Enhanced Assessment of Cross-Reactive Antigenic Determinants within the Spike Protein.

Despite successful vaccination efforts, the emergence of new SARS-CoV-2 variants poses ongoing challenges to control COVID-19. Understanding humoral responses regarding SARS-CoV-2 infections and their impact is crucial for developing future vaccines that are effective worldwide. Here, we identified 41 immunodominant linear B-cell epitopes in its spike glycoprotein with an SPOT synthesis peptide array probed with a pool of serum from hospitalized COVID-19 patients. The bioinformatics showed a restricted set of epitopes unique to SARS-CoV-2 compared to other coronavirus family members. Potential crosstalk was also detected with Dengue virus (DENV), which was confirmed by screening individuals infected with DENV before the COVID-19 pandemic in a commercial ELISA for anti-SARS-CoV-2 antibodies. A high-resolution evaluation of antibody reactivity against peptides representing epitopes in the spike protein identified ten sequences in the NTD, RBD, and S2 domains. Functionally, antibody-dependent enhancement (ADE) in SARS-CoV-2 infections of monocytes was observed in vitro with pre-pandemic Dengue-positive sera. A significant increase in viral load was measured compared to that of the controls, with no detectable neutralization or considerable cell death, suggesting its role in viral entry. Cross-reactivity against peptides from spike proteins was observed for the pre-pandemic sera. This study highlights the importance of identifying specific epitopes generated during the humoral response to a pathogenic infection to understand the potential interplay of previous and future infections on diseases and their impact on vaccinations and immunodiagnostics.

Humoral Immune Response to SARS-CoV-2 Spike Protein Receptor-Binding Motif Linear Epitopes.

The worldwide spread of SARS-CoV-2 has led to a significant economic and social burden on a global scale. Even though the pandemic has concluded, apprehension remains regarding the emergence of highly transmissible variants capable of evading immunity induced by either vaccination or prior infection. The success of viral penetration is due to the specific amino acid residues of the receptor-binding motif (RBM) involved in viral attachment. This region interacts with the cellular receptor ACE2, triggering a neutralizing antibody (nAb) response. In this study, we evaluated serum immunogenicity from individuals who received either a single dose or a combination of different vaccines against the original SARS-CoV-2 strain and a mutated linear RBM. Despite a modest antibody response to wild-type SARS-CoV-2 RBM, the Omicron variants exhibit four mutations in the RBM (S477N, T478K, E484A, and F486V) that result in even lower antibody titers. The primary immune responses observed were directed toward IgA and IgG. While nAbs typically target the RBD, our investigation has unveiled reduced seroreactivity within the RBD's crucial subregion, the RBM. This deficiency may have implications for the generation of protective nAbs. An evaluation of S1WT and S2WT RBM peptides binding to nAbs using microscale thermophoresis revealed a higher affinity (35 nM) for the S2WT sequence (GSTPCNGVEGFNCYF), which includes the FNCY patch. Our findings suggest that the linear RBM of SARS-CoV-2 is not an immunodominant region in vaccinated individuals. Comprehending the intricate dynamics of the humoral response, its interplay with viral evolution, and host genetics is crucial for formulating effective vaccination strategies, targeting not only SARS-CoV-2 but also anticipating potential future coronaviruses.

Mapping IgA Epitope and Cross-Reactivity between Severe Acute Respiratory Syndrome-Associated Coronavirus 2 and DENV.

BACKGROUND: The newly introduced COVID-19 vaccines have reduced disease severity and hospitalizations. However, they do not significantly prevent infection or transmission. In the same context, measuring IgM and IgG antibody levels is important, but it does not provide information about the status of the mucosal immune response. This article describes a comprehensive mapping of IgA epitopes of the S protein, its cross-reactivity, and the development of an ELISA-peptide assay. METHODS: IgA epitope mapping was conducted using SPOT synthesis and sera from RT-qPCR COVID-19-positive patients. Specific and cross-reacting epitopes were identified, and an evolutionary analysis from the early Wuhan strain to the Omicron variant was performed using bioinformatics tools and a microarray of peptides. The selected epitopes were chemically synthesized and evaluated using ELISA-IgA. RESULTS: A total of 40 IgA epitopes were identified with 23 in S1 and 17 in the S2 subunit. Among these, at least 23 epitopes showed cross-reactivity with DENV and other organisms and 24 showed cross-reactivity with other associated coronaviruses. Three MAP4 polypeptides were validated by ELISA, demonstrating a sensitivity of 90-99.96% and a specificity of 100%. Among the six IgA-RBD epitopes, only the SC/18 epitope of the Omicron variants (BA.2 and BA.2.12.1) presented a single IgA epitope. CONCLUSIONS: This research unveiled the IgA epitome of the S protein and identified many epitopes that exhibit cross-reactivity with DENV and other coronaviruses. The S protein of variants from Wuhan to Omicron retains many conserved IgA epitopes except for one epitope (#SCov/18). The cross-reactivity with DENV suggests limitations in using the whole S protein or the S1/S2/RBD segment for IgA serological diagnostic tests for COVID-19. The expression of these identified specific epitopes as diagnostic biomarkers could facilitate monitoring mucosal immunity to COVID-19, potentially leading to more accurate diagnoses and alternative mucosal vaccines.

Relevance of national, regional and global virome projects on pandemics prediction, prevention, and control: a social network analysis of GVP-citing articles

BACKGROUND The Global Virome Project (GVP) was proposed in 2018 as an evolution of the USAID PREDICT project and was presented as a "collaborative scientific initiative to discover zoonotic viral threats and stop future pandemics". The immediate response was mixed, with public health and scientific communities representatives showing skepticism, if not direct opposition. OBJECTIVES The economic, social, and health consequences of the coronavirus disease 2019 (COVID-19) pandemic demonstrated how unprepared the world was in the face of new pandemics. This paper analyses the impact of the GVP on the scientific and public health communities. METHODS Published scientific articles that cited the two 2018 seminal publications proposing the project were analysed using social network analysis methods. FINDINGS Encompassing the periods before and after the onset of the Covid-19 pandemic, the results indicate that (i) the concepts of the GVP have received more support than opposition in the scientific literature; (ii) its foundations should be updated to address the specific criticisms. MAIN CONCLUSIONS Shifting focus to national virome projects can provide tangible, regional benefits that can positively contribute towards a consensus on achieving a high level of preparedness for the ever-present possibility of the following global viral pandemic.

Significance of a neglected tropical disease: lessons from a paradigmatic case of 'success in translation'

In a previous publication, I stressed the fundamental importance of research for improving health using as an example the control of Chagas disease in the Americas.(1) For that purpose, I analysed the major scientific breakthroughs and public health events from the 1909 discovery of Chagas disease and its causative pathogen, Trypanosoma cruzi, by Carlos Chagas,(2) through the successful control of its transmission by insect vectors in large regions of the Southern Cone countries in the 90s.(3) In the twenty years since that publication, Brazil and Latin American countries had to cope with a number of serious public health threats, old and new: (i) recrudescence of well-known diseases, such as dengue and yellow fever; (ii) emergence of viral diseases that had been restricted to other continents (Zika, Chikungunya); (iii) new epidemics (H1N1) or (iv) pandemics (COVID-19). Are there still some lessons from that success story against a neglected disease of the 90s that would be relevant today in the context of these recent challenges?

Why do we still have not a vaccine against Chagas disease?

This review does not intend to convey detailed experimental or bibliographic data. Instead, it expresses the informal authors' personal views on topics that range from basic research on antigens and experimental models for Trypanosoma cruzi infection to vaccine prospects and vaccine production. The review also includes general aspects of Chagas' disease control and international and national policies on the subject. The authors contributed equally to the paper.

Política de Ciência, Tecnologia e Inovação em Saúde (CT& I/S): uma atualização para debate / Health Science, Technology and Innovation Policy (ST& I/H): an update for debate

Resumo O texto contém uma proposta atualizada de política de Ciência, Tecnologia e Inovação em Saúde no Brasil e a pertinência da atualização decorre do desastre nas atividades nesse terreno verificadas no país desde o início do atual governo federal em 2019, bem como dos desafios colocados pela emergência da pandemia COVID-19 desde 2020. Ele está organizado em cinco seções, a saber: Pesquisa em Saúde; Inovação Produtiva; Avaliação e Incorporação de Tecnologias em Saúde; Propriedade Intelectual em Saúde; Novos desafios colocados pela Pandemia. Os autores fazem parte do Comitê de Assessoramento em Ciência, Tecnologia e Inovação da Abrasco.

Abstract The text presents an updated proposal for a Health Science, Technology and Innovation Policy in Brazil, following the huge political turmoil in the country since 2019 and the COVID-19 pandemic since 2020. The proposal is presented in five sections: Scientific Research; Productive Innovation; Health Technology Assessment and Incorporation; Intellectual Property in Health; New challenges posed by the Pandemic. The authors take part in the Advisory Committee in Science, Technology and Innovation of the Brazilian Association of Collective Health.

Development, health, and international policy: the research and innovation dimension / Desarrollo, salud y política internacional: la dimensión de la investigación e innovación / Desenvolvimento, saúde e política internacional: a dimensão da pesquisa & inovação

Abstract: This text main objective is to discuss development and health from the perspective of the influence of global health governance, using as the tracer the dimension of research, development, and innovation policies in health, which relate to both important inputs for the health system, like drugs and medicines, vaccines, diagnostic reagents, and equipment, and innovative concepts and practices for the improvement of health systems and public health. The authors examine the two main macro-processes that influence development and health: the post-2015 Development Agenda and the process under way in the World Health Organization concerning research and development, intellectual property, and access to health inputs. The article concludes, first, that much remains to be done for the Agenda to truly represent a coherent and viable international political pact, and that the two macro-processes related to innovation in health need to be streamlined. But this requires democratization of participation by the main stakeholders - patients and the general population of the poorest countries - since this is the only way to overcome a "zero sum" result in the clash in the current debates among member State representatives.

Resumen: El objetivo central de este texto es discutir el desarrollo y la salud, desde la óptica de la influencia de la gobernanza de la salud global, utilizando como eje vertebrador la dimensión de las políticas de investigación, desarrollo e innovación en salud, que se refieren, por un lado, a insumos importantes para el sistema de salud -como fármacos y medicamentos, vacunas, reactivos para diagnóstico y equipamientos y, por otro, a conceptos y prácticas innovadoras, para el perfeccionamiento de los sistemas de salud y de la salud pública. Se examinan los dos principales macroprocesos que influencian el desarrollo y la salud: la Agenda del Desarrollo para el pos-2015 y el proceso sobre pesquisa y desarrollo, propiedad intelectual y acceso a insumos en salud, en curso dentro de la Organización Mundial de la Salud. Se concluye que se deben realizar muchos esfuerzos para que la referida agenda pueda representar un pacto político internacional coherente y viable, asimismo, los dos macroprocesos relacionados con la innovación en salud necesitan agilizarse, pero para esto es necesaria la democratización de la participación de los mayores interesados: los pacientes y, de manera general, la población de los países más pobres, pues sólo de esta forma será superada la "suma cero" donde se encuentra el embate entre los representantes de estados miembros en los debates actuales.

Resumo: O objetivo central deste texto é discutir desenvolvimento e saúde sob a ótica da influência da governança da saúde global, utilizando como traçador a dimensão das políticas de pesquisa, desenvolvimento e inovação em saúde, que se referem, de um lado, a insumos importantes para o sistema de saúde - como fármacos e medicamentos, vacinas, reativos para diagnóstico e equipamentos e, de outro, a conceitos e práticas inovadoras para o aperfeiçoamento dos sistemas de saúde e da saúde pública. Examina os dois principais macroprocessos que influenciam o desenvolvimento e a saúde: a Agenda do Desenvolvimento para o pós-2015 e o processo sobre pesquisa e desenvolvimento, propriedade intelectual e acesso a insumos em saúde em curso na Organização Mundial da Saúde. Conclui que muito há que ser feito para que a referida Agenda possa representar um pacto político internacional coerente e viável, e que os dois macroprocessos relacionados com a inovação em saúde precisam ser agilizados, mas para isto torna-se necessária a democratização da participação dos maiores interessados - os pacientes e, de modo geral, a população dos países mais pobres - pois só desta maneira será superada a "soma zero" em que se encontra o embate entre os representantes de Estados-membros nos debates atuais.

Proposta conceitual de telessaúde no modelo da pesquisa translacional / Proposal for a telehealth concept in the translational research model

OBJETIVO Rever relação conceitual entre telessaúde e pesquisa translacional. MÉTODOS Realizou-se busca bibliográfica sobre telessaúde nas bases Scopus, Cochrane BVS, Lilacs e Medline com a finalidade de encontrar experiências de telessaúde conjugadas com a discussão da pesquisa translacional em saúde. A busca recuperou oito estudos, que basearam a análise dos modelos das cinco etapas da pesquisa translacional com os múltiplos fluxos de política pública no contexto brasileiro da telessaúde. Esses modelos foram aplicados às atividades de telessaúde da Rede de Bancos de Leite Humano, na Rede Universitária de Telemedicina. RESULTADOS O ciclo da pesquisa translacional do leite humano coletado, armazenado e distribuído apresentou iniciativas de telessaúde integradas, tais como videoconferências, softwares e portais de síntese do conhecimento, compondo elementos de um ecossistema de informação, mediado por tecnologias da informação e comunicação no sistema de saúde. CONCLUSÕES A telessaúde deve ser compreendida como conjunto de atividades em rede mediadas por computação e que promovem a translação do conhecimento entre pesquisa e serviços de saúde. .

OBJECTIVE To review the conceptual relationship between telehealth and translational research. METHODS Bibliographical search on telehealth was conducted in the Scopus, Cochrane BVS, LILACS and MEDLINE databases to find experiences of telehealth in conjunction with discussion of translational research in health. The search retrieved eight studies based on analysis of models of the five stages of translational research and the multiple strands of public health policy in the context of telehealth in Brazil. The models were applied to telehealth activities concerning the Network of Human Milk Banks, in the Telemedicine University Network. RESULTS The translational research cycle of human milk collected, stored and distributed presents several integrated telehealth initiatives, such as video conferencing, and software and portals for synthesizing knowledge, composing elements of an information ecosystem, mediated by information and communication technologies in the health system. CONCLUSIONS Telehealth should be composed of a set of activities in a computer mediated network promoting the translation of knowledge between research and health services. .

Co-authorship network analysis: a powerful tool for strategic planning of research, development and capacity building programs on neglected diseases

Background: New approaches and tools were needed to support the strategic planning, implementation and management of a Program launched by the Brazilian Government to fund research, development and capacity building on neglected tropical diseases with strong focus on the North, Northeast and Center-West regions of the country where these diseases are prevalent. Methodology/Principal Findings: Based on demographic, epidemiological and burden of disease data, seven diseases were selected by the Ministry of Health as targets of the initiative. Publications on these diseases by Brazilian researchers were retrieved from international databases, analyzed and processed with text-mining tools in order to standardize author- and institution's names and addresses. Co-authorship networks based on these publications were assembled, visualized and analyzed with social network analysis software packages. Network visualization and analysis generated new information, allowing better design and strategic planning of the Program, enabling decision makers to characterize network components by area of work, identify institutions as well as authors playing major roles as central hubs or located at critical network cut-points and readily detect authors or institutions participating in large international scientific collaborating networks. Conclusions/Significance: Traditional criteria used to monitor and evaluate research proposals or R&D Programs, such as researchers' productivity and impact factor of scientific publications, are of limited value when addressing research areas of low productivity or involving institutions from endemic regions where human resources are limited. Network analysis was found to generate new and valuable information relevant to the strategic planning, implementation and monitoring of the Program. It afforded a more proactive role of the funding agencies in relation to public health and equity goals, to scientific capacity building objectives and a more consistent engagement of institutions and authors from endemic regions based on innovative criteria and parameters anchored on objective scientific data.

A pesquisa em saúde e os objetivos do milênio: desafios e oportunidades globais, soluções e políticas nacionais / Health research and the millennium development goals: global challenges and opportunities, national solutions and policies

Saúde, ciência e tecnologia são requisitos para o desenvolvimento econômico e social. Os Objetivos de Desenvolvimento do Milênio da ONU para 2015 representam um imenso desafio para os países em desenvolvimento. Esses países terão de organizar sistemas de pesquisa em saúde baseados em prioridades sanitárias e assegurar a incorporação dos resultados às políticas e ações de saúde. Avanços na área biomédica, em particular em genômica, abrem novas oportunidades, mas impõem desafios adicionais. O Brasil, possuidor de um forte parque industrial e uma vigorosa comunidade científica, tem capacidade para desenvolver um sistema de pesquisas em saúde capaz de contribuir efetivamente para o cumprimento das metas da ONU.

Geração de conhecimento, intervenções e ações de saúde

O artigo analisa a evolução do TDR como Programa Especial co-patrocinado por três agências das Nações Unidas, suas fases históricas e as mudanças -- por vezes radicais -- de sua estrutura organizacional/funcional. Este dinamismo moldou o TDR como um Programa em constante aperfeiçoamento, assegurando geração de conhecimento e sua transformação em ações de saúde pública no controle de doenças tropicais.

An improved silver staining procedure for schizodeme analysis in polyacrylamide gradient gels

A simple protocol is described for the silver staining of polyacrylamide gradient gels used for the separation of restriction fragments of kinetoplast DNA [schizodeme analysis of trypanosomatids (Morel et al., 1980)]. The method overcomes the problems of non-uniform staining and strong background color which are frequently encountered when conventional protocols for silver staining of linear gels. The method described has proven to be of general applicability for DNA, RNA and protein separations in gradient gels

Parasite genome projects and the Trypanosoma cruzi genome initiative

Since the start of the human genome project, a great number of genome projects on other "model" organism have been initiated, some of them already completed. Several initiatives have been started on parasite genomes, mainly through support from WHO/TDR, involving North-South and South-South collaborations, and great hopes are vested in that these initiatives will lead to new tools for disease control and prevention, as well as to the establishment of genomic research technology in developing countries. The Trypanosoma cruzi genome project, using the clone CL-Brener as starting point, has made considerable progress through the concerted action of more than 20 laboratories, most of them in the South. A brief overview of the current state of the project is given.

Inhibition of growth of Leishmania mexicana mexicana by Leishmania mexicana amazonensis during "in vitro" co-cultivation

Inhibiçäo do crescimento de um subespécie de Leishmania por exometabólitos de outra subespécie, um fenômeno ainda näo notificado, é sugerido em nossas recentes observaçöes em experimentos de clonagem celular com Leishmania mexicana mexicana e Leishmania mexicana amazonensis. Os clones foram identificados usando a técnica de análise de esquizodemas. O fenômeno observado é claramente relevante em estudos de isolamento parasitário, metabolismo, imunidade cruzada e quimioterapia

Paleoparasitology: perspectives with new techniques

Paleoparasitologia e o estudo de parasitos encontrados em material arqueologico. O desenvolvimento deste campo da pesquisa teve inicio com a identificacao de ovos de helmintos em tecidos mumificados, analise de coprolitos e, recentemente, atraves da biologia molecular. Neste artigo faz-se uma breve revisao da historia da paleoparasitologia com referencia especial aos estudos de ADN antigo (ancient DNA) em material arqueologico