Evolution of global polio eradication strategies: targets, vaccines, and supplemental immunization activities (SIAs).

BACKGROUND: Despite multiple revisions of targets and timelines in polio eradication plans since 1988, including changes in supplemental immunization activities (SIAs) that increase immunity above routine immunization (RI) coverage, poliovirus transmission continues as of 2024. METHODS: We reviewed polio eradication plans and Global Polio Eradication Initiative (GPEI) annual reports and budgets to characterize key phases of polio eradication, the evolution of poliovirus vaccines, and the role of SIAs. We used polio epidemiology to provide context for successes and failures and updated prior modeling to show the contribution of SIAs in achieving and maintaining low polio incidence compared to expected incidence for the counterfactual of RI only. RESULTS: We identified multiple phases of polio eradication that included shifts in targets and timelines and the introduction of different poliovirus vaccines, which influenced polio epidemiology. Notable shifts occurred in GPEI investments in SIAs since 2001, particularly since 2016. Modeling results suggest that SIAs play(ed) a key role in increasing (and maintaining) high population immunity to levels required to eradicate poliovirus transmission globally. CONCLUSIONS: Shifts in polio eradication strategy and poliovirus vaccine usage in SIAs provide important context for understanding polio epidemiology, delayed achievement of polio eradication milestones, and complexity of the polio endgame.

Campanhas Multivacinação e Poliomielite 2020

VT publicitário de vacinação Sesa 2020 para campanhas de Multivacinação e Poliomielite.

Webpalestra: Campanha de Vacinação contra a Poliomielite e Multivacinação

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Coletiva de imprensa: anúncios do Governo SP - 02/10/2020

O Governador João Doria anunciou nesta sexta-feira (2) o início da Campanha de Vacinação de Poliomielite e Multivacinação a partir da próxima segunda-feira (5). O objetivo é atualizar a carteirinha de vacinação de crianças e adolescentes entre 0 e 14 anos de idade, reforçando a proteção contra paralisia infantil (polio) nos menores de 5 anos. “É de extrema importância que todos estejam atentos à imunização e façam uso desta facilidade que o Governo do Estado, através da Secretaria de Saúde e das Secretarias Municipais de Saúde, oferecem gratuitamente à população de São Paulo. A vacinação é o meio mais eficaz e seguro de proteção contra doenças graves”, afirmou Doria. Para garantir a prevenção contra a poliomielite, pais ou responsáveis por crianças entre 1 ano a menores de 5 anos deverão levar os pequenos para receber a “gotinha” (vacina oral, VOP). A meta é alcançar cobertura vacinal de 95% de um total de 2,2 milhões de crianças (ou seja, pelo menos 2,1 milhões). A revacinação contribui com a redução do risco de reintrodução do vírus no Brasil – hoje, há circulação no Afeganistão e Paquistão. Simultaneamente, a campanha de multivacinação será focada na atualização de carteiras vacinais de crianças e adolescentes de 0 a 14 anos. A finalidade é que pessoas nessa faixa etária recebam doses de vacinas importantes e que podem estar pendentes, garantindo assim a devida proteção contra vírus que circulam no território. “Estas campanhas foram criadas justamente para incentivar a ida aos postos de saúde e, assim, garantir a proteção adequada”, afirma o Secretário de Estado da Saúde, Jean Gorinchteyn. Os pais ou responsáveis devem levar as crianças a um dos 5 mil postos de saúde localizados nos municípios de SP com a carteira de vacinação em mãos para que um profissional avalie quais doses precisarão ser aplicadas, tanto para eventual situação de atraso, falta ou necessidade de reforço. A medida contribui para melhorar as coberturas vacinais, que têm oscilado nos últimos anos. No total, serão oferecidas 14 tipos de vacinas que protegem contra cerca de 20 doenças: BCG (tuberculose); rotavírus (diarreia); poliomelite oral e intramuscular (paralisia infantil); pentavalente (difteria, tétano, coqueluche, hepatite B, Haemophilus influenza tipo b – Hib); pneumocócica; meningocócica; DTP; tríplice viral (sarampo, caxumba e rubéola); HPV (previne o câncer de colo de útero e verrugas genitais); além das vacinas contra febre amarela, varicela e hepatite A. Além disso, neste ano, também passou a integrar o SUS uma nova vacina, já inserida na campanha: Meningo ACWY, que protege contra meningite e infecções generalizadas, causadas pela bactéria meningococo dos tipos A, C, W e Y. Somando todos os tipos de vacinas, são mais de 5,2 milhões distribuídas nos postos do estado para aplicação na população-alvo. Serão mobilizados cerca de 30 mil profissionais de saúde até o dia 30 de outubro, prazo definido pelo Ministério da Saúde na campanha nacional. O Dia de Mobilização (“Dia D”) será 17 de outubro, com postos abertos no sábado. “A imunização correta garante a proteção contra complicações provocadas por diferentes tipos de vírus e, consequentemente, reduz casos e mortes. As campanhas contribuem para erradicação e para a eliminação do risco de reintrodução de doenças no território”, explica a diretora de Imunização da Secretaria, Núbia Araújo. A tabela completa com relação das vacinas, faixas etárias previstas para receber as doses e dados de cobertura está disponível no link: https://www.saopaulo.sp.gov.br/wp-content/uploads/2020/10/tabelavacinacao.pdf. No geral, são indicadas coberturas vacinais de 90% e 95% para proteção efetiva da população, mas tais índices não têm sido atingidos devido à baixa adesão. Alguns exemplos de cobertura inferior registrada em 2019, conforme dados disponíveis em sistema do PNI (Programa Nacional de Imunizações) são: menincoccócica C (87,28%), pentavalente (71,77%), poliomielite (86,16%), e tríplice viral (91,37% na primeira dose e 82% na segunda dose). Os dados preliminares de 2020, até agosto, indicam a importância de melhorar os índices. “Temos acompanhado os dados da cobertura vacinal em todo o estado e estamos em alerta com os baixos alcances. A Campanha de Multivacinação será um auxílio para aumentarmos a proteção e minimizarmos as chances de que as doenças retornem. Nosso objetivo é que o Estado de São Paulo tenha a maior cobertura vacinal entre os estados do país”, ressalta a coordenadora do Programa Estadual de Vacinação, Helena Sato.

Assessment of a poly-epitope candidate vaccine against Hepatitis B, C, and poliovirus in interaction with monocyte-derived dendritic cells: An ex-vivo study.

Design and application of epitope-based polyvalent vaccines have recently garnered attention as an efficient alternative for conventional vaccines. We previously have reported the in silico design of HHP antigen which encompasses the immune-dominant epitopes of Hepatitis B surface antigen (HBsAg), Hepatitis C core protein (HCVcp) and Poliovirus viral proteins (VPs). It has been shown that the HHP has desirable conformation to expose the epitopes, high antigenicity and other desired physicochemical and immunological properties. To confirm the accuracy of these predictions, the ex-vivo immunogenicity of the HHP was assessed. The HHP gene was chemically synthesized in pET28a and expressed in E. coli (BL21). The expressed protein was purified and its immunological potency was evaluated on dendritic cells (DCs) as antigen presenting cells (APCs). Functional analysis was assessed in co-cultivation of autologous T-cells with matured DCs (mDCs). T-cell activation, proliferation and cytokines secretion were evaluated using flowcytometry and ELISA methods. Our results indicated that the HHP could induce the DC maturation. The mDCs were able to trigger T-cell activation and proliferation. In silico design and ex-vivo confirmation of immunological potential could pave the way to introduce efficient immunogens for further analysis. The ability of HHP in DC maturation and T-cell activation makes it an amenable vaccine candidate for further in-vivo studies.

Universal ELISA for quantification of D-antigen in inactivated poliovirus vaccines.

To address the biosafety and biosecurity concerns related to the manufacture of inactivated polio vaccine (IPV), several manufacturers started producing it from attenuated Sabin strains. Slight immunological differences between wild and attenuated strains create a challenge for testing IPV potency, which is defined as the content of protective D-antigen determined in an ELISA test. Some ELISA reagents selected for testing conventional IPV made from wild strains (cIPV) may not be suitable for testing Sabin IPV (sIPV). This paper describes an ELISA procedure using human monoclonal antibodies selected to capture equally well both wild and attenuated strains of poliovirus. A unique monoclonal antibody neutralizing all three serotypes of poliovirus was used as the detection antibody. The method was shown to detect only D-antigen of both conventional and Sabin IPV and to be strictly serotype-specific. The method is highly sensitive and robust and produces linear results in a wide range of concentrations. We have also found that reference standards used for measuring potency of cIPV and sIPV must be made from respective vaccines. This makes it impossible to cross-calibrate potency reagents made from heterologous vaccine and requires the establishment of a new unit to measure potency of sIPV that is different from conventional D-antigen unit.

A comparative assessment of cold chain management using the outbreak of circulating vaccine-derived polio virus type 2 as a surrogate marker in Oyo State, Nigeria-2019.

INTRODUCTION: inspite of the demonstrable evidence of the preventive and protective ability of vaccines to reduce the outbreak of vaccine-preventable diseases, there are still some significant disease outbreaks recorded in our communities. In some settings, these outbreaks have been linked with poor vaccine management. Therefore, this study was conducted to compare the cold chain practices in Oyo State, Nigeria. METHODS: we conducted a cross-sectional survey among health workers in the local government areas of Oyo State between October and November 2019. Using purposive sampling, we recruited all the 84 routine immunization focal persons for the study. A self-administered questionnaire was used to collect data on cold chain management. Data were analyzed using SPSS version 24 and bivariate analysis was done using Chi-square. Statistical significance was set at p < 0.05. RESULTS: the mean age of the respondents was 46.4 ± 6.7 years. Most prevalent cadre in the rural facilities was health assistants (87.5%) while Community Extension Health Workers (54.8%) were prevalent in the urban (p = 0.002). The proportion of respondents with adequate cold chain equipment was significantly higher in the urban compared with the rural area. The cold boxes were the only adequate cold chain equipment found in the rural health facilities compared with the urban (p = 0.036). CONCLUSION: there was a low proportion of qualified health workers and inadequate cold chain equipment in the rural area compared with the urban facilities. Engagement of skilled health workers and supply of the cold chain equipment are recommended.

[Update on vaccines: 2018 recommendations]. / Actualización sobre vacunas: recomendaciones de 2018.

Beginning in 1974, the date on which the Expanded Program on Immunization was established in the Americas, the number of deaths and disabilities due to certain infectious diseases decreased considerably thanks to universally applied vaccines. A program that initially included four vaccines that protected against six diseases (tuberculosis, diphtheria, pertussis, tetanus, polio and measles) was consolidated, over the years, by incorporating new vaccines and significantly raising coverage rates. The Sociedad Argentina de Pediatría (Argentine Society of Pediatrics), as a leader of opinion, played a leading role in the incorporation of new vaccines, currently reaching one of the most complete vaccination calendars in the world, which improves the levels of inequality and inequity in public health. Taking into account the significant role of the pediatrician in decision-making, the National Committee of Infectious Diseases, together with the Subsidiary Committees, prepared a document on updates and recommendations for 2018 on Polio, Rotavirus, Pneumococcus, Meningococcus, Human Papillomavirus, Chickenpox, Flu, Dengue vaccines and Whooping Cough.

A partir del año 1974, cuando se estableció el Programa Ampliado de Inmunizaciones en las Américas, la cantidad de muertes y discapacidades por enfermedades infecciosas disminuyó de manera considerable gracias a las vacunas aplicadas. Inicialmente, se incluyeron cuatro vacunas que protegían contra seis enfermedades (tuberculosis, difteria, coqueluche, tétanos, polio y sarampión), y, a través de los años, al incorporar nuevas vacunas, aumentaron considerablemente las tasas de cobertura. La Sociedad Argentina de Pediatría tuvo un rol destacado en la incorporación de nuevas vacunas y, en la actualidad, hay uno de los calendarios de vacunación más completos del mundo, lo que permite mejorar los niveles de desigualdad e inequidad en salud pública. Teniendo en cuenta el rol que tiene el pediatra en la toma de decisiones, el Comité Nacional de Infectología, junto con comités de filiales, elaboró un documento sobre actualizaciones y recomendaciones de 2018 acerca de polio, rotavirus, neumococo, meningococo, virus del papiloma humano, varicela, gripe, dengue y coqueluche.

High coverage of polio immunization program in refugees resettling in Denmark. A cross-sectional study of polio serology in newly arrived refugees.

Objectives: Wild poliovirus (WPV) infection has been eliminated in Europe through mass immunization. Resettling refugees may lack immunity and importing WPV through refugees continues to cause concerns.Method: We performed a cross-sectional study to establish the prevalence of poliovirus immunity in children and adult refugees resettling in Aarhus, Denmark. Immunity was evaluated by antibody response for serotypes 1, 2, and 3.Results: The participants in this study counted a total of 475 children and adult refugees aged between 6 months and 76 years and 59% were males. The survey was conducted between 2014 and 2016. Among the refugees, 72% were from Syria, and the rest from Eritrea, Congo, Lebanon, Somalia, Afghanistan, Iran, Iraq, Ethiopia, and Columbia. In the cohort, 27 lacked antibodies against a least one serotype. None of the participants lacked antibodies against all three polio types. Originating from The Horn of Africa, age between 20 and 30 and male gender was associated with lack of immunity.Conclusion: The study found a complete WPV immunity in 94% of recently resettled refugees in Denmark. This study demonstrates a high coverage of the polio immunization program. However, ensuring poliovirus immunity among refugees remains a priority until polio has been eradicated worldwide.

Vaccine-Derived Poliovirus Infection among Patients with Primary Immunodeficiency and Effect of Patient Screening on Disease Outcomes, Iran.

Patients with immunodeficiency-associated vaccine-derived poliovirus (iVDPV) are potential poliovirus reservoirs in the posteradication era that might reintroduce polioviruses into the community. We update the iVDPV registry in Iran by reporting 9 new patients. In addition to national acute flaccid paralysis surveillance, cases were identified by screening nonparalyzed primary immunodeficiency (PID) patients. Overall, 23 iVDPV patients have been identified since 1995. Seven patients (30%) never had paralysis. Poliovirus screening accelerated the iVDPV detection rate in Iran after 2014.The iVDPV infection rate among nonparalyzed patients with adaptive PID was 3.1% (7/224), several folds higher than previous estimates. Severe combined immunodeficiency patients had the highest risk for asymptomatic infection (28.6%) compared with other PIDs. iVDPV2 emergence has decreased after the switch from trivalent to bivalent oral poliovirus vaccine in 2016. However, emergence of iVDPV1 and iVDPV3 continued. Poliovirus screening in PID patients is an essential step in the endgame of polio eradication.

Identification of genes and pathways in human antigen-presenting cell subsets in response to polio vaccine by bioinformatical analysis.

BACKGROUND: Polio eradication has been achieved in the world except for three countries due to the widespread use of the inactivated poliovirus vaccine (IPV) and the live-attenuated oral poliovirus vaccine. Following polio eradication, the IPV would be the only polio vaccine available. However, the mechanisms of the interactions between IPV and human antigen-presenting cells (APCs) remain largely unclear. METHODS: To investigate the involvement of the IPV in human monocytes, we downloaded the gene chip GSE44721 from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the GEO2R analysis tool. Functional and pathway enrichment analyses were performed for DEGs using the Metascape database. DEG-associated protein-protein-interactions (PPIs) were established by the Search Tool for the Retrieval of Interacting Genes website and visualized by Cytoscape. RESULTS: There were 240 DEGs (51 upregulated and 189 downregulated genes) identified from the GSE44721 data set, and they were significantly enriched in several biological processes, including antigen processing and presentation of lipid antigen via MHC class Ib, adaptive immune response, and response to interferon-gamma. One hundred thirty-six nodes were screened from the DEG PPI network. There were six significant hub proteins (WDR36, MRTO4, RPF2, PPAN, CD40, and BMS1) that regulated the IPV in human monocytes. CONCLUSIONS: In summary, using bioinformatical analysis, we have information for the immunization activated by the IPV in monocytes. Moreover, hormones and cytokines regulate the activation of APCs.

Completeness and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and polio vaccines in young children with chronic health conditions: A systematic review.

OBJECTIVE: To systematically review literature on uptake and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and/or polio-containing vaccines ininfants who were born preterm, with a low birth weight, and/or with chronic health conditions that were diagnosed within the first 6 months of life. METHODS: Using a standardized search strategy developed by a medical librarian, records were extracted from MEDLINE, Embase, Database of Abstracts of Reviews of Effects, and CINAHL up to May 8, 2018. RESULTS: Out of the 1997 records that were screened, we identified 21 studies that met inclusion criteria. Eleven studies assessed vaccine coverage and/or timeliness in preterm infants, 6 in low birth weight infants, and 7 in children with chronic health conditions. Estimates of coverage in these populations were highly variable, ranging from 40% to 100% across the vaccines and population groups. CONCLUSIONS: There is a lack of studies reporting coverage and timeliness of routine immunizations in special populations of children. POLICY IMPLICATIONS: Our review suggests a need for improved surveillance of immunization status in special populations of infants, as wellas aneed for standardization of reporting practices.

Mucosal Immunity: The Forgotten Arm of the Immune System.

The 2017 Stanley A. Plotkin Lecture in Vaccinology was delivered by Professor Peter F. Wright at the Pediatric Academic Societies Annual Meeting in San Francisco, California, in May 2017. The presentation provided an overview of the mucosal immune system as it applies to vaccinology. Specifically, Professor Wright's lecture highlighted the remarkable opportunities for mucosal immunity research afforded by having both topically administered live vaccines and systemically administered inactivated vaccines available for the same pathogen. Using influenza and poliovirus case studies, Professor Wright described the use of live attenuated vaccines for human challenges and discussed how recent technological advancements in immunological assays have ushered in a new era for investigating the correlates of immune protection against wild-type infections at mucosal sites.

Breaking the Last Chains of Poliovirus Transmission: Progress and Challenges in Global Polio Eradication.

Since the launch of the Global Polio Eradication Initiative (GPEI), paralytic cases associated with wild poliovirus (WPV) have fallen from ∼350,000 in 1988 to 22 in 2017. WPV type 2 (WPV2) was last detected in 1999, WPV3 in 2012, and WPV1 appeared to be localized to Pakistan and Afghanistan in 2017. Through continuous refinement, the GPEI has overcome operational and biological challenges far more complex and daunting than originally envisioned. Operational challenges had led to sustained WPV endemicity in core reservoirs and widespread dissemination to polio-free countries. The biological challenges derive from intrinsic limitations to the oral poliovirus vaccine: ( a) reduced immunogenicity in high-risk settings and ( b) genetic instability, leading to repeated outbreaks of circulating vaccine-derived polioviruses and prolonged infections in individuals with primary immunodeficiencies. As polio eradication enters its multifaceted endgame, the GPEI, with its technical, operational, and social innovations, stands as the preeminent model for control of vaccine-preventable diseases worldwide.

Newcastle Disease Virus-Based Vectored Vaccine against Poliomyelitis.

The poliovirus eradication initiative has spawned global immunization infrastructure and dramatically decreased the prevalence of the disease, yet the original virus eradication goal has not been met. The suboptimal properties of the existing vaccines are among the major reasons why the program has repeatedly missed eradication deadlines. Oral live poliovirus vaccine (OPV), while affordable and effective, occasionally causes the disease in the primary recipients, and the attenuated viruses rapidly regain virulence and can cause poliomyelitis outbreaks. Inactivated poliovirus vaccine (IPV) is safe but expensive and does not induce the mucosal immunity necessary to interrupt virus transmission. While the need for a better vaccine is widely recognized, current efforts are focused largely on improvements to the OPV or IPV, which are still beset by the fundamental drawbacks of the original products. Here we demonstrate a different design of an antipoliovirus vaccine based on in situ production of virus-like particles (VLPs). The poliovirus capsid protein precursor, together with a protease required for its processing, are expressed from a Newcastle disease virus (NDV) vector, a negative-strand RNA virus with mucosal tropism. In this system, poliovirus VLPs are produced in the cells of vaccine recipients and are presented to their immune systems in the context of active replication of NDV, which serves as a natural adjuvant. Intranasal administration of the vectored vaccine to guinea pigs induced strong neutralizing systemic and mucosal antibody responses. Thus, the vectored poliovirus vaccine combines the affordability and efficiency of a live vaccine with absolute safety, since no full-length poliovirus genome is present at any stage of the vaccine life cycle.IMPORTANCE A new, safe, and effective vaccine against poliovirus is urgently needed not only to complete the eradication of the virus but also to be used in the future to prevent possible virus reemergence in a postpolio world. Currently, new formulations of the oral vaccine, as well as improvements to the inactivated vaccine, are being explored. In this study, we designed a viral vector with mucosal tropism that expresses poliovirus capsid proteins. Thus, poliovirus VLPs are produced in vivo, in the cells of a vaccine recipient, and are presented to the immune system in the context of vector virus replication, stimulating the development of systemic and mucosal immune responses. Such an approach allows the development of an affordable and safe vaccine that does not rely on the full-length poliovirus genome at any stage.

Seroprevalence of antibodies against the three serotypes of poliovirus and IPV vaccine response in adult solid organ transplant candidates.

OBJECTIVES: To assess the prevalence of protective antibody titers to polioviruses in adults candidates for solid organ transplant (SOT), and to assess the immunogenic response to inactivated polio vaccine in this population. METHODS: The study included SOT candidates referred to Immunization Reference Centre of Evandro Chagas National Institute of Infectious Diseases from March 2013 to January 2016. It was conducted in 2 phases. The first one, a cross-sectional seroprevalence study, followed by an uncontrolled analysis of vaccine response among patients without protective antibody titers at baseline. Antibody titers to poliomyelitis were determined by microneutralization assay. RESULTS: Among 206 SOT candidates included, 156 (76%) had protective antibody titers to all poliovirus serotypes (95% CI: 70-81%). Proven history of oral vaccination in childhood was not associated with higher seroprevalence of protective antibody. In 97% of individuals without protective antibody titers at baseline, there was adequate vaccine response with one dose of inactivated polio vaccine. CONCLUSIONS: A relevant proportion of adult candidates for SOT does not have protective titers of antibodies to one or more poliovirus serotype. One dose of inactivated vaccine elicited protective antibody titers in 97% of these subjects and should be routinely prescribed prior to SOT.

Immunity levels to poliovirus in Lao children and adults before the vaccine-derived poliovirus outbreak: A retrospective study.

In 2015, several provinces in Lao People's Democratic Republic (Lao PDR) experienced a vaccine-derived poliovirus outbreak. This survey was conducted (i) to evaluate the vaccination coverage in different settings and cohorts using the seroprevalence of anti-poliovirus (PV) antibodies as a surrogate measure, and (ii) to explore the usefulness of an ELISA in a country with limited resources and a specific epidemiological setting. IgG antibodies were assessed by ELISA in Lao children (n = 1216) and adults (n = 1228), including blood donors and health care workers. Protective antibody titers against the 3 vaccine serotypes were determined by microneutralization (VNT) in a subset of participants. More than 92% of the children had anti-poliovirus antibodies, regardless of nutritional status or access to health care, highlighting the success of the vaccination outreach activities in the country. In contrast, anti-poliovirus seroprevalence reached only 81.7% in blood donors and 71.9% in health care workers. Participants born before the introduction of poliovirus vaccination in Lao PDR were considerably less likely to be seropositive. These findings align with the epidemiology of the outbreak. Neutralizing antibodies against at least one of the 3 poliovirus serotypes were detected in all children (99/99) and 93/99 had antibodies against all serotypes. Similarly, all health care workers had neutralizing antibodies against at least one and 92/99 against all serotypes. The comparison of both assays shows an acceptable underestimation of vaccine coverage in children by ELISA, but a low sensitivity of the ELISA in the adults. We show that the ELISA is a reasonable alternative to the VNT in particular in vaccinated children, that an improved version should be serotype specific, and that negativity thresholds should be revisited for optimal sensitivity and specificity. Thus, polio-free countries with an uncertain vaccination coverage and limited laboratory capacity, that are at risk of vaccine-derived poliovirus outbreaks or of re-importation of wild poliovirus may benefit from an improved ELISA for cohort studies to evaluate their immunization program in children.