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Poliomyelitis (polio) was first targeted for eradication in 1988. Global efforts have led to eradication of 2 of the 3 wild poliovirus (WPV) serotypes (types 2 and 3), and only WPV type 1 (WPV1) remains endemic and only in Afghanistan and Pakistan. This report describes global polio immunization, surveillance activities and poliovirus epidemiology during January 2022-December 2023. Data are current as of 10 April 2024. In 2023, Afghanistan and Pakistan identified 12 WPV1 polio cases, as compared with 22 in 2022. WPV1 transmission was detected by systematic testing for poliovirus in sewage samples (environmental surveillance, ES) in 13 provinces in Afghanistan and Pakistan in 2021 and in 7 in 2022. The number of polio cases caused by circulating vaccine-derived poliovirus (cVDPV) (circulating vaccine virus strains that have reverted to neurovirulence) decreased from 881 in 2022 to 524 in 2023; cVDPV outbreaks (defined as either a cVDPV case with evidence of circulation or at least 2 positive ES isolates) occurred in 32 countries in 2023, including 8 that had not experienced a cVDPV outbreak in 2022. Despite reductions in the number of cases of paralytic polio since 2022, cVDPVs and WPV1 (in countries with endemic transmission) were more widespread in 2023. Renewed efforts to vaccinate children who are persistently missed in countries with endemic WPV1 transmission, strengthening of routine immunization (RI) programmes in high-risk countries and providing more effective cVDPV outbreak response are necessary to achieve further progress towards global polio eradication. L'objectif d'eradiquer la poliomyelite a ete formule pour la premiere fois en 1988. Des efforts a l'echelle mondiale ont conduit a l'eradication de 2 des 3 serotypes (types 2 et 3) de poliovirus sauvage (PVS), et seul le PVS de type 1 (PVS1) demeure endemique dans 2 pays, l'Afghanistan et le Pakistan. Le present rapport decrit la vaccination contre la poliomyelite, les activites de surveillance et l'epidemiologie des poliovirus dans le monde entre janvier 2022 et decembre 2023. Il s'appuie sur des donnees recueillies jusqu'au 10 avril 2024. En 2023, l'Afghanistan et le Pakistan ont identifie 12 cas de PVS1, contre 22 en 2022. La surveillance environnementale, qui consiste a analyser de maniere systematique des echantillons d'eaux usees a la recherche de poliovirus, a detecte une transmission de PVS1 dans 13 provinces d'Afghanistan et du Pakistan en 2021 et dans 7 provinces en 2022. Le nombre de cas de poliomyelite dus aux poliovirus circulants derives d'une souche vaccinale (PVDVc) (souches de virus vaccinaux circulants qui ont retrouve leur neurovirulence) est passe de 881 en 2022 a 524 en 2023; des flambees epidemiques de PVDVc (definies comme un cas de PVDVc associe a une circulation averee du virus ou comme au moins 2 isolats positifs issus de la surveillance environnementale) sont survenues dans 32 pays en 2023, parmi lesquels 8 qui n'avaient pas connu de flambee de PVDVc en 2022. Malgre la reduction du nombre de cas de poliomyelite paralytique depuis 2022, les PVDVc et le PVS1 ont davantage circule en 2023 dans les pays oU la transmission est endemique. Pour continuer a progresser vers l'eradication mondiale de la poliomyelite, il est necessaire de redoubler d'efforts pour vacciner les enfants qui echappent encore a la vaccination dans les pays oU la transmission du PVS1 est endemique, en renforcant les programmes de vaccination systematique dans les pays a haut risque et en assurant une riposte plus efficace aux flambees de PVDVc., Introduction Since establishment of the Global Polio Eradication Initiative (GPEI) in 1988, WPV types 2 and 3 have been eradicated, and WPV1 remains endemic only in Afghanistan and Pakistan. In [...]

Global eradication of indigenous wild poliovirus type 2 was certified in 2015 and that of type 3 in 2019. Since the launch of the Global Polio Eradication Initiative (GPEI) in [...]

Since the Global Polio Eradication Initiative (GPEI) began in 1988, transmission of wild poliovirus (WPV) has been interrupted in all countries except Afghanistan, Nigeria and Pakistan. WPV type 2 (WPV2) [...]

In 1988, when an estimated 350 000 cases of poliomyelitis occurred in 125 countries, the World Health Assembly resolved to eradicate polio globally. Transmission of wild poliovirus (WPV) continues uninterrupted [...]

In 1988, the World Health Assembly (WHA) resolved to eradicate polio worldwide. Since then, endemic transmission of wild poliovirus (WPV) has been interrupted in all countries except Afghanistan, Nigeria and [...]

Following the global declaration of indigenous wild poliovirus type 2 eradication in 2015, the world switched to oral polio vaccine (OPV) that removed the type 2 component. This 'switch' included the widespread introduction of inactivated poliovirus vaccine and the creation of a stockpile of monovalent type 2 OPV (mOPV2) to respond to potential polio virus Type 2 (PV2) outbreaks and events. With subsequent detection of outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2), it was necessary to use this stockpile for outbreak response. Not only were more outbreaks detected than anticipated in the first few years after the switch, but the number of supplemental immunization activities (SIAs) used to stop transmission was often high, and in many cases did not stop wider transmission. Use of mOPV type 2 led in some locations to the emergence of new outbreaks that required further use of the vaccine from the stockpile. In the following years, stockpile management became a critical element of the cVDPV2 outbreak response strategy and continued to evolve to include trivalent OPV and genetically stabilized 'novel OPV type 2' vaccines in the stockpile. An overview of this process and its evolution is presented to highlight several of these management challenges. The unpredictable vaccine demand, fixed production and procurement timelines, resource requirements, and multiple vaccine types contributes to the complexity of assuring appropriate vaccine availability for this critical programmatic need to stop outbreaks. [ABSTRACT FROM AUTHOR]

Objective This study aimed to estimate the incremental cost-effectiveness of supplementary immunization activities to prevent neonatal tetanus in the Loralai district of Pakistan. The supplemental immunization activities were carried out in two phases during 2001-03. Methods A state-transition model was used to estimate the effect of routine vaccination with tetanus toxoid as well as vaccination with tetanus toxoid during supplementary immunization activities. The model follows each woman in the target population from birth until the end of her childbearing years, using age-specific fertility data and vaccination history to determine the number of births at risk for neonatal tetanus. Recently published data on the incidence of neonatal tetanus from Loralai were used to determine the number of cases occurring with and without supplementary immunization activities. Data on the costs of the activities were collected from the UNICEF office in Balochistan and from the Provincial Health Department. Findings Using base-case assumptions we estimated that the supplementary immunization activities would prevent 280 cases of neonatal tetanus and 224 deaths from neonatal tetanus between 2001 and 2034. Implementation of the supplementary activities was relatively inexpensive. The cost per tetanus toxoid dose delivered was US$ 0.40. In the base-case analysis the cost per death averted was US$117.00 (95% confidence interval (CI) = US$ 78-205) and the cost per disability-adjusted life year (DALY) averted was US$ 3.61 (95% CI = US$ 2.43-6.39). Conclusion Compared with similar analyses of other interventions, the cost per DALY averted is a favourable cost-effectiveness ratio. However, if routine diphtheria-tetanus-pertussis vaccination coverage in the Loralai district had been higher (at a coverage rate of about 80%) the cost-effectiveness of the intervention would have been even more favourable, at US$ 2.65 per DALY averted. Keywords Tetanus/prevention and control; Infant, Newborn; Tetanus toxoid/administration and dosage/economics; Immunization, Secondary/economics; Disability evaluation; Costs and cost analysis; Cost-benefit analysis; Pakistan (source: MESH, NLM). Mots cles Tetanos/prevention et controle; Nouveau-ne; Anatoxine tetanique/administration et posologie/economie; Rappel vaccination/economie; Evaluation incapacitY; Cout et analyse coot; Analyse cout-benefice; Pakistan (source: MeSH, INSERM). Palabras clave Tetanos/prevencion y control; Recien nacido; Toxoide tetanico/administracion y dosificacion/economia; Inmunizacion secundaria/economia; Evaluacion de la incapacidad; Costos y analisis de costo; Analisis de costo-beneficio; Pakistan (fuente: DeCS, BIREME). [TEXT NOT REPRODUCIBLE IN ASCII.], Resume Prevention du tetanos neonatal au Pakistan : augmentation de rentabilite des activites de vaccination supplementaires Objectif La presente etude avait pour but d'estimer l'augmentation de rentabilite des activites de [...]

Among public health challenges in Afghanistan, communicable diseases still predominate because the epidemiologic transition to chronic disease has not yet occurred. Afghanistan's 10-year journey to improve its response to communicable disease is reflected in varying degrees of progress and innovation, all while long-standing conflict and geographic inaccessibility limit outreach and effective service delivery to vulnerable populations. Although Afghanistan is close to achieving polio elimination, other reportable communicable diseases are only slowly achieving their goals and objectives through targeted, sustained programmatic efforts. The introduction of disease early warning systems has allowed for identification and investigation of outbreaks within 48 hours. Tuberculosis case detection has risen over the last 10 years, and treatment success rates have been sustained at World Health Organization targets over the last 5 years at 85%. These successes are in large part due to increased government commitment, Global Fund support, training of community health workers and improved laboratory capabilities. Malaria cases dropped between 2002 and 2010. HIV/AIDS has been kept at low levels except in only certain sub-sectors of the population. In order to build on these achievements, Afghanistan will need a comprehensive strategy for all communicable diseases, with better human and infrastructure development, better multi-sectoral development and international collaboration. [ABSTRACT FROM PUBLISHER]

In 1988, poliomyelitis (polio) was targeted for eradication. Global efforts have led to the eradication of two of the three wild poliovirus (WPV) serotypes (types 2 and 3), with only WPV type 1 (WPV1) remaining endemic, and only in Afghanistan and Pakistan. This report describes global polio immunization, surveillance activities, and poliovirus epidemiology during January 2022-December 2023, using data current as of April 10, 2024. In 2023, Afghanistan and Pakistan identified 12 total WPV1 polio cases, compared with 22 in 2022. WPV1 transmission was detected through systematic testing for poliovirus in sewage samples (environmental surveillance) in 13 provinces in Afghanistan and Pakistan, compared with seven provinces in 2022. The number of polio cases caused by circulating vaccine-derived polioviruses (cVDPVs; circulating vaccine virus strains that have reverted to neurovirulence) decreased from 881 in 2022 to 524 in 2023; cVDPV outbreaks (defined as either a cVDPV case with evidence of circulation or at least two positive environmental surveillance isolates) occurred in 32 countries in 2023, including eight that did not experience a cVDPV outbreak in 2022. Despite reductions in paralytic polio cases from 2022, cVDPV cases and WPV1 cases (in countries with endemic transmission) were more geographically widespread in 2023. Renewed efforts to vaccinate persistently missed children in countries and territories where WPV1 transmission is endemic, strengthen routine immunization programs in countries at high risk for poliovirus transmission, and provide more effective cVDPV outbreak responses are necessary to further progress toward global polio eradication., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Certification of global eradication of indigenous wild poliovirus type 2 occurred in 2015 and of type 3 in 2019. Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988 and broad use of live, attenuated oral poliovirus vaccine (OPV), the number of wild poliovirus cases has declined >99.99% (1). Genetically divergent vaccine-derived poliovirus* (VDPV) strains can emerge during vaccine use and spread in underimmunized populations, becoming circulating VDPV (cVDPV) strains, and resulting in outbreaks of paralytic poliomyelitis. † In April 2016, all oral polio vaccination switched from trivalent OPV (tOPV; containing vaccine virus types 1, 2, and 3) to bivalent OPV (bOPV; containing types 1 and 3) (2). Monovalent type 2 OPV (mOPV2) is used in response campaigns to control type 2 cVDPV (cVDPV2) outbreaks. This report presents data on cVDPV outbreaks detected during January 2018-June 2019 (as of September 30, 2019). Compared with January 2017-June 2018 (3), the number of reported cVDPV outbreaks more than tripled, from nine to 29; 25 (86%) of the outbreaks were caused by cVDPV2. The increase in the number of outbreaks in 2019 resulted from VDPV2 both inside and outside of mOPV2 response areas. GPEI is planning future use of a novel type 2 OPV, stabilized to decrease the likelihood of reversion to neurovirulence. However, all countries must maintain high population immunity to decrease the risk for cVDPV emergence. Cessation of all OPV use after certification of polio eradication will eliminate the risk for VDPV emergence., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Since the Global Polio Eradication Initiative (GPEI) began in 1988, transmission of wild poliovirus (WPV) has been interrupted in all countries except Afghanistan, Nigeria, and Pakistan. WPV type 2 (WPV2) was declared eradicated in 2015; WPV type 3 has not been detected since 2012 (1). After the certification of the eradication of WPV2, a global switch from trivalent oral poliovirus vaccine (tOPV, containing vaccine virus types 1, 2, and 3) to bivalent oral poliovirus vaccine (bOPV, containing types 1 and 3) was completed in April 2016. Nigeria last reported WPV type 1 (WPV1) cases in 2016. This report describes global progress toward poliomyelitis eradication during January 1, 2017-March 31, 2019, and updates previous reports (1,2). Afghanistan and Pakistan reported their lowest annual number of WPV cases (22) in 2017; however, 33 WPV1 cases were reported in 2018. During January-March 2019 (as of May 3), 12 WPV1 cases had been reported worldwide, four more than the eight reported during the corresponding period in 2018. The occurrence of polio cases caused by circulating vaccine-derived poliovirus (cVDPV) is rare and occurs where oral poliovirus vaccine (OPV) coverage has been low and vaccine virus reverts to neurovirulence (3). Eight countries (Democratic Republic of the Congo [DRC], Indonesia, Mozambique, Niger, Nigeria, Papua New Guinea, Somalia, and Syria) reported 210 cVDPV cases during 2017-2019 (as of May 3). Reaching children during supplemental immunization activities (SIAs), accessing mobile populations at high risk, and variations in surveillance performance represent ongoing challenges. Innovative efforts to vaccinate every child and strengthen coordination efforts between Afghanistan and Pakistan will help achieve eradication. For cVDPV outbreak responses to promptly stop transmission, intensified programmatic improvements are needed to make the responses more effective and limit the risk for generating future outbreaks., Competing Interests: All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

In 1988, when an estimated 350,000 cases of poliomyelitis occurred in 125 countries, the World Health Assembly resolved to eradicate polio globally. Transmission of wild poliovirus (WPV) continues uninterrupted in only three countries (Afghanistan, Nigeria, and Pakistan) (1), and among the three serotypes, WPV type 1 (WPV1) remains the only confirmed circulating type. This report describes global progress toward polio eradication during January 2016-March 2018, and updates previous reports (2). In 2017, 22 WPV1 cases were reported, a 41% decrease from the 37 WPV1 cases reported in 2016. As of April 24, 2018, eight WPV1 cases have been reported (seven in Afghanistan and one in Pakistan), compared with five cases during the same period in 2017. In Pakistan, continuing WPV1 transmission has been confirmed in multiple areas in 2018 by isolation from wastewater samples. In Nigeria, ongoing endemic WPV1 transmission was confirmed in 2016 (3); although WPV was not detected in 2017 or in 2018 to date, limitations in access for vaccination and surveillance in insurgent-held areas in northeastern Nigeria might permit continued undetected poliovirus transmission. Substantial progress toward polio eradication has continued in recent years; however, interruption of WPV transmission will require overcoming remaining challenges to reaching and vaccinating every missed child. Until poliovirus eradication is achieved, all countries must remain vigilant by maintaining high population immunity and sensitive poliovirus surveillance., Competing Interests: No conflicts of interest were reported.

The Global Polio Eradication Initiative (GPEI) has made substantial progress since its launch in 1988; only 37 wild poliovirus type 1 (WPV1) cases were detected in 2016, the lowest annual count ever. Wild poliovirus type 3 has not been detected since November 2012, and wild poliovirus type 2 was officially declared eradicated in September 2015. This success is attributable to the wide use of live oral poliovirus vaccines (OPVs). Since 2001, numerous outbreaks were caused by the emergence of genetically divergent vaccine-derived polioviruses (VDPVs) whose genetic drift from the parental OPV strains indicates prolonged replication or circulation (1). In 2015, circulating VDPV type 2 (cVDPV2) outbreaks were detected in five countries worldwide (Nigeria, Pakistan, Guinea, Burma, and South Sudan), and VDPV2 single events were reported in 22 countries. These events prompted the GPEI to withdraw the type 2 component (Sabin2) of trivalent OPV (tOPV) in a globally coordinated, synchronized manner in April 2016 (2,3), at which time all OPV-using countries switched to using bivalent OPV (bOPV), containing Sabin types 1 and 3. This report details for the first time the virologic tracking of elimination of a live vaccine that has been withdrawn from routine and mass immunization systems worldwide (3). To secure elimination, further monitoring is warranted to detect any use of tOPV or monovalent OPV type 2 (mOPV2).

In 1988, the World Health Assembly of the World Health Organization (WHO) resolved to eradicate polio worldwide. Wild poliovirus (WPV) transmission has been interrupted in all but three countries (Afghanistan, Nigeria, and Pakistan). No WPV type 2 cases have been detected worldwide since 1999, and the last WPV type 3 case was detected in Nigeria in November 2012; since 2012, only WPV type 1 has been detected. Circulating vaccine-derived poliovirus (cVDPV), usually type 2, continues to cause cases of paralytic polio in communities with low population immunity. In 2012, the World Health Assembly declared global polio eradication "a programmatic emergency for global public health", and in 2014, WHO declared the international spread of WPV to previously polio-free countries to be "a public health emergency of international concern". This report summarizes global progress toward polio eradication during 2014-2015 and updates previous reports. In 2014, a total of 359 WPV cases were reported in nine countries worldwide. Although reported WPV cases increased in Pakistan and Afghanistan, cases in Nigeria decreased substantially in 2014, and encouraging progress toward global WPV transmission interruption has occurred. Overcoming ongoing challenges to interruption of WPV transmission globally will require sustained programmatic enhancements, including improving the quality of supplementary immunization activities (SIAs) to interrupt transmission in Afghanistan and Pakistan and to prevent WPV exportation to polio-free countries.

In 2012, the World Health Assembly declared the completion of polio eradication a programmatic emergency for global public health and called for a comprehensive polio endgame strategy. Afghanistan and Pakistan are two of the three remaining countries (the other is Nigeria) where circulation of indigenous wild poliovirus (WPV) has never been interrupted. This report updates previous reports and describes polio eradication activities and progress in Afghanistan and Pakistan during January 2013-August 2014. In Afghanistan, 14 WPV cases were reported in 2013, compared with 37 cases in 2012; nine cases were reported during January-August 2014, compared with six cases during the same period in 2013. In Pakistan, 93 WPV cases were reported in 2013, compared with 58 cases in 2012; 170 cases were reported during January-August 2014, compared with 33 cases during the same period in 2013. All WPV cases reported during January 2013-August 2014 were WPV type 1 (WPV1). Vaccination campaigns have been banned since June 2012 in specific areas in Pakistan, where an estimated 300,000 children aged <5 years reside and where 69% of WPV cases have occurred in 2014. To accomplish the objectives of the Polio Eradication and Endgame Strategic Plan for 2013-2018 both countries should continue to negotiate access of vaccinators to insecure and temporarily inaccessible areas, improve immunization program performance to reach more children in accessible areas, and ensure that political and health leaders at all levels are fully committed to the program, including being committed to providing financial resources needed to fully implement all the recommendations of external technical advisory groups. Both countries should also continue to strengthen cross-border collaboration to improve surveillance and case detection, coordinate outbreak response, and maximize vaccination coverage of children moving between the two countries.