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Current Opinion in Neurology Jun 2023Recent outbreaks of poliomyelitis in countries that have been free of cases for decades highlight the challenges of eradicating polio in a globalized interconnected... (Review)
Review
PURPOSE OF REVIEW
Recent outbreaks of poliomyelitis in countries that have been free of cases for decades highlight the challenges of eradicating polio in a globalized interconnected world beset with a novel viral pandemic. We provide an epidemiological update, advancements in vaccines, and amendments in public health strategy of poliomyelitis in this review.
RECENT FINDINGS
Last year, new cases of wild poliovirus type 1 (WPV1) were documented in regions previously documented to have eradicated WPV1 and reports of circulating vaccine-derived poliovirus type 2 (cVDPV2) and 3 (cVDPV3) in New York and Jerusalem made international headlines. Sequencing of wastewater samples from environmental surveillance revealed that the WPV1 strains were related to WPV1 lineages from endemic countries and the cVDPV2 strains from New York and Jerusalem were not only related to each other but also to environmental isolates found in London. The evidence of importation of WPV1 cases from endemic countries, and global transmission of cVDPVs justifies renewed efforts in routine vaccination programs and outbreak control measures that were interrupted by the COVID-19 pandemic. After the novel oral poliovirus vaccine type 2 (nOPV2) received emergency authorization for containment of cVDPV2 outbreaks in 2021, subsequent reduced incidence, transmission rates, and vaccine adverse events, alongside increased genetic stability of viral isolates substantiates the safety and efficacy of nOPV2. The nOPV1 and nOPV3 vaccines, against type 1 and 3 cVDPVs, and measures to increase accessibility and efficacy of inactivated poliovirus vaccine (IPV) are in development.
SUMMARY
A revised strategy utilizing more genetically stable vaccine formulations, with uninterrupted vaccination programs and continued active surveillance optimizes the prospect of global poliomyelitis eradication.
Topics: Humans; Poliovirus; Pandemics; COVID-19; Poliovirus Vaccine, Oral; Poliomyelitis; Disease Outbreaks
PubMed: 37078665
DOI: 10.1097/WCO.0000000000001156 -
Cadernos de Saude Publica 2020This article's objective is to review the "state of the art" in the progress, obstacles, and strategies for achieving global polio eradication. Poliomyelitis control...
This article's objective is to review the "state of the art" in the progress, obstacles, and strategies for achieving global polio eradication. Poliomyelitis control measures began in the 1960s with the advent of two vaccines, the oral polio vaccine (OPV) and the inactivated polio vaccine (IPV). From 1985 to 2020, strategies were implemented to reach the goal of eradication of wild poliovirus (WPV). Following the success with the interruption of indigenous WPV transmission in the Americas, the goal of global eradication was launched. We describe the process of eradication in four historical stages: (1) The advent of the inactivated and oral polio vaccines launched the age of poliomyelitis control; (2) The massive and simultaneous use of OPV had a significant impact on WPV transmission in the late 1970s in Brazil; (3) Domestic and international public policies set the goal of eradication of indigenous WPV transmission in the Americas and defined the epidemiological strategies to interrupt transmission; and (4) The implementation of eradication strategies interrupted indigenous WPV transmission in nearly all regions of the world except Pakistan and Afghanistan, where in 2020 the WPV1 transmission chains have challenged the strategies for containment of the virus. Meanwhile, the persistence and dissemination of circulation of OPV-derived poliovirus in countries with low vaccination coverage, plus the difficulties in replacing OPV with IPV, are currently the obstacles to eradication in the short term. Finally, we discuss the strategies for overcoming the obstacles and challenges in the post-eradication era.
Topics: Afghanistan; Brazil; Disease Eradication; Humans; Immunization Programs; Poliomyelitis; Poliovirus Vaccine, Oral
PubMed: 33146314
DOI: 10.1590/0102-311X00145720 -
The American Journal of Tropical... Dec 2019Poliovirus (PV) environmental surveillance was established in Haiti in three sites each in Port-au-Prince and Gonaïves, where sewage and fecal-influenced environmental... (Comparative Study)
Comparative Study
Poliovirus (PV) environmental surveillance was established in Haiti in three sites each in Port-au-Prince and Gonaïves, where sewage and fecal-influenced environmental open water channel samples were collected monthly from March 2016 to February 2017. The primary objective was to monitor for the emergence of vaccine-derived polioviruses (VDPVs) and the importation and transmission of wild polioviruses (WPVs). A secondary objective was to compare two environmental sample processing methods, the gold standard two-phase separation method and a filter method (bag-mediated filtration system [BMFS]). In addition, non-polio enteroviruses (NPEVs) were characterized by next-generation sequencing using Illumina MiSeq to provide insight on surrogates for PVs. No WPVs or VDPVs were detected at any site with either concentration method. Sabin (vaccine) strain PV type 2 and Sabin strain PV type 1 were found in Port-au-Prince, in March and April samples, respectively. Non-polio enteroviruses were isolated in 75-100% and 0-58% of samples, by either processing method during the reporting period in Port-au-Prince and Gonaïves, respectively. Further analysis of 24 paired Port-au-Prince samples confirmed the detection of a human NPEV and echovirus types E-3, E-6, E-7, E-11, E-19, E-20, and E-29. The comparison of the BMFS filtration method to the two-phase separation method found no significant difference in sensitivity between the two methods (mid--value = 0.55). The experience of one calendar year of sampling has informed the appropriateness of the initially chosen sampling sites, importance of an adequate PV surrogate, and robustness of two processing methods.
Topics: Disease Eradication; Environmental Monitoring; Feces; Filtration; Haiti; High-Throughput Nucleotide Sequencing; Humans; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Sewage; Water Microbiology
PubMed: 31701857
DOI: 10.4269/ajtmh.19-0469 -
Emerging Infectious Diseases Feb 2021Since May 2019, the Central African Republic has experienced a poliomyelitis outbreak caused by type 2 vaccine-derived polioviruses (VDPV-2s). The outbreak affected...
Since May 2019, the Central African Republic has experienced a poliomyelitis outbreak caused by type 2 vaccine-derived polioviruses (VDPV-2s). The outbreak affected Bangui, the capital city, and 10 districts across the country. The outbreak resulted from several independent emergence events of VDPV-2s featuring recombinant genomes with complex mosaic genomes. The low number of mutations (<20) in the viral capsid protein 1-encoding region compared with the vaccine strain suggests that VDPV-2 had been circulating for a relatively short time (probably <3 years) before being isolated. Environmental surveillance, which relies on a limited number of sampling sites in the Central African Republic and does not cover the whole country, failed to detect the circulation of VDPV-2s before some had induced poliomyelitis in children.
Topics: Central African Republic; Child; Disease Outbreaks; Humans; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral
PubMed: 33496226
DOI: 10.3201/eid2702.203173 -
Reviews in Medical Virology May 2023Although the Global Polio Eradication Initiative has been largely successful in elimination of polio from various parts of the world, sporadic local outbreaks in...
Although the Global Polio Eradication Initiative has been largely successful in elimination of polio from various parts of the world, sporadic local outbreaks in non-endemic areas continue to pose a threat to global polio eradication efforts. In the two endemic countries, Pakistan and Afghanistan, a staggering 176 cases of wild poliovirus 1 (WPV1) were reported in 2019. In 2020 alone, 959 cases of Circulating Vaccine Derived Poliovirus 2 were reported globally from 27 countries. After staying polio-free for years, cases of WPV were detected in Malawi and Mozambique in 2022. The roots of the reported strains matched with the WPV strain from Pakistan. The emergence of WPV cases in Malawi and Mozambique underscores the fact that WPV still has the chance to spread beyond the Afghanistan-Pakistan region and sustained efforts are required for its complete eradication. In the case of smallpox, surveillance-containment was the key to eradication as many countries had already eradicated smallpox and the bigger concern was to track and contain any new cases emerging. Smallpox eradication followed a comprehensive plan which included elements like quality control and standardisation of vaccination protocols. Governments all over the world should prioritise immunisation drives, surveillance, and awareness campaigns to achieve the dream of a polio-free world.
Topics: Humans; Smallpox; Immunization Programs; Population Surveillance; Global Health; Poliomyelitis; Disease Eradication; Poliovirus
PubMed: 36426668
DOI: 10.1002/rmv.2409 -
Expert Review of Vaccines 2023Achieving polio eradication requires ensuring the delivery of sufficient supplies of the right vaccines to the right places at the right times. Despite large global... (Review)
Review
BACKGROUND
Achieving polio eradication requires ensuring the delivery of sufficient supplies of the right vaccines to the right places at the right times. Despite large global markets, decades of use, and large quantity purchases of polio vaccines by national immunization programs and the Global Polio Eradication Initiative (GPEI), forecasting demand for the oral poliovirus vaccine (OPV) stockpile remains challenging.
RESEARCH DESIGN AND METHODS
We review OPV stockpile experience compared to pre-2016 expectations, actual demand, and changes in GPEI policies related to the procurement and use of type 2 OPV vaccines. We use available population and immunization schedule data to explore polio vaccine market segmentation, and its role in polio vaccine demand forecasting.
RESULTS
We find that substantial challenges remain in forecasting polio vaccine needs, mainly due to (1) deviations in implementation of plans that formed the basis for earlier forecasts, (2) lack of alignment of tactics/objectives among GPEI partners and other key stakeholders, (3) financing, and (4) uncertainty about development and licensure timelines for new polio vaccines and their field performance characteristics.
CONCLUSIONS
Mismatches between supply and demand over time have led to negative consequences associated with both oversupply and undersupply, as well as excess costs and potentially preventable cases.
Topics: Humans; Poliovirus Vaccine, Oral; Disease Eradication; Poliovirus Vaccines; Poliomyelitis; Vaccination; Immunization Programs; Poliovirus Vaccine, Inactivated; Global Health
PubMed: 37747090
DOI: 10.1080/14760584.2023.2263096 -
The Journal of Infectious Diseases Oct 2022
Topics: Disease Eradication; Humans; Poliomyelitis
PubMed: 35417552
DOI: 10.1093/infdis/jiac132 -
Lancet (London, England) May 2022
Topics: Disease Eradication; Humans; Poliomyelitis
PubMed: 35644146
DOI: 10.1016/S0140-6736(22)00973-4 -
The Lancet. Microbe Jan 2022
Topics: Afghanistan; Humans; Poliomyelitis; Poliovirus; Vaccination
PubMed: 35544112
DOI: 10.1016/S2666-5247(21)00336-0 -
The Pan African Medical Journal 2023Nigeria made a coordinated effort to be certified by the World Health Organization's African Region for interrupting endemic transmission of wild poliovirus type-1... (Review)
Review
Nigeria made a coordinated effort to be certified by the World Health Organization's African Region for interrupting endemic transmission of wild poliovirus type-1 (WPV1) in August 2020 as a response to the resurgence of WPV1 cases in August 2016 after going two years without a case. The NEOC Data Working Group (DWG) was instrumental in providing quality and timely surveillance and campaign information for decision-making in order to interrupt WPV1 transmission and provide data toward documentation of its elimination for regional certification. The polio pre-campaign dashboard was used to assess the level of preparedness for Oral Poliovirus Vaccine (OPV) polio supplementary immunization activities (SIA) at three weeks, two weeks, one week, and three days to the start of each campaign implemented during 2016-2020. The administrative tally sheet, independent monitoring survey, and Lot Quality Assurance Sampling (LQAS) survey data collected and shared from the implementation level were analyzed by the EOC DWG to provide information by person, place, and time. Using a 90% threshold in LQAS surveys defining quality SIAs, the proportion of Local Government Areas (LGAs) in Nigeria's states in which post-SIA LQAS surveys were conducted that met this threshold were assessed over time. The highest level of preparedness attained by 3 days to a polio campaign during August 2016-February 2020 was 95% and the lowest attained was 77%. The admin, independent monitoring, and LQAS data analysis results were given to EOC working groups for assessing the performance and quality of each campaign. Twenty-twenty five percent of LGAs that failed LQAS were identified for repeat vaccination. Further, acute flaccid paralysis and environmental surveillance data and laboratory results were analyzed and shared with NEOC and partners. The government and partners used the information generated by the Data Working Group to take evidence-based action including determining the scope of the polio campaign, intensification of surveillance and routine immunization activities, and special intervention activities. On average, 12% of the 774 LGAs were identified as polio high risk LGAs for intervention using selected surveillance, routine immunization (RI), SIAs, and other relevant data sets. National Emergency Operation Centre Data Working Group provided quality and timely information that supported decision-making processes for the polio program in Nigeria. The quality and timely information enabled the NEOC to make evidence-based and timely decisions that contributed to gap identification and decision-making.
Topics: Humans; Lot Quality Assurance Sampling; Disease Eradication; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Nigeria; Immunization Programs
PubMed: 38370106
DOI: 10.11604/pamj.supp.2023.45.2.39489