Erradicación de la poliomielitis en España: ¿qué ha pasado en la última década? / Eradication of poliomyelitis in Spain: What has happened in the last decade?

Al cumplirse sesenta años desde el inicio de la campaña de vacunación frente a la poliomielitis en España, se destaca el importante hito en el control de la enfermedad que ha supuesto el cambio desde una incidencia de más de 2.000 casos anuales en la década de los 60 a una ausencia mantenida de poliovirus (PV) salvaje desde 1988. A pesar del impacto negativo observado en las coberturas de vacunación de poliomielitis al inicio de la pandemia de COVID-19, estas se fueron recuperando, alcanzando un 98,2% en la primovacunación en 2022. En la última década, se han identificado dos elementos esenciales para mantener el objetivo de eliminación de la poliomielitis y que, además, refuerzan la importancia de mantener altas coberturas de vacunación: los sistemas de vigilancia epidemiológica robustos y la respuesta rápida a las alertas para proteger a la población vulnerable y evitar la circulación del virus. Es crucial interrumpir la transmisión a nivel internacional para lograr la erradicación, manteniendo una vigilancia continua de alta calidad y una coordinación efectiva entre los diferentes niveles frente a cualquier detección de PV, ya sea salvaje o derivado de la vacuna.(AU)

On the 60th anniversary of the initiation of the polio vaccination campaign in Spain, the significant milestone in achieving disease control is highlighted. There has been a shift from an incidence of over 2,000 yearly cases in the 1960s to a sustained absence of wild poliovirus (WPV) since 1988. Despite the observed negative impact on polio vaccination coverage at the onset of the COVID-19 pan-demic, these rates gradually recovered, reaching 98.2% in primary vaccination in 2022. Over the past decade, two essential elements have been identified to maintain the goal of polio elimination and that reinforces the importance of sustaining high vaccination co-verage: robust epidemiological surveillance systems and a swift response to alerts to protect the vulnerable population and prevent virus reintroduction. In order to achieve eradication, it is crucial to interrupt international transmission and maintain continuous high-quality surveillance and effective coordination across different levels in response to any detection of PV, wild or vaccine derived.This article aimed to provide a comprehensive view of the polio eradication situation in Spain, focusing on the key events that occu-rred in the last decade and the present and future challenges.(AU)

Establishment of the Daucus carota SMC-1 Cell Suspension Line for Poliovirus Vaccine Development.

The development of virus-free, oral vaccines against poliovirus capable of inducing mucosal protective immunity is needed to safely combat this pathogen. In the present study, a carrot cell line expressing the poliovirus VP2 antigen was established at the level of callus and cell suspensions, exploring the effects of culture media (MS and B5), supplementation with urea, phytoregulators (2,4-D : KIN), and light conditions (continuous light, photoperiod, and total darkness). The best callus growth was obtained on B5 medium supplemented with 2 mg/L of 2,4-D + 2 mg/L kinetin and 0.0136 g/L of urea and in continuous light conditions. Suspension cultures of the SMC-1 line in 250 mL Erlenmeyer flasks had a maximum growth of 16.07 ± 0.03 g/L DW on day 12 with a growth rate of µ=0.3/d and a doubling time of 2.3 days. In a 2 L airlift bioreactor, the biomass yield achieved was 25.6 ± 0.05 g/L DW at day 10 with a growth rate of µ= 0.58/d and doubling time of 1.38 d. Cell growth was 1.5 times higher in bioreactors than in shake flasks, highlighting that both systems resulted in the accumulation of VP2 throughout the time in culture. The maximum VP2 yield in flasks was 387.8 µg/g DW at day 21, while in the reactor it was 550.2 µg/g DW at day 18. In conclusion, bioreactor-based production of the VP2 protein by the SMC-1 suspension cell line offers a higher productivity when compared to flask cultures, offering a key perspective to produce low-cost vaccines against poliomyelitis.

16th meeting of the Regional Certification Commission for the Polio Endgame in the Region of the Americas: Meeting report. 24- 27 July 2023, Panama City, Panama

The 16th Meeting of the Regional Certification Commission (RCC) for Polio Eradication in the Region of the Americas was held in Panama City, Panama, from July 24 to 27 2023. During the meeting, the RCC discussed and validated the annual reports of 22 countries and the report of the Caribbean subregion, which includes information from 13 countries and 9 territories. The reports were presented with information on the performance of the polio vaccination program and the eradication status in 2022. All RCC members discussed and approved the general recommendations, country validation results, and the report. end of the meeting.

Polio outbreak response, Yemen.

Problem: A decrease in vaccine coverage in conflict-affected areas has placed Yemen at higher risk of polio outbreaks caused by vaccine-derived poliovirus strains. Approach: In response to polio outbreaks, the Yemeni health ministry and partners initiated multiple vaccination campaigns to deliver vaccines to children. We also implemented several measures to enhance communication, education, health promotion and hygiene, especially in camps for internally displaced people. Local setting: In 2009, Yemen achieved polio-free status and maintained it until 2019. However, the ongoing political conflict since 2015, coupled with challenges in delivering the polio vaccine to conflict-affected areas, resulted in two polio outbreaks: 35 cases caused by vaccine-derived poliovirus strain 1 between 2019 and 2021, and 230 cases due to vaccine-derived poliovirus strain 2 between November 2021 and December 2022. Relevant changes: In response to the first outbreak, by the end of 2020, we vaccinated 7.2 million children through nationwide vaccination campaigns, except in Sa'ada governorate due to a ban by the authorities. By the end of 2021, 3 800 313 children younger than 5 years had received polio vaccines. For the second outbreak, by the end of 2022, 4 463 389 vaccines had been given to children younger than 10 years, and 1 217 423 to those younger than 5 years. Lessons learnt: Vaccination campaigns in conflict-affected areas with low vaccine coverage remain crucial in eradicating polio. Efforts are needed to reach vulnerable groups such as displaced populations. Advocacy, communication and social mobilization actions help ensure broader public inclusion and participation in vaccination efforts to prevent polio outbreaks.

Oral polio vaccine stockpile modeling: insights from recent experience.

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.

The role of a genetically stable, novel oral type 2 poliovirus vaccine in the poliomyelitis endgame

[ABSTRACT]. Poliovirus infection causes paralysis in up to 1 in 200 infected persons. The use of safe and effective inactivated poliovirus vaccines and live attenuated oral poliovirus vaccines (OPVs) means that only two pockets of wild- type poliovirus type 1 remain, in Afghanistan and Pakistan. However, OPVs can revert to virulence, causing outbreaks of circulating vaccine-derived poliovirus (cVDPV). During 2020–2022, cVDPV type 2 (cVDPV2) was responsible for 97–99% of poliomyelitis cases, mainly in Africa. Between January and August 2022, cVDPV2 was detected in sewage samples in Israel, the United Kingdom and the United States of America, where a case of acute flaccid paralysis caused by cVDPV2 also occurred. The Pan American Health Organization has warned that Brazil, the Dominican Republic, Haiti and Peru are at very high risk for the reintroduction of polio- virus and an additional eight countries in Latin America are at high risk, following dropping vaccination rates (average 80% coverage in 2022). Sabin type 2 monovalent OPV has been used to control VDPV2 outbreaks, but its use could also lead to outbreaks. To address this issue, a more genetically stable, novel OPV2 (nOPV2) was developed against cVDPV2 and in 2020 was granted World Health Organization Emergency Use Listing. Rolling out a novel vaccine under the Emergency Use Listing in mass settings to contain outbreaks requires unique local regulatory and operational preparedness.

[RESUMEN]. La infección por poliovirus ocasiona parálisis en hasta 1 de cada 200 personas infectadas. La utilización de vacunas con poliovirus inactivados y de vacunas antipoliomielíticas orales con poliovirus vivos atenuados (OPV) seguras y eficaces ha logrado que solo queden dos focos de poliovirus salvaje de tipo 1, en Afganistán y Pakistán. Sin embargo, las vacunas con OPV pueden revertir a la virulencia y producir brotes de poliovi- rus circulantes de origen vacunal (cVDPV). Durante el período 2020-2022, el cVDPV de tipo 2 (cVDPV2) fue la causa del 97-99% de los casos de poliomielitis, sobre todo en África. Entre enero y agosto del 2022, se encontró el cVDPV2 en muestras de aguas residuales en Estados Unidos de América, donde se produjo un caso de parálisis flácida aguda por el cVDPV2, Israel y Reino Unido y. La Organización Panamericana de la Salud ha advertido que, tras la caída de las tasas de vacunación (con una cobertura promedio del 80% en el 2022), Brasil, Haití, Perú y República Dominicana corren un riesgo muy alto de reintroducción del poliovirus, en tanto que otros ocho países de América Latina se encuentran en una situación de alto riesgo. La OPV mon- ovalente de tipo 2 de Sabin se ha utilizado para controlar los brotes de VDPV2, pero su empleo también podría ocasionar brotes. Para hacer frente a este problema, se creó una nueva OPV2 (nOPV2) contra el cVDPV2, genéticamente más estable, que en el 2020 se incluyó en la lista de uso en emergencias de la Organización Mundial de la Salud. El despliegue a gran escala de una nueva vacuna incluida en la lista de uso en emergen- cias con el fin de contener los brotes exige una extraordinaria preparación regulatoria y operativa local.

[RESUMO]. A infecção pelo poliovírus causa paralisia em 1 de cada 200 pessoas infectadas. O uso de vacinas seguras e eficazes, tanto vacinas inativadas contra o poliovírus quanto vacinas orais contendo poliovírus atenuado (VOP), significa que restam apenas dois bolsões de poliovírus selvagem tipo 1, um no Afeganistão e outro no Paquistão. No entanto, a VOP pode reverter à virulência, causando surtos de poliovírus circulante derivado de vacina (cPVDV). No período 2020-2022, o cPVDV tipo 2 (cPVDV2) foi responsável por 97% a 99% dos casos de poliomielite, principalmente na África. Entre janeiro e agosto de 2022, o cPVDV2 foi detectado em amostras de esgoto em Israel, no Reino Unido e nos Estados Unidos da América, onde também houve um caso de paralisia flácida aguda causada pelo cPVDV2. A Organização Pan-Americana da Saúde alertou que, devido à queda nas taxas de vacinação (cobertura média de 80% em 2022), o Brasil, o Haiti, o Peru e a República Dominicana correm um risco muito alto de reintrodução do poliovírus e outros oito países da América Latina correm um risco alto. A VOP monovalente Sabin tipo 2 tem sido usada para controlar surtos de PVDV2, mas seu uso também pode levar a surtos. Para resolver esse problema, foi desenvolvida uma nova VOP2 (nVOP2), mais estável geneticamente, para combater o cPVDV2. Em 2020, a nVOP2 entrou na Lista de Uso Emergencial da Organização Mundial da Saúde. A distribuição de uma nova vacina incluída na Lista de Uso Emergencial em contextos de massa para conter surtos requer medidas originais de preparação operacional e regulatória em âmbito local.

Prevalence of poliovirus neutralizing antibodies in Italian population: A systematic review and meta-analysis.

INTRODUCTION: The introduction of anti-poliomyelitis vaccines has driven progress toward the global eradication of wild polioviruses, a millennium goal of the World Health Organization. With the vaccination campaigns carried out since 1964, in 2002 Italy was certified polio-free, considering that no cases had been recorded since 1983. Nevertheless, it is crucial to guarantee high level of immunization coverage also in low-endemicity countries, considering that sporadic polio cases can be recorded. To evaluate the presence of susceptible subjects in the population, seroepidemiological studies are key actions. METHODS: We conducted a systematic review of the relevant literature to evaluate the prevalence of anti-PV neutralizing antibodies in Italian population. Seven studies, selected among scientific articles available in MEDLINE/PubMed, ISI Web of Knowledge and Scopus and published from January 1, 2012, to November 15, 2022, were included. RESULTS: The pooled prevalence of subjects without PV1 neutralizing antibodies was 6.4% (95%CI = 0.5-16.9), for PV2 it was 5.3% (95%CI = 0.4-14.2), and for PV3 it was 13.0% (95%CI = 4.0-25.7; I2 = 98.5%). Levels of neutralizing antibodies appears to decrease with increasing age; this decline is a proxy for the real risk factor, which is the time since the last vaccine dose. CONCLUSIONS: Public health institutions must be aware of the risk of reintroduction of wild PV in polio-free countries and therefore they must keep high level of immunization in population and reinforce the active surveillance systems.

PAHO Strategic Response Plan and Appeal: Polio

This publication contains information on the response plan and financial appeal to respond to the emergency declared in relations to Polio.

Polio eradication: Addressing the hurdles on the last mile.

1988, the World Health Assembly committed to eradicate poliomyelitis, a viral disease that can cause permanent paralysis. Today, only type 1 of the three wild poliovirus types remains circulating in limited geographic areas following widespread use of different poliovirus vaccines. While we are close to zero new cases of wild polio, it is a fragile situation, and there are many remaining and new hurdles to overcome. Here, experts discuss how to address them.

Descriptive epidemiology of poliomyelitis cases due to wild poliovirus type 1 and wild poliovirus type 3 in Nigeria, 2000-2020.

Introduction: in August 2020, the World Health Organization African Region was certified free of wild poliovirus (WPV) when Nigeria became the last African country to interrupt wild poliovirus transmission. The National Polio Emergency Operations Center instituted in 2012 to coordinate and manage Nigerian polio eradication efforts reviewed the epidemiology of WPV cases during 2000-2020 to document lessons learned. Methods: we analyzed reported WPV cases by serotype based on age, oral poliovirus vaccine immunization history, month and year of reported cases, and annual geographic distribution based on incidence rates at the Local Government Area level. The observed trends of cases were related to major events and the poliovirus vaccines used during mass vaccination campaigns within the analysis period. Results: a total of 3,579 WPV type 1 and 1,548 WPV type 3 laboratory-confirmed cases were reported with onset during 2000-2020. The highest WPV incidence rates per 100,000 population in Local Government Areas were 19.4, 12.0, and 11.3, all in 2006. Wild poliovirus cases were reported each year during 2000-2014; the endemic transmission went undetected throughout 2015 until the last cases in 2016. Ten events/milestones were highlighted, including insurgency in the northeast which led to a setback in 2016 with four cases from children previously trapped in security-compromised areas. Conclusion: Nigeria interrupted WPV transmission despite the challenges faced because of the emergency management approach, implementation of mass vaccination campaigns, the commitment of the government agencies, support from global polio partners, and special strategies deployed to conduct vaccination and surveillance in the security-compromised areas.

Is it time to switch to a formulation other than the live attenuated poliovirus vaccine to prevent poliomyelitis?

The polioviruses (PVs) are mainly transmitted by direct contact with an infected person through the fecal-oral route and respiratory secretions (or more rarely via contaminated water or food) and have a primary tropism for the gut. After their replication in the gut, in rare cases (far less than 1% of the infected individuals), PVs can spread to the central nervous system leading to flaccid paralysis, which can result in respiratory paralysis and death. By the middle of the 20th century, every year the wild polioviruses (WPVs) are supposed to have killed or paralyzed over half a million people. The introduction of the oral poliovirus vaccines (OPVs) through mass vaccination campaigns (combined with better application of hygiene measures), was a success story which enabled the World Health Organization (WHO) to set the global eradication of poliomyelitis as an objective. However this strategy of viral eradication has its limits as the majority of poliomyelitis cases today arise in individuals infected with circulating vaccine-derived polioviruses (cVDPVs) which regain pathogenicity following reversion or recombination. In recent years (between January 2018 and May 2023), the WHO recorded 8.8 times more cases of polio which were linked to the attenuated OPV vaccines (3,442 polio cases after reversion or recombination events) than cases linked to a WPV (390 cases). Recent knowledge of the evolution of RNA viruses and the exchange of genetic material among biological entities of the intestinal microbiota, call for a reassessment of the polio eradication vaccine strategies.

Enterovirus detection in different regions of Madagascar reveals a higher abundance of enteroviruses of species C in areas where several outbreaks of vaccine-derived polioviruses occurred.

BACKGROUND: Poliomyelitis outbreaks due to pathogenic vaccine-derived polioviruses (VDPVs) are threatening and complicating the global polio eradication initiative. Most of these VDPVs are genetic recombinants with non-polio enteroviruses (NPEVs) of species C. Little is known about factors favoring this genetic macroevolution process. Since 2001, Madagascar has experienced several outbreaks of poliomyelitis due to VDPVs, and most of VDPVs were isolated in the south of the island. The current study explored some of the viral factors that can promote and explain the emergence of recombinant VDPVs in Madagascar. METHODS: Between May to August 2011, we collected stools from healthy children living in two southern and two northern regions of Madagascar. Virus isolation was done in RD, HEp-2c, and L20B cell lines, and enteroviruses were detected using a wide-spectrum 5'-untranslated region RT-PCR assay. NPEVs were then sequenced for the VP1 gene used for viral genotyping. RESULTS: Overall, we collected 1309 stools, of which 351 NPEVs (26.8%) were identified. Sequencing revealed 33 types of viruses belonging to three different species: Enterovirus A (8.5%), Enterovirus B (EV-B, 40.2%), and Enterovirus C (EV-C, 51.3%). EV-C species included coxsackievirus A13, A17, and A20 previously described as putative recombination partners for poliovirus vaccine strains. Interestingly, the isolation rate was higher among stools originating from the South (30.3% vs. 23.6%, p-value = 0.009). EV-C were predominant in southern sites (65.7%) while EV-B predominated in northern sites (54.9%). The factors that explain the relative abundance of EV-C in the South are still unknown. CONCLUSIONS: Whatever its causes, the relative abundance of EV-C in the South of Madagascar may have promoted the infections of children by EV-C, including the PV vaccine strains, and have favored the recombination events between PVs and NPEVs in co-infected children, thus leading to the recurrent emergence of recombinant VDPVs in this region of Madagascar.

Production and Characterisation of Stabilised PV-3 Virus-like Particles Using Pichia pastoris.

Following the success of global vaccination programmes using the live-attenuated oral and inactivated poliovirus vaccines (OPV and IPV), wild poliovirus (PV) is now only endemic in Afghanistan and Pakistan. However, the continued use of these vaccines poses potential risks to the eradication of PV. The production of recombinant PV virus-like particles (VLPs), which lack the viral genome offer great potential as next-generation vaccines for the post-polio world. We have previously reported production of PV VLPs using Pichia pastoris, however, these VLPs were in the non-native conformation (C Ag), which would not produce effective protection against PV. Here, we build on this work and show that it is possible to produce wt PV-3 and thermally stabilised PV-3 (referred to as PV-3 SC8) VLPs in the native conformation (D Ag) using Pichia pastoris. We show that the PV-3 SC8 VLPs provide a much-improved D:C antigen ratio as compared to wt PV-3, whilst exhibiting greater thermostability than the current IPV vaccine. Finally, we determine the cryo-EM structure of the yeast-derived PV-3 SC8 VLPs and compare this to previously published PV-3 D Ag structures, highlighting the similarities between these recombinantly expressed VLPs and the infectious virus, further emphasising their potential as a next-generation vaccine candidate for PV.

Estratégia de Erradicação da Poliomielite 2022-2026: Cumprimento de uma Promessa

A promessa de um mundo livre da poliomielite tem sido a força motriz por trás da Iniciativa Global de Erradicação da Poliomielite (GPEI), contribuindo para ganhos fundamentais na saúde nas últimas três décadas. De fato, antes da doença do coronavírus (COVID-19), a erradicação da poliomielite significava para muitos algo que o mundo poderia alcançar unindo-se para proteger e promover a saúde de todas as crianças. Ao longo da última década, a Iniciativa Global de Erradicação da Poliomielite (GPEI) fez progressos constantes no caminho para a erradicação. Os poliovírus selvagens tipos 2 e 3 (WPV2 e WPV3) foram declarados erradicados em 2015 e 2019, respectivamente; a Região da Organização Mundial da Saúde (OMS) do Sudeste Asiático foi declarada livre de poliovírus em 2014; e, mais recentemente, a Região Africana da OMS foi certificada como livre de poliovírus selvagem (WPV) em agosto de 2020. No entanto, os passos finais para a erradicação provaram ser os mais difíceis. A Estratégia de Erradicação da Poliomielite 2022-2026 compreende um amplo conjunto de ações a fim de posicionar a GPEI para cumprir uma promessa que uniu o mundo em um compromisso coletivo de erradicação da poliomielite. Essas ações, muitas das quais já estavam em andamento em 2021, fortalecerão e capacitarão a GPEI para enfrentar os problemas, alcançar e manter um mundo livre da poliomielite.

Vacina Mais enfatiza importância da vacinação contra poliomielite no Brasil em novas peças de campanha

A Campanha Vacina Mais disponibilizou um novo pacote de peças de comunicação que abordam a importância da vacinação contra a poliomielite, também conhecida como paralisia infantil.

Procedimentos Operacionais Padrão: Resposta a um Evento ou Surto de Poliovírus - março 2022

O objetivo desses procedimentos operacionais padrão (POPs) é oferecer orientação a qualquer país que detecte qualquer tipo de surto ou evento de poliovírus, para responder de maneira oportuna e efetiva, com o objetivo específico de interromper os surtos de poliomielite dentro de 120 dias (quatro meses). Este guia se destina a governos nacionais e tomadores de decisão de saúde pública que coordenam respostas a eventos e surtos de poliovírus e seus parceiros globais, regionais e nacionais. Essa versão dos POPs se baseia nas versões anteriores desenvolvidas desde 2015 e leva em consideração os principais desenvolvimentos, lições aprendidas e disponibilidade de novas ferramentas desde a publicação da última versão, em março de 2020. O desenvolvimento desses POPs depende de evidências científicas disponíveis e consenso de especialistas, mantendo-se fundamentado em realidades operacionais e no contexto de diminuição da imunidade global ao poliovírus tipo 2. Os aspectos fundamentais dos POPs resultam de ampla consulta com grupos consultivos de especialistas, incluindo o Grupo de Especialistas Consultivos Estratégicos (SAGE) da Organização Mundial da Saúde (OMS) sobre imunização, com endosso pelos grupos técnicos e de gestão relevantes da GPEI. Esses POPs não incluem resposta ao WPV1 devido à transmissão local em um contexto endêmico, orientações operacionais em nível de campo nem ferramentas para planejamento de atividades de imunização suplementar (SIAs) de alta qualidade ou métodos detalhados para vigilância aprimorada.

Understanding the reasons for refusal of polio vaccine by families in Quetta Block, Pakistan.

Background: Global polio eradication is a goal yet to be achieved in countries like Pakistan. In recent years, the Polio Eradication Initiative has been making steady progress with good campaign coverage and low numbers of polio cases. However, in 2019 Pakistan reported 146 cases compared to 12 in 2018. A major factor cited for this regression was a surge in vaccine refusals by parents and caretakers. Aims: To assess the reasons for the refusal of polio vaccination in Quetta Block, Balochistan. Methods: The study was conducted using data acquired from 2 polio vaccination campaigns over 3 months in 2019. The data were collected in Quetta Block, a highly endemic zone having continuous transmission of the polio virus over several years. The data were analysed using the statistical software, SPSS, version 20. We used descriptive statistics to demonstrate the characteristics of the study population. Categorical variables were measured as frequencies and percentages. Results: Refusal rates were almost 8.6% for the polio campaign of April and 8.1% for June 2019. Misconceptions about vaccines made up 56.4% of reasons for refusals, followed by religion 16%. Conclusion: Misconceptions about the vaccine are the main driving force behind vaccine refusals in the study setting. Efficient strategies are required to address misconceptions in this red zone of poliovirus transmission in Balochistan.

Pólio: baixa cobertura vacinal e o risco iminente de novas infecções / Polio: low vaccination coverage and the imminent risk of new infections

A poliomielite, comumente chamada de pólio ou paralisia infantil, é uma doença viral altamente infecciosa que afeta principalmente crianças menores de 5 anos de idade. O vírus é transmitido de pessoa para pessoa, disseminado principalmente pela via fecal-oral ou, menos frequentemente, por fômites (água ou alimentos contaminados); sendo que o agente etiológico pode se espalhar rapidamente em áreas cujos sistemas de higiene e saneamento são precários. Também pode haver transmissão por meio de gotículas de secreções da garganta durante a fala, tosse ou espirro ( WHO, 20 22 a ; SBIm, 2022)

Polio, commonly called polio or infantile paralysis, is a highly infectious viral disease that primarily affects children under 5 years of age. The virus is transmitted from person to person, spread mainly by the fecal-oral route or, less frequently, by fomites (contaminated water or food); being that the agent etiologic disease can spread rapidly in areas where hygiene and sanitation systems are precarious. There may also be transmission through droplets of secretions from the throat during speech, coughing or sneezing (WHO, 20 22 a ; SBIm, 2022)