Effectiveness of poliovirus vaccines against circulating vaccine-derived type 2 poliomyelitis in Nigeria between 2017 and 2022: a case-control study.

Background: Between 2018 and 2022, Nigeria experienced continuous transmission of circulating vaccine-derived type 2 poliovirus (cVDPV2), with 526 cases of cVDPV2 poliomyelitis detected in total and approximately 180 million doses of monovalent type 2 oral poliovirus vaccine (mOPV2) and 450 million doses of novel type 2 oral poliovirus vaccine (nOPV2) delivered in outbreak response campaigns. Inactivated poliovirus vaccine (IPV) was introduced into routine immunisation in 2015, with a second dose added in 2021. We aimed to estimate the effectiveness of nOPV2 against cVDPV2 paralysis and compare nOPV2 effectiveness with that of mOPV2 and IPV.

Update on Wild Poliovirus Type 1 Outbreak - Southeastern Africa, 2021-2022.

Since the Global Polio Eradication Initiative (GPEI) began in 1988, the number of wild poliovirus (WPV) cases has declined by >99.99%. Five of the six World Health Organization (WHO) regions have been certified free of indigenous WPV, and WPV serotypes 2 and 3 have been declared eradicated globally (1).

Polio eradication in a chronic conflict setting lessons from the Republic of South Sudan, 2010-2020.

Introduction: in 1988 the World Health Assembly set an ambitious target to eradicate Wild Polio Virus (WPV) by 2000, following the successful eradication of the smallpox virus in 1980. South Sudan and the entire African region were certified WPV free on August 25, 2020. South Sudan has maintained its WPV free status since 2010, and this paper reviewed the country's progress, outlined lessons learned, and describes the remaining challenges in polio eradication.

Real-time monitoring of a circulating vaccine-derived poliovirus outbreak immunization campaign using digital health technologies in South Sudan.

Introduction: the use of digital health technologies and geographical information systems (GIS) in the conduct of immunization campaigns had proven to be a success story, and is gaining acceptance towards improving supervision, accountability, and real-time access to quality information. The demand for real-time information by policymakers and stakeholders in the polio eradication programme is increasing towards ensuring a world free from all polioviruses. This study aims to develop a tool that monitor and evaluate the circulating vaccine-derived poliovirus (cVDPV) campaign processes in real-time using open data kits (ODK) to collect data, analyze and visualize using an interactive dashboard in Power BI, towards improving timeliness and completeness of data reporting and providing real-time quality information to stakeholders.

A Survey to Assess Serological Prevalence of Poliovirus Antibodies in Areas With High-Risk for Vaccine-Derived Poliovirus Transmission in Chad.

Background: World Health Organization African region is wild poliovirus-free; however, outbreaks of vaccine-derived poliovirus type 2 (VDPV2) continue to expand across the continent including in Chad. We conducted a serological survey of polio antibodies in polio high-risk areas of Chad to assess population immunity against poliovirus and estimate the risk of future outbreaks.

Methods: This was a community-based, cross-sectional survey carried out in September 2019.

Risk factors for the spread of vaccine-derived type 2 polioviruses after global withdrawal of trivalent oral poliovirus vaccine and the effects of outbreak responses with monovalent vaccine: a retrospective analysis of surveillance data for 51 countries in Africa.

Background: Expanding outbreaks of circulating vaccine-derived type 2 poliovirus (cVDPV2) across Africa after the global withdrawal of trivalent oral poliovirus vaccine (OPV) in 2016 are delaying global polio eradication. We aimed to assess the effect of outbreak response campaigns with monovalent type 2 OPV (mOPV2) and the addition of inactivated poliovirus vaccine (IPV) to routine immunisation.

Methods: We used vaccination history data from children under 5 years old with non-polio acute flaccid paralysis from a routine surveillance database (the Polio Information System) and setting-specific OPV immunogenicity data from the literature to estimate OPV-induced and IPV-induced population immunity against type 2 poliomyelitis between Jan 1, 2015, and June 30, 2020, for 51 countries in Africa.

Real-time prediction model of cVDPV2 outbreaks to aid outbreak response vaccination strategies.

Background: Circulating vaccine-derived poliovirus outbreaks are spreading more widely than anticipated, which has generated a crisis for the global polio eradication initiative. Effectively responding with vaccination activities requires a rapid risk assessment. This assessment is made difficult by the low case-to-infection ratio of type 2 poliovirus, variable transmissibility, changing population immunity, surveillance delays, and limited vaccine supply from the global stockpile.

Surveillance Review System to Track Progress Towards Polio Eradication in the Horn of Africa.

Background: The risk for importation and reintroduction wild poliovirus in areas that have been cleared of the wild poliovirus in the Horn of Africa will remain if the surveillance systems are weak and porous.

Methods: Consequently, the Horn of Africa Polio Coordinating Office in Nairobi, together with partners conducted surveillance reviews for some of the countries in the Horn of Africa, especially Ethiopia, Kenya and Somalia to identify gaps in the polio surveillance and provided recommendations for improved surveillance. Structured questionnaires collected information about acute flaccid paralysis (AFP) surveillance resources, training, data monitoring, and supervision at provincial, district, and health facility levels.

Auto Visual AFP Detection and Response (AVADAR) Improved Polio Surveillance in Lake Chad Polio Outbreak Priority Districts.

The Auto Visual AFP Detection and Response (AVADAR) is a community-based digital platform that deals with the collection and distribution of real-time information. AVADAR makes it possible to report suspected cases of paralysis in the field at the central level. Once a suspected Acute Flaccid Paralysis (AFP) case is detected, a series of reports are sent to the following stakeholders: the nearest training officer, the district focal point, the district AVADAR team, the regional focal point, the central level of the Ministry of Health (MoH) and World Health Organization Country Office (WCO) by SMS and email.

Lessons Learnt from Interregional and Interagency Collaboration in Polio Outbreak Response in the Horn of Africa.

Following the outbreak of poliovirus in the countries in the Horn of Africa, Somalia, Kenya and Ethiopia, in two WHO regions, an outbreak response involving the WHO Africa and WHO East and Mediterranean Regions and partner agencies like the UNICEF in East and Southern African was developed. This paper documents response to polio virus outbreak in the Horn of Africa and the lessons learnt for the interregional and inter-agency collaboration on the response. This collaboration led to speedy interruption of the outbreak and within a period of one year the total virus load of 217 in 2013 was brought down to mere six.

Strategies to Reach Nomadic Children During Polio SIAs: Experience in Dadaab and Fafi Sub-Counties of Kenya after the 2013-2014 Polio Outbreak.

Background: Poliomyelitis, often called polio is a viral paralytic disease caused by Polioviruses. Although all susceptible individuals are at risk of getting infected, only about 1% become paralyzed. During the 2013 Polio Outbreak in Garissa County in Kenya, 50% of the confirmed cases were from the nomadic population although it comprises of only less than 20% of the total population in the county.

Simulation Exercises To Strengthen Polio Outbreak Preparedness in The Horn of Africa: Experiences and Lessons Learnt.

Background: Poliovirus importations and related outbreaks occurred in the Horn of Africa (HoA) following an initial outbreak, which started in Somalia, spread into Kenya within ten days and later into Ethiopia and gradually to other countries in the region. National preparedness plans for responding to poliovirus introduction were insufficient in many countries of the Region. We describe a series of polio outbreak simulation exercises that were implemented to formally test polio outbreak preparedness plans in the HoA countries, as a step to interrupting further transmission.

Polio Outbreak Investigation and Response in The Horn of Africa: 2013-2016.

Background: There has been civil strife, spanning more than two decades in some countries and recurrent natural disasters in the Horn of Africa (HoA). This has consistently maintained these countries in chronic humanitarian conditions. More important however is the fact that these crises have also denied populations of these countries access to access to lifesaving health services.

Effectiveness of the Horn of Africa Polio Outbreak Coordination Office in Nairobi, Kenya.

Background: The WPV1, first detected in Somalia in April 2013, quickly spread to Kenya and Ethiopia and triggered a multi-country coordinated effort. In February 2014, a formal HoA Polio Outbreak Coordination Office was established by WHO AFRO and WHO EMRO in Nairobi to provide technical and managerial leadership. An independent assessment was conducted to ascertain the usefulness of the HoA Coordination in response to the outbreaks.

The epidemiology of chronic kidney disease (CKD) in rural East Africa: A population-based study.

Background: Chronic kidney disease (CKD) may be common among individuals living in sub-Saharan Africa due to the confluence of CKD risk factors and genetic predisposition.

Methods: We ascertained the prevalence of CKD and its risk factors among a sample of 3,686 participants of a population-based HIV trial in rural Uganda and Kenya. Prevalent CKD was defined as a serum creatinine-based estimated glomerular filtration rate <60 mL/min/1.

HIV Testing and Treatment with the Use of a Community Health Approach in Rural Africa.

Background: Universal antiretroviral therapy (ART) with annual population testing and a multidisease, patient-centered strategy could reduce new human immunodeficiency virus (HIV) infections and improve community health.

Methods: We randomly assigned 32 rural communities in Uganda and Kenya to baseline HIV and multidisease testing and national guideline-restricted ART (control group) or to baseline testing plus annual testing, eligibility for universal ART, and patient-centered care (intervention group). The primary end point was the cumulative incidence of HIV infection at 3 years.

Forewarning of poliovirus outbreaks in the Horn of Africa: an assessment of acute flaccid paralysis surveillance and routine immunization systems in Kenya.

Background: Although the Horn of Africa region has successfully eliminated endemic poliovirus circulation, it remains at risk for reintroduction. International partners assisted Kenya in identifying gaps in the polio surveillance and routine immunization programs, and provided recommendations for improved surveillance and routine immunization during the health system decentralization process.

Methods: Structured questionnaires collected information about acute flaccid paralysis (AFP) surveillance resources, training, data monitoring, and supervision at provincial, district, and health facility levels.

Progress toward laboratory containment of poliovirus after polio eradication.

Background: The first steps (phase 1) toward laboratory containment of poliovirus after eradication are a national survey of biomedical facilities and a global inventory of such facilities retaining wild poliovirus (WPV) infectious and potentially infectious materials.

Methods: We reviewed published reports on national laboratory surveys and inventories of WPV materials from each of the 3 polio-free World Health Organization (WHO) regions (the European Region, completed in 2006; the Western Pacific Region, completed in 2008; and the Region of the Americas, completed in 2010), as well as reports on progress in polio-free countries of the remaining 3 regions (the African Region, the Eastern Mediterranean Region, and the WHO South-East Asia Region).

Results: Containment phase 1 activities are complete in 154 of 194 WHO Member States (79%), including all countries and areas of the polio-free regions and most polio-free countries in the remaining 3 regions.

Combined use of inactivated and oral poliovirus vaccines in refugee camps and surrounding communities - Kenya, December 2013.

Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, circulation of indigenous wild poliovirus (WPV) has continued without interruption in only three countries: Afghanistan, Nigeria, and Pakistan. During April-December 2013, a polio outbreak caused by WPV type 1 (WPV1) of Nigerian origin resulted in 217 cases in or near the Horn of Africa, including 194 cases in Somalia, 14 cases in Kenya, and nine cases in Ethiopia (all cases were reported as of March 10, 2014). During December 14-18, 2013, Kenya conducted the first-ever campaign providing inactivated poliovirus vaccine (IPV) together with oral poliovirus vaccine (OPV) as part of its outbreak response.