Strengthening immunization service delivery post Ebola virus disease (EVD) outbreak in Liberia 2015-2017

Strengthening immunization service delivery post Ebola virus disease (EVD) outbreak in Liberia 2015-2017

Adolphus Clarke¹, Nicholas Blidi¹, Joseph Yokie¹, Mary Momolu¹, Chukwuemeka Agbo^2,&, Roland Tuopileyi², Julius Monday Rude², Mohammed Seid², Yohannes Dereje², Zakari Wambai², Alex Gasasiraa², Laura Skrip³, Ngozi Kennedy⁴, Evans Lablah⁴, Joseph Chukwudi Okeibunor⁵, Mamoudou Harouna Djingarey⁵, Ambrose Talisuna⁵, Ali Ahmed Yahaya⁵, Soatiana Rajatonirina⁵, Ibrahima Socé Fall⁵

 

¹Ministry of Health, Monrovia, Liberia, ²World Health Organization Country Office, Monrovia, Liberia, ³National Public Health Institute, Monrovia, Liberia, ⁴UNICEF Country Office, Monrovia, Liberia, ⁵World Health Organization, Regional Office for Africa, Brazzaville, Congo

 

 

^&Corresponding author
Chukwuemeka Agbo, World Health Organization Country Office, National office, Monrovia, Liberia

 

 

 

 

When implemented under optimal conditions, immunization is one of the most successful and cost-effective health interventions against vaccine preventable diseases [1] saving an estimated 2-3 million lives annually around the world [1, 2]. Such success has been largely attributed to the launching of the expanded program on immunization (EPI) by the World Health Organization in 1974 with the aim to reduce morbidity and mortality associated with six major causes of death among children [1, 2]. Immunized children can lead to healthier and more productive lives [1, 3] and extending vaccination schemes to adolescents and adults can propagate these advantages through the life course [3, 4]. The global vaccine action plan 2011-2020 (GVAP) was designed with a vision for the decade of vaccines (DoV), to eradicate, eliminate or control serious, life-threatening or debilitating vaccine preventable diseases [4, 5]. Liberia has been committed to implementing universal immunization coverage through the GVAP to achieve the goal of a DoV. Despite a decade-long civil war that decimated health infrastructure, institutions and overall economy, the Ministry of Health (MOH) made steady efforts to revitalize the health system. The immunization program was strengthened with marked increases in coverage and immunity [6-8]. The 2014-2015 outbreak of Ebola virus disease (EVD) set back an already fragile health system that was recovering from the civil unrest. During the EVD outbreak, less than of 70% of health facilities were open and universally demand for health services was low due to fear and distrust in the health system. The Government of Liberia (GOL) declared a state of emergency to control the wide spreading EVD outbreak [9]. Subsequently, all planned routine immunization activities such as outreach, supplemental immunization activities (SIAs), the Human Papilloma Vaccine (HPV) demonstration project, and polio vaccination campaigns, among others, were paused [6-8]. These were in accordance to the guidance for immunization programs in the african region in the context of Ebola [10]. On the same note, the MOH could not implement and monitor the annual EPI work-plans, as all attention, including deployment of human resources were refocused to control the outbreak. Similarly, VPDs surveillance including specimen transportation by DHL was neglected at the height of the EVD outbreak. Thus, Penta-3 immunization coverage decreased by 26%, from 76% in 2013 to 50% in 2014 while ,easles containing vaccine (MCV) coverage declined from 74% in 2013 to 58% in 2014 [11]. Simultaneously, there was a significant drop in the Non-polio AFP rate (population under 15 years) from 2.9/ 100,000 in 2013 to 1.3 /100,000 in 2015 (IDSR Database), well below polio free certification levels. Guinea and Sierra Leone encountered similar decline in immunization service delivery [12, 13]. Due to disruptions of health service provision, approximately 20, 000 children were unvaccinated on a monthly basis during the EVD outbreak, contributing to about 1.5 million unvaccinated children over an 18-month period [12]. Post EVD, the Liberia investment plan for rebuilding resilient health systems 2015-2021 and the immunization recovery plan for Liberia were developed with the aim to restore the immunization service delivery and overall health system. The introduction and piloting of new vaccines, technologies and innovations to strengthen quality health service delivery were also integral to the investment plan [6-8]. This paper aims to describe Liberia immunization program performance following EVD outbreak in 2014-2015, summarizing program management, activities and new vaccines & technologies implemented to strengthen EPI program, highlighting challenges and suggest recommendations for improvement plans to consolidate on progress made.

 

 

We conducted a desk review to summarize key activities conducted to restore immunization service delivery based on the strategic goals of the GVAP 2011-2020 namely: vaccine coverage targets at country and district levels, polio eradication, measles and MNT elimination, introduction of new vaccines and technologies (Table 1).

 

Study setting: Liberia is a tropical country in West Africa with an estimated population of about 4.1 million people, annual growth rate of 2.1%, total land area of 111,370 km², and is bordered by Sierra Leone in the west, Cote d'Ivoire in the East, Guinea in the North and the Atlantic Ocean in the South. There are 15 counties (equivalent to WHO districts) and 91 health districts (sub-districts). It has 570 health facilities delivering EPI services across the 15 counties. The EPI manager leads the program with team leads for immunization, VPD surveillance, SIA, Logistics and cold chain. Child Survival Focal Person (CSFPs) at county and district levels manage the program at the levels and supervises the vaccinators at the health facilities.

 

Data sources: data sources included immunization program evaluation and joint appraisal reports, program audits, technical reports, weekly and monthly EPI and VPD surveillance bulletins, quarterly EPI review meeting reports, meeting minutes, scientific literature, and literature. We also sourced data from DHIS2 database, IDSR database, auto visual AFP detection and reporting (AVADAR) and ONA Servers. Surveillance data were collected using the open data kit (ODK) mobile data application.

 

Data analysis: data on programs and vaccine uptake were evaluated for the period of 2015-2017 to show the impact of post-EVD implementation of the Liberia investment plan and immunization recovery plan. Frequencies and percentages were calculated to describe trends in coverage over time and geographic location. Data analysis for the ISS checklist was automatically performed in the ONA servers or exported to Microsoft Excel for further analysis. ArcGIS was used to develop geospatial and temporal distribution of data, including proximity analysis. We triangulated administrative data, independent monitoring data, LQAS survey data and WUENIC to compare outcomes and inform further analysis.

 

 

Routine immunization

 

The development of immunization recovery plan post EVD in 2015, the revision and implementation of routine immunization micro plans based on principles of RED/REC and the implementation of urban immunization strategy in Montserrado County to reach urban slums and underserved population were the main activities to increase the access to the immunization services. As part of capacity building of the vaccinators, it was conducted Immunization in Practice (IIP) for vaccinators, refresher trainings, on-the-job training and mentorship for vaccination teams. The improvement of supply chain was done though the completion of the national vaccine store at Caldwell, Montserrado and two regional cold rooms in Grand Gedeh and Bong Counties. The optimization of the cold chain equipment and recruitment and training of 15 county supply chain officers were also part of the strategy. As part of the management of the program, besides development of the comprehensive multi year plan (cYMP) 2016-2020, the budget allocation was increased from $50, 000 USD in 2015 to $650, 000 USD in 2016. Capacity building for national teams was done through trainings and workshop. The country introduced electronic supervision tools such as electronic integrated supportive Supervision (ISS) and electronic surveillance (eSurv) checklists via open data kit (ODK) and WHO AFRO ONA servers and enhanced community involvement through advocacy meetings, social mobilization, deepened community engagement. In addition, technical Working Group Meetings, supportive Supervisions and quarterly EPI review meetings were conducted besides the development and dissemination of information products such Monthly EPI bulletins, VPD surveillance updates.

 

Polio eradication

 

The program working with GPEI partners developed the Brazzaville Initiative (B.I.) to re-invigorate polio eradication activities following EVD outbreak control. The B.I. followed a mid-term review of the GPEI strategic plan in mid-2015 recommending strengthening AFP surveillance and containment activities, improving the quality of immunization campaigns and building national capacity to respond to outbreaks. The national polio committee prepared and presented the annual national polio update for 2016 following the EVD outbreak control at the ARCC annual certification meeting in Malabo, Equatorial Guinea in 2017, which was accepted. It was re-established active case search for AFP and stool transport for laboratory confirmation in Abidjan via DHL, conducted 10 rounds of Polio national immunization days (NIDs) and one round of sub-NIDs between 2015 to 2017, evaluated with independent monitoring (IM) and LQAS. In addition, it was conducted OPV SWICTH and introduced IPV into routine immunization. GAP 1 a and b were completed in 2016.

 

Disease control programs

 

The country conducted a catch up Measles SIAs targeting children 6-59 months in May 2015 and strengthened measles surveillance within the integrated disease surveillance response (IDSR) strategy were the main activities described. For yellow fever, it was conducted analysis of low yellow fever EPI coverage in 3 counties: Grand Bassa, Rivercess, and Montserrado and developed improvement plans.

 

New vaccines and technologies

 

The country introduced new vaccines such Rota vaccine, IPV and HPV Demo Project. Mobile data collection tools and GIS technologies, namely open data kit (ODK), ONA and AVADAR GIS software was also introduced.

 

Outcome results

 

Routine immunization of Penta 3: there was a 34% increase in immunization coverage for Penta 3 from 52% in 2015 to 86% in 2017 (WUENIC 2017) (Figure 1). The trends for both administrative coverage and WUENIC follow similar pattern but there are discrepancies between coverage rates reported by both administrative and WUENIC reports. However, the absolute number of children 0-11 months vaccinated with Penta 3 in 2017 was 165, 972, a 11% increase in number of vaccinated children from 150, 231 in 2016 (DHIS2 database). Table 2 shows that at the national level, Penta 3 dropout rate in Liberia reduced approximately 3 fold from 15.3% in 2015 to 5.5% in 2017. In 2015, 80% of Counties had dropout rates above 10% compared to 20% of counties by 2017. In 2017, Grand Gedeh and River Gee Counties had negative dropout rates. However, Grand Kru, Lofa, Margibi Counties had dropout rates close to 10%, although this was lower than it had been for Grand Kru and Margibi in 2015. Grand Bassa and Bomi counties consistently had dropout rates above 10% for the period under review. Further analysis shows that Grand Cape Mount, Grand Gedeh, Grand Kru, Margibi, Montserrado, Nimba, River Gee, Rivercess and Sinoe counties had two-fold reduction in dropout rates from 2015 to 2017.

 

Polio eradication: there was a significant improvement in AFP surveillance indicators with a rebound of non-polio AFP rate (NPAFP) rate from 1.2 in 2015 to 3.7 in 2016. As of Epi Week 52, 2017, the NPAFP rate was 4.3. The stool adequacy rate also improved from 79% in 2016 to 82% as of Epi Week 52, 2017, meeting the global target of 80%. Furthermore, there was 2 fold increase in the number of OPV doses received among the AFP cases from 36% in 2015 to 61% in 2017. However, 20% (32/168) of the cases reported unknown number of OPV doses received. The LQAS survey results showed that a total of 10/15 (67%) of Lots were accepted in RD3 compared to 9/15 (60%) of Lots RD1 of Polio campaign in 2017. Only 0.1% Lot were rejected at < 80% in RD3 campaign compared to 33% in RD1 campaign 2017. However, Maryland, Margibi and Sinoe counties (Lots) were consistently rejected in the LQAS surveys conducted in 3 round of polio campaigns in 2017 (Table 3). IM assessment for Polio campaigns showed that 3/3 (100%) of the campaigns in 2017 and 2016, had estimated coverage above 95% (less than 5% of target children missed) compared 0% of the same indicator in 2015. In 2016, IM results of all four rounds in 2016 and 2017 showed that less than 5% of children were missed during the polio campaigns, converging with administrative data for the national level (Table 4).

 

Measles control: Figure 2 shows that MCV1 coverage improved by 23% from 64% in 2015 to 87% in 2017 based on WUENIC 2017 data. Furthermore, Table 5 also shows that in 2015, the post measles campaign coverage survey at the national level was 73.1% by vaccination card and verbal history while the coverage of 90.4% by verbal history alone. Only 3/15 (20%) counties had vaccination coverage above 90%. However, 11/15 (73%) of counties achieved coverage above 90% when evaluated by verbal history alone. The 3 most populated counties Lofa, Nimba, Montserrado, had coverages below 65% when assessed by vaccination card alone. A significant number of suspected measles cases were reported in Liberia in 2017. Of the reported cases, 17% (317/ 1818) were laboratory confirmed, 47% (858/ 1818) tested negative for measles. Of the 814 discarded measles cases, 40% (347/ 858) tested positive for rubella. The pie chart shows that 29% of confirmed measles cases during the review period received MCV1. A significant number (56%) of the reported cases had unknown vaccination status. As of Epi week 52, 2017, highly populated counties (Nimba, Bong and Montserrado) accounted for most measles outbreaks in the country. Nimba and Bong also share common borders with neighbouring countries such as Guinea and Cote d'Ivoire. Montserrado County accounts for 1/3 of the country population, with urban slums and population migration.

 

Yellow fever control: there was significant improvement in yellow fever vaccine (YF) coverage in 2017 which was 84%. The YF vaccine coverage for routine immunization was below target levels from 2010 up to 2016 (Figure 3). Disaggregated data by county shows that 60% (9/15) of counties met the national coverage target in 2017. Only 47% (7/15) met the national target in 2016 and 2017. Grand Cape Mount, Grand Gedeh, Maryland and River Gee counties consistently had lower coverage from 2015 to 2017.

 

 

Routine immunization: Liberia demonstrated a strong rebound of immunization services following the devastation caused by unprecedented EVD outbreak in 2014-2015. This can be attributed to the commitment and leadership of immunization program team and the MOH working closely with partners leading to, for instance, the 12 fold increase in immunization budget line, capacity building for health workers and enhanced community engagement. This is in line with key strategic objectives of the GVAP 2011-2020 [5]. However disaggregated administrative data showed that 4 counties had less than optimal performance at the sub-national level. This is similar to literature elsewhere [1, 14] where overall vaccination coverage levels for Penta 3 stagnated at 85% at national levels with varied performance at the sub-nationals. Studies have identified contributing factors to low vaccination coverage such as high transport costs, low income, gender inequality [14] and these can also apply to the Liberia context. Overall, there was a reduction in dropout rates 2015 to 2017 at national level using Penta 1 & 3 as indicators, with a dropout rate at national level below 10% and within WHO acceptable range. However, there was still sub-optimal performance at sub-national levels with some counties consistently having high dropout rates for the review period. Several counties, reducing dropout rates by 2 fold within 3 years, made good progress and can share best practices. Two counties had negative dropout rates in 2017 and further review of data may be required. These findings are similar to other literature on immunization dropout rates [15, 16] with predicators of dropout rates including marital status, religion, sex of child and income bracket of parents. Strategies to address this gap through defaulter tracking tools such as mobile devices; ledgers and home based records have been demonstrated to work in similar settings in Kenya and Ghana and can apply for Liberia [16]. Initiatives such as the urban immunization strategies in Montserrado County and other equity driven programs to reduce equity gap in the most poorly performing and underserved counties enhanced the system to reach the most vulnerable populations. These initiatives will need to be strengthened and sustained to ensure that gains made in these counties are maintained and surpassed. Although both administrative data and WUENIC estimates for Penta 3 showed similar pattern of improvement between 2013 and 2016, there are still differences in vaccination coverage estimates from both datasets. This suggests gaps in data quality for immunization monitoring system as it is expected that both coverage values should converge or at least the difference should be marginal [11]. Various factors contribute to persistent data quality issues including out-dated census data to estimate target population, incorrect numerator due to poor data collection and population migration. Other studies have also noted that misinformation by national governments to foreign donors and poor information generated at health facility levels contribute to poor data quality as they seek to gain rewards for improved immunization coverage [17]. Nevertheless, the convergence of both administrative data and WUENIC for MCV1 from 2012 up to 2016 differs from what is obtainable for Pent3 and OPV3. This suggests better quality of data for this antigen, bearing in mind that Penta3/OPV3 are given at 14 weeks while MCV1 is given at 9 months. Thus further evaluation maybe required to ascertain contextual factors that can enhance the quality of the overall immunization data system. Liberia has instituted various mechanisms to evaluate quality of immunization data such as external reviews, SARA, data quality audits and verification exercises with the aim improving the quality of immunization data [6]. The use of LQAS survey to evaluate quality of immunization has been applied to various settings as a way to strengthen the quality of routine immunization data [18] and can be applicable to immunization program in Liberia.

 

Polio eradication: polio eradication remains a primary goal for immunization program in Liberia in line with GPEI and GVAP. This is buttressed by the recent presentation and acceptance of annual polio certification update by members of NCC to the ARCC in Equatorial Guinea in June 2017, thus maintaining polio free status post EVD outbreak. Improved OPV coverage, high quality SIAs, strengthened AFP surveillance, containment and outbreak preparedness are central to achieve this goal [19]. The B.I. with the goal of restoring polio eradication activities post EVD outbreak significantly contributed to the progress made. There was improvement in the quality of polio campaigns conducted during the review period as demonstrated by administrative coverage and independent evaluation of the campaigns. The polio campaigns met administrative coverage at the national level and independent monitoring showed that the number of missed children during the campaigns steadily declined and plateaued at less than 5% in all 4 campaigns conducted in 2017. Studies have noted that high quality SIA with innovations are essential to sustain the progress towards polio eradication by improving less than five years immunization coverage [20, 21]. In order to improve the quality of the polio SIA, LQAS survey was introduced in 2017 as an additional tool to evaluate the quality of the polio campaigns and to identify pockets of communities that were missed. This was useful as the administrative and IM coverage data for the Polio SIAs started to converge by 2016/2017. These results are similar to experience reported in literature, for instance in Nigeria, LQAS was shown to be a valuable tool with statistical reliability for monitoring campaign quality and with ability to detect areas most in need of program intervention [22]. Furthermore, LQAS has the capacity to allow the GPEI to track trends in campaign quality over time in countries implementing SIAs, especially when the campaigns are synchronized with neighbouring countries [23]. There was improvement with OPV coverage during the review period similar to PENTA 3. This suggests increased population immunity against poliovirus essential for eradication activities especially with the 2 fold improvement in the percentage of AFP cases receiving 3 or more OPV doses.

 

Measles elimination initiative: Liberia is committed to measles elimination strategies in line with global goals and efforts put in place to achieve this objective have contributed to improve routine measles vaccination MCV1 coverage from a decline following the EVD outbreak. Both administrative data and WUENIC estimates showed that MCV1 coverage met national goal. Although there has been improvement with MCV1 coverage at national level, disaggregated data shows sub-optimal performance in some counties (sub national level). Furthermore, the global target for countries aiming against elimination is 95% coverage or more at national level and in all districts [24], which is well above the national target of 80%. This has led to recurrent outbreaks in some counties, especially the highly populated counties in the country. A study by MJ Ferrari et al [25], showed that measles outbreaks will still occur when measles coverage level that are below elimination targets of 95%, thus the aim is to align national targets with global elimination targets of 95% and above. Furthermore, Liberia currently implements only one dose of MCV and this may contribute to the high number reported measles cases as the population immunity may not be optimal to prevent the recurrent outbreaks. WHO recommends 2 doses of MCV as a standard for all national programs [25]. The immunization program is currently working with GAVI and partners to introduce the second dose of MCV into the vaccine schedule. Additionally, the high number of suspected and confirmed measles cases in the country can be attributed to strengthened disease surveillance systems. The structures developed during the EVD outbreak response contribute significantly to this phenomenon, especially through enhanced implementation of IDSR system. The IDSR data also showed, more cases were confirmed for rubella infection in 2017 thus it is expedient for the country to commence plans to introduce rubella containing vaccine and establish rubella sentinel surveillance systems.

 

New vaccines and technologies: new vaccine introduced include HPV demo project, Rota vaccine, IPV and Ebola vaccines with immense capacity to improve overall health of the population. This is in line with GVAP objective of closing the equity gap between developed and developing countries [22] with lifesaving vaccines. The Ebola vaccines in particular contributed to controlling two outbreaks in 2015 and 2016. It also contributed in providing data and information necessary for further improvement in the vaccine delivery systems and licencing. However, these newly introduced vaccines may put more pressure on the already stretch immunization service delivery system in terms of human capacity, supply chain and infrastructure. Thus, there need to be consorted efforts to strengthen the existing systems and continuously build capacity of the health workers. Furthermore, global shortage of some of the vaccines such as IPV and HPV can slow implementation at scale while the current formulation of Ebola vaccines require extreme temperatures for storage that the immunization program does not have the capacity to accommodate. A number of new technologies and vaccines were introduced into the Liberia health system following EVD outbreaks. AVADAR, eSurv, ISS, electronic LQAS were introduced into the EPI program and primary strategies were to ensure complete government ownership of the programs [23], adapt the technologies to suit the country context, strong partner coordination and robust monitoring and evaluation systems to drive learning by doing for sustainable scale-up. The electronic surveillance tools such as eSurv and ISS contributed to strengthen supportive supervision and mentorship for frontline health workers, including active case search for AFP and other VPDs. It can also enhance accountability systems for surveillance personnel routine surveillance sites visit based on prioritization.

 

 

Liberia has made remarkable progress in restoration of immunization service delivery following significant decline due to the devastating EVD outbreak in 2014-2015. There was improvement immunization coverage of all antigens and reduced dropout rates at the national level. Key drivers for this can be associated with implementation of the immunization program within the GVAP framework and guidelines. However, there are still gaps within the system that need to be addressed in order to ensure maximum benefits from the immunization program. Some of these gaps include sub-optimal performance of immunization coverage and high drop-out rates at the county levels. Additionally, the quality of data for immunization service delivery is not optimal as there are discrepancies between administrative data and WUENIC data. The MCV coverage is still below elimination targets with sub-optimal population immunity and yet the country only has one dose of MCV in the immunization program. Nevertheless, Liberia has demonstrated strong capacity to adopt new technologies and vaccines into the immunization program with capacity to improve the health system and quality of service delivery. The primary strategies for successful introduction were country ownership, adaptation to country context and implementation within existing health system structures.

 

 

The authors declare no competing interests.

 

 

Authors conceived idea, with support from WHO scrutinized and identified the most appropriate literature. Authors analysed, synthesized and wrote the first draft of the manuscript. WHO provided further insights. The authors read and approved the final version of the manuscript.

 

 

Special appreciation goes to World Health Organization Liberia country office and field staff, UNICEF, County health teams and district health teams across the whole country, EPI-service providers across the country, International and national implementing partners for health programs across the country, Political leadership at Ministry of health, in counties (office of superintendent, paramount chiefs, town chiefs) and Resource persons at national, subnational and community levels namely leaders of women groups, youth, places of worship, community health workers and traditional healers.

 

 

Table 1: indicator description and target of the polio eradication used in Liberia

Table 2: Penta 3 dropout rate (DOR) at national and sub-national levels from 2015 to 2017, Liberia

Table 3: showing LQAS survey results from RD1-RD4 Polio campaigns, 2017 by County, Liberia

Table 4: administrative coverage and Independent Monitoring (IM) results for Polio campaigns in 2016 and 2017, Liberia

Table 5: showing results of measles coverage survey 2015

Figure 1: trends of Penta 3 coverage from 2006 to 2017, Liberia

Figure 2: graph showing trends of MCV1 coverage 2006 to 2017

Figure 3: yellow fever vaccination coverage by year from 2008- 2017, Liberia (Data Source WUENIC 2017 and Admin (2017))

 

 

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