. These interventions were coordinated by the State Emergency Routine Immunization Coordination Centers (SERICCs). Each SERICC is led by individual state governments and help to improve information sharing, joint programming of public health emergency management activities (planning, implementation, monitoring, and evaluation) with partners. The National Emergency Routine Immunization Coordination Center (NERICC) is responsible for strategy development and oversees the activities of all the SERICCs. With this coordination mechanism in place, the menace of polio is being tackled collaboratively and Nigeria is well underway to being declared ‘Polio Free’, a major milestone in its vaccine-preventable disease management efforts.
A major takeaway for Nigerian polio eradication stakeholders after years of battling polio is the need for data collection, management and storage systems to be upgraded. As the need to halt poliovirus transmission increased, it became increasingly obvious that paper-based data management systems were incapable of providing decision makers with the reliable, actionable data which they needed for effective programming. eHealth Africa responded to this challenge by supporting states across Nigeria to develop comprehensive, digital maps using our expertise in Geographic Information Systems (GIS). The accuracy of these maps improves the microplanning process and guarantees a greater coverage of settlements during campaigns.

Our GIS technology has improved the quality of maps used for polio campaign planning

Our GIS technology has improved the quality of maps used for polio campaign planning

In addition, through our Vaccinator Tracking Systems (VTS) project, GIS-encoded Android phones are used to record and store passive tracks of vaccinators as they conduct their house-to-house visits; allowing decision-makers to have an accurate picture of the settlements that have been covered during IPDS and mop-up campaigns. This data can easily be accessed through dashboards for a more detailed analysis and breakdown of coverage information.


Supporting polio emergency response activities also highlighted the need for the Nigerian health system to move from an emphasis on SIAs and campaigns to strengthening the RI and disease surveillance systems. Sound routine immunization and disease surveillance systems are necessary to sustain the herd immunity built through polio campaigns.

In Kano state, the LoMIS Stock solution helps the State Primary Health Care Management Board to ensure that the vaccine supply chain is maintained. Health workers at the facility level use the LoMIS Stock application to send reports on a variety of vaccine stock indicators including vaccine utilization, vaccine potency, stock levels, wastage rates, and cold chain equipment status. Supervisors access the reports through the LoMIS Stock dashboard and are able to respond appropriately. This ensures that the RI system is maintained and that health facilities are never out of stock.

In the past, Acute Flaccid Paralysis (AFP) surveillance in health systems across Africa was passive. This meant that disease surveillance and notification officers (DSNOs) only reported or investigated suspected AFP cases that were presented at the health facility. According to the U.S Centers for Disease Control and Prevention (CDC)1, over 72% of polio cases are asymptomatic and as such, will not present at the health facility. In addition, DSNOs are unable to visit every single community to actively search for AFP cases due to logistics and security challenges. Relying on data from passive AFP surveillance causes programs to be designed based on data that excludes the asymptomatic polio cases. Auto-Visual AFP Detection and Reporting (AVADAR) reduces the burden on the DSNOs by enlisting members of the community to actively find AFP cases and report using a mobile application on a weekly basis; thus, providing accurate real-time surveillance data that can be used for program planning and implementation.

An often overlooked factor that promoted the transmission of the poliovirus was the rejection of the polio vaccine by mothers and households due to various myths and socio-cultural barriers. By engaging traditional and religious leaders as ambassadors of vaccination, more mothers and households are accepting the polio virus.

The central lesson in Nigeria’s journey so far towards polio eradication is the importance of collaboration and engagement at all levels including communities. eHealth Africa is proud to be supporting governments and health systems across Africa to respond to the polio emergency.

Fighting Cholera with the Power of Geospatial Mapping

By Ayodele Adeyemo & Hawa Kombian

The Cholera Threat

According to the World Health Organization (WHO), cholera (an infectious disease which causes acute watery diarrhea) remains a global threat to public health with an annual average of 82,000 deaths. In Nigeria, the cholera burden has been an average of 10,000 cases annually with over 70% of the cases coming from Bauchi, Yobe, and Zamfara states.

Following the review and recent publication of WHO guidelines on cholera control, the Nigeria Centre for Disease Control (NCDC) has begun the implementation of innovative approaches to tackle cholera via:

  • Strengthening disease surveillance for early detection and quick response through innovative use of technology and data.

  • Improving coordination for technical support, resource mobilization, and partnership.

  • Adopting a multi-sectoral approach to meet the 2030 cholera elimination by working with the environment and Water and Sanitary Hygiene sectors to ensure that communities have good water and sanitary facilities which will prevent further outbreaks

The Digital Health Advantage

What does an innovative model for cholera prevention and control look like?

In 1854, John Snow mapped out the cholera deaths during an outbreak and observed that they all occurred within short distances and were clustered around the Broad Street pump. He went ahead to carry out statistical tests to illustrate the connection between the source of water and the cholera cases.

In synergistic partnership, NCDC and eHealth Africa (eHA) used advanced geographic information systems (GIS) technologies to build on John Snow’s ideas of mapping. eHA uses data-driven solutions and tools to improve community health, with specific expertise in the design, development, validation, and deployment of predictive models for diseases like cholera.

GIS allow experts to explore different aspects of a geographical point. The identification of patterns can drive insights and enable health stakeholders to make informed decisions about how to best plan public health interventions. Due to computational and technological advancement, GIS has been used in public health for epidemiology, resource planning, and surveillance among others.  

NCDC and eHA were able to utilize GIS capabilities to enhance the data management within the NCDC National Incident Coordination Centre (ICC). The ICC serves as a the emergency operations center for coordinating disease outbreaks at the national level.


eHA’s GIS and Data Analytics team works with the NCDC to map cholera hotspots (areas where cholera persists) across Nigeria’s Local Government Areas (LGAs). At the start of the outbreak, hotspot analysis helps determine where to vaccinate and what quantity of vaccines are required per LGA. This exercise ensures the effectiveness of the oral cholera vaccine immunization campaigns which are rolled out to stop the spread of disease.

In planning, data from 2012-17 displays the spread of cholera outbreaks and also shows the relative risks of the various LGAs which have reported an outbreak during the five year period.

The Big Picture   Data Source: Nigeria Centre for Disease Control

The Big Picture Data Source: Nigeria Centre for Disease Control

Data Source: Nigeria Centre for Disease Control

Data Source: Nigeria Centre for Disease Control

We layered the 2018 outbreak data with the historical hotspot analysis to identify specific trends and possible overlaps. The result of the hotspot analysis identified 83 LGAs as hotspots, with 87% reporting at least one case with over 70% of the burden from Bauchi, Kano, and Zamfara states. The LGAs identified as hotspots have enabled the government to make informed decisions about where to request vaccines to ensure that the most vulnerable areas are supported.

Data Source: Nigeria Centre for Disease Control

Data Source: Nigeria Centre for Disease Control

We continue to collaborate with the NCDC to strengthen cholera surveillance in Nigeria. The partnership ensures that data management and analysis expertise contribute to faster response and informed decision making before, during and after outbreaks.

This work was done in collaboration with the following partners:

  • Yennan Sebastian- NCDC

  • Adesola Ogunleye - NCDC

  • Heloise Lucaccioni - UNICEF

  • Helen Adamu - UMB

  • Kobi Ampah- WHO Geneva