Anticuerpos anti-SARS-CoV-2 en personal de salud de un hospital pediátrico / SARS-CoV-2 antibodies among health care workers from a children's hospital

Introducción. En Argentina, el personal de salud ha sido el primero en vacunarse contra COVID-19, pero todavía existen pocos datos sobre la producción de anticuerpos IgG anti-S. Objetivos. Evaluar IgG específica contra glicoproteína spike del SARS-CoV-2 (IgG anti-S) posvacunación en personal de un hospital pediátrico. Explorar la asociación entre presencia de dichos anticuerpos, edad y antecedente de infección previa. Población y métodos. Estudio transversal que incluyó 193 trabajadores vacunados con los dos componentes de la vacuna Sputnik V. Se pesquisó el título de IgG anti-S y se registraron edad, antecedente de infección previa por SARS-CoV-2 y fecha de la vacunación. Resultados. El 98,6 % de los sujetos generó IgG anti-S. El título fue mayor en quienes habían cursado infección previamente (p <0,001), pero no hubo relación con la edad de los sujetos. Conclusión. Aportamos datos de generación de anticuerpos IgG anti-S posvacunación en personal de salud de un hospital pediátrico y exploramos algunos predictores.

Introduction. In Argentina, health care workers have been the first ones to receive the COVID-19 vaccine, but there are still few data on the production of anti-S IgG antibodies. Objectives. To assess specific IgG against the SARS-CoV-2 spike protein (anti-S IgG) after the vaccination of health care workers from a children's hospital. To explore the association between the presence of these antibodies, age, and history of prior infection. Population and methods. Cross-sectional study in 193 workers who received both doses of the two component Sputnik V vaccine. The anti-S IgG antibody titer was measured and age, history of prior SARS-CoV-2 infection, and date of vaccination were recorded. Results. Anti-S IgG antibodies were produced in 98.6% of the subjects. The titer was higher in those with prior infection (p < 0.001), but no relationship was established with subjects' age. Conclusion. We provide data on post-vaccination production of IgG anti-S antibodies among health care workers from a children's hospital and explore some predictors.

Overview of SARS-COV-2 infection at the Butantan Penitentiary Progression Center / Panorama da infecção pelo SARS-COV-2 no Centro de Progressão Penitenciária do Butantan

ABSTRACT OBJECTIVE To estimate the prevalence of exposure to the SARS-CoV-2 virus among individuals living in restricted freedom. METHODS A seroprevalence survey was carried out with the population of the female penitentiary of the Centro de Progressão Penitenciária (CPP) in Butantan (municipality of São Paulo), between June 24 and August 20, 2020. During this period, according to the Secretariat of Penitentiary Administration (SAP), the positivity of rapid tests among inmates ranged from 65% to 78%. The evaluation method used in the study was the "One Step COVID-19" rapid test (chromatography), from the company Wondfo, also using the RT-PCR method in symptomatic participants to confirm the viral condition. The study population consisted of 879 female inmates and 170 employees of the institution. RESULTS The prevalence of total antibodies (IgG/IgM) against the SARS-CoV-2 virus in the total population of 1049 study participants was 6.1%; among the population of 879 inmates,a prevalence of 5.8% was observed, and among the institution's employees, 7.5%. CONCLUSIONS The prevalence of covid-19 at the Butantan CPP was low, which is due to the implementation of simple prevention measures at the institution, such as the use of masks (with appropriate changes), emphasis on hygiene, hand washing and social distancing, in addition to other strategies, such as suspending inmates' visits from relatives and friends and cutting back on elective medical appointments and outside work.

RESUMO OBJETIVO Estimar a prevalência da exposição ao vírus SARS-CoV-2 entre indivíduos vivendo em restrição de liberdade. MÉTODOS Foi realizado inquérito de soroprevalência com a população da penitenciária feminina do Centro de Progressão Penitenciária (CPP) do Butantan (município de São Paulo), entre 24 de junho e 20 de agosto de 2020. Nesse período, segundo a Secretaria de Administração Penitenciária (SAP), a positividade dos testes rápidos entre detentos variou de 65 a 78%. O método de avaliação utilizado no estudo foi o teste rápido "One Step COVID-19" (cromatografia), da empresa Wondfo, empregando-se também o método RT-PCR em participantes sintomáticos para confirmação do quadro viral. A população do estudo foi constituída por 879 reeducandas e 170 funcionários da instituição. RESULTADOS A prevalência de anticorpos totais (IgG/IgM) contra o vírus SARS-CoV-2 na população total de 1.049 participantes do estudo foi de 6,1%; entre a população de 879 reeducandas foi observada prevalência de 5,8% e entre os servidores da instituição, 7,5%. CONCLUSÃO Houve baixa prevalência de covid-19 no CPP do Butantan, o que se deve à implementação de medidas de prevenção simples na instituição, como o uso de máscaras (com trocas adequadas), ênfase na higiene, lavagem das mãos e distanciamento social, além de outras estratégias, como suspensão de visitas de familiares e amigos das reeducandas, cortes de consultas médicas eletivas e do trabalho externo.

Infección por COVID 19: estudio seroepidemiológico de cohorte de base poblacional, estratificado por edad, en Asunción y Central / COVID 19 infection: age-stratified population-based cohort seroepidemiological study in Asunción and Central

INTRODUCCIÓN: La COVID-19, causada por el virus del síndrome respiratorio agudo severo tipo-2 (SARS-CoV-2), fue declarada pandémica en marzo de 2020. Los estudios de seroprevalencia son útiles para efectuar diversas estimaciones: la proporción de la población previamente infectada, cuantificar la magnitud de la transmisión, la tasa de letalidad, evaluar el efecto de intervenciones, y el grado de inmunidad de una población. OBJETIVOS: Determinar la extensión de la infección y la incidencia acumulada de infección mediante el estudio de seropositividad en pobladores de las regiones sanitarias de Asunción y Departamento Central de Paraguay. METODOLOGÍA: Estudio de cohorte poblacional. Se encuestaron 126 hogares en Asunción y 609 en el Departamento Central entre diciembre 2020 y marzo 2021. Se realizaron tres visitas a los hogares seleccionados. RESULTADOS: La tasa de testeo fue 66,6%, 1.699 personas (324 en Asunción y 1.375 en Central) de las 2.553 personas censadas. En la primera, segunda y tercera rondas, las seroprevalencias fueron en Asunción 15,5%, 15,4% y 14,3%, respectivamente; en Central 23,1%, 27,8% y 26,9%, respectivamente. Hubo una seroconversión entre la primera y segunda ronda de 5,9% y en la tercera ronda 6,5%. La seroprevalencia global acumulada fue de 26,9% (IC95%: 24,8-19,1); en Asunción 23,1% (IC95%: 18,9-28,0) y en Central 27,8% (IC95%: 25,5-30,2). El 8,5% de los participantes reportó síntomas; de estos, el 54,2% presentó serología positiva. CONCLUSIÓN: La sero-prevalencia fue alta con una baja proporción de encuestados sintomáticos.

BACKGROUND: COVID-19, caused by the severe acute respiratory syndrome virus type-2 (SARS-CoV-2), was declared a pandemic in March 2020. Seroprevalence studies are useful to estimate the proportion of the population previously infected, quantify the magnitude of transmission, estimate the fatality rate, evaluate the effect of interventions, and estimate the degree of immunity of the population. AIM: To determine the extension of the infection and the cumulative incidence of age-specific infection, determined by seropositivity in the population of the sanitary regions of Asunción and the Central Department of Paraguay. METHODS: Population-based cohort study. In Asunción 126 households and in the Central Department 609 were surveyed between December 2020 to March 2021. Three visits were made to the selected households. RESULTS: The testing rate was 66.6%, 1,699 people (324 in Asunción and 1,375 in Central) of the 2,553 people registered. In the first, second and third rounds, seroprevalences were 15.5%, 15.4% and 14.3% in Asunción, respectively; in Central 23.1%, 27.8% and 26.9%, respectively. There was a seroconversion between the first and second rounds of 5.9%, and in the third round 6.5%; the accumulated global seroprevalence was 26.9% (95% CI: 24.8-19.1); in Asunción 23.1% (95% CI: 18.9-28.0) and in Central 27.8% (95% CI: 25.5-30.2). 8.5% of the participants reported symptoms; of them, 54.2% had positive serology. CONCLUSION: The sero-prevalence was high with a low proportion of people with symptoms.

First record of antibodies to the bluetongue virus in ewe (Ovis aries) in the state of Amazonas, Brazil / Primeiro registro de anticorpos para o vírus da língua azul em ovino (Ovis aries) no estado do Amazonas, Brasil

The objective of this work was to describe the first record of antibodies to the Bluetongue Virus (BTV) in ewe, in the state of Amazonas. The ewe, which was in twin pregnancy, gave birth on May 9, 2015, but a lamb died hours after delivery. Veterinary service was then requested by the owner, where emaciation, loss of wool, pyrexia, apathy, dyspnea, mucoid nasal secretion, facial, lingual and submandibular edema were observed. There was a visit by the Agricultural Defense Agency of the State of Amazonas to the property and blood samples were collected from the animal. The whole blood and serum were sent to the National Agricultural Laboratory, where it was possible to detect the presence of specific antibodies to BTV, through the Agar Gel Double Immunodiffusion. The ewe was submitted to a new blood collection, following the same protocols and the samples were sent to the Biological Institute of São Paulo, confirmed diagnosis. The animal in a serious clinical condition, could not resist and died in July 2015. The occurrence of an allochthonous case, in an area where vector insects occur, can trigger an endemic process in the Amazon region. With this, the epidemiological control of these occurrences is necessary, in order to avoid the spread of the disease in the country.

O objetivo do trabalho foi descrever o primeiro registro de anticorpos para o Vírus da Língua Azul (VLA) em ovino, no estado do Amazonas. A ovelha, que se encontrava em gestação gemelar, pariu no dia 9 de maio de 2015, porém um cordeiro faleceu horas após o parto. Foi então solicitado serviço veterinário por parte do proprietário, onde foi observado emaciação, perda de lã, pirexia, apatia, dispneia, secreção nasal mucoide, edema facial, lingual e submandibular. Houve visita da Agência de Defesa Agropecuária do Estado do Amazonas na propriedade e coletadas amostras de sangue do animal. O sangue total e soro foram enviados ao Laboratório Nacional Agropecuário, no qual foi possível detectar a presença de anticorpos específicos para VLA, através do teste de Imunodifusão Dupla em Gel de Ágar. A ovelha foi submetida a uma nova coleta de sangue, seguindo os mesmos protocolos e as amostras foram enviadas ao Instituto Biológico de São Paulo, confirmando diagnóstico. O animal em estado clínico grave, não resistiu e veio a óbito em julho de 2015. A ocorrência de um caso alóctone, em uma área de ocorrência de insetos vetores, pode desencadear um processo de endemia na região amazônica. Com isso, o controle epidemiológico destas ocorrências, se fazem necessários, afim de se evitar a disseminação da doença no país.

Evaluación neuroepidemiológica a partir de anticuerpos antivirales de memoria generados por la vacuna triple viral / Neuro-Epidemiological Evaluation From Memory Antiviral Antibodies Generated By The MMR Vaccine

Introducción: La vacuna contra sarampión-parotiditis-rubéola es administrada en Cuba con un 99 por ciento de cobertura vacunal. Actualmente se plantea la baja inmunogenicidad de la cepa de parotiditis con que se fabrica por lo que resulta importante velar por la eficacia de las vacunas y su respuesta inmune protectora. Objetivos: Evaluar el comportamiento de los índices de anticuerpo antirubéola, antiparotiditis y antisarampión de acuerdo con la edad, y analizar la variación de la respuesta de anticuerpos antiparotiditis con respecto a estudios anteriores. Materiales y métodos: Se estudiaron muestras de suero y líquido cefalorraquídeo de 42 pacientes pediátricos con procesos neuroinflamatorios y se les cuantificó IgG total y albúmina y anticuerpos específicos contra los tres virus a partir de ensayos innmunoenzimáticos tipo ELISA. Se realizaron los reibergramas correspondientes e índices de anticuerpos específicos. Resultados: Se observó un incremento sostenido de anticuerpos contra los tres inmunógenos de forma general, sin diferencias significativas por razones de edad ni cambios notables posrevacunación. Existió un decrecimiento del índice de anticuerpos a medida que se alejaba de la fecha de revacunación por lo que se debe mantener una vigilancia en esos grupos de edades. La velocidad de producción de anticuerpos antiparotiditis fue mayor que frente a los otros virus, aunque no de forma significativa. Conclusiones: Esta vacuna garantiza protección por la uniformidad de la respuesta inmune de memoria inducida en todos los grupos de edades. Se demostró un aumento de protección de la población estudiada frente a la parotiditis con respecto a estudios previos(AU)

Introduction: The measles-mumps-rubella vaccine is administered in Cuba with 99 percent vaccination coverage. Currently, the low immunogenicity of the strain of mumps with which it is manufactured is raised, so it is important to ensure the effectiveness of vaccines and their protective immune response. Objectives: Evaluate the behavior of the anti-rubella, anti-mumps and anti-measles antibody indices according to age, and to analyze the variation of the anti-mumps antibody response with respect to previous studies. Materials and methods: Serum and cerebro-spinal fluid samples from 42 pediatric patients with neuro-inflammatory processes were studied and total IgG and albumin and specific antibodies against the three viruses were quantified from immunoenzymatic assays ELISA type. Corresponding reibergrams and specific antibody indices were performed. Results: A sustained increase in antibodies against the ethree immunogens was observed in general, without significant differences due to age or notable post-vaccination changes. There was a decrease in the antibody index as it moved away from the date of revaccination, so surveillance should be maintained in these age groups. The rate of production of anti-mumps antibodies was higher than against the other viruses, although not significantly. Conclusions: This vaccine guarantees protection by the uniformity of the memory induced immune response in all age groups. An increase in the protection of the studied population against mumps was demonstrated with respect to previous studies(AU)

Estudio de base poblacional de seroprevalencia y factores asociados a la infección por SARS-CoV-2 en Córdoba, Argentina / A population-based study on seroprevalence and factors associated with SARS-CoV-2 infection in Córdoba, Argentina / Estudo populacional de soroprevalência e fatores associados à infecção por SARS-CoV-2 em Córdoba, Argentina

Los estudios seroepidemiológicos permiten conocer la distribución indirecta de las enfermedades, detectando marcadores séricos de inmunidad y demostrando infecciones no diagnosticadas en la población general. El objetivo fue estimar la seroprevalencia de anticuerpos contra el SARS-CoV-2, en Córdoba, Argentina, entre diciembre de 2020 y enero de 2021, e identificar factores asociados a la contagiosidad del virus. Se realizó un estudio observacional transversal, de base poblacional, con 3.225 individuos mayores de 2 años, residentes en Córdoba Capital, que fueron seleccionados mediante un diseño de muestreo aleatorio en múltiples etapas, proporcional a la distribución por género, franja etaria y nivel socioeconómico de la población de Córdoba. Las características clínicas, antropometría y comorbilidades se recogieron mediante entrevistas. Se realizó un test serológico cualitativo para la detección de anticuerpos IgG antinucleocápside para SARS-CoV-2 (ARCHITECT, Abbott). La seroprevalencia del SARS-CoV-2 se estimó en la población y por franja de edad, sexo, nivel socioeconómico y presencia de las patologías estudiadas. Las razones de prevalencia (RP) se estimaron usando un modelo de regresión log-binomial. La seropositividad para SARS-CoV-2 fue de 16,68% (IC95%: 15,41-18,01). Tener entre 2 y 18 años, residir en barrios con nivel socioeconómico bajo y la presencia de obesidad, aumentaron la oportunidad de seropositividad (RP = 1,50; IC95%: 1,10-2,04, RP = 1,91; IC95%: 1,34-2,67 y RP = 1,39; IC95%: 1,04-1,85). Los resultados indican que en Córdoba Capital existen atributos diferenciales que aumentan la posibilidad de ser seropositivo para SARS-CoV-2. Esto permite dirigir estrategias de vigilancia epidemiológica para reducir la propagación del virus.

Seroepidemiological studies help identify the indirect distribution of diseases, detecting serological markers of immunity and demonstrating undiagnosed infections in the general population. The objectives were to estimate the seroprevalence of SARS-CoV-2 antibodies in Córdoba, Argentina, from December 2020 to January 2021 and to identify factors associated with the virus' contagiousness. A population-based cross-sectional observational study was performed in 3,225 individuals over two years of age living in Córdoba city, selected by multiple-stage random sampling proportional to distribution by gender, age group, and socioeconomic status in the city's population. Clinical characteristics, anthropometry, and comorbidities were collected by interview. Qualitative serological testing was performed for detection of SARS-CoV-2 nucleocapsid IgG antibodies (ARCHITECT, Abbott). SARS-CoV-2 seroprevalence was estimated for the total population and by age group, sex, socioeconomic status, and presence of target diseases. Prevalence ratios (PR) were estimated using a log-binomial regression model. SARS-CoV-2 seropositivity was 16.68% (95%CI: 15.41-18.01). Age 2 to 18 years, living in neighborhoods with low socioeconomic status, and obesity increased the odds of seropositivity (PR = 1.50; 95%CI: 1.10-2.04, PR = 1.91; 95%CI: 1.34-2.67 and PR = 1.39; 95%CI: 1.04-1.85). The results indicate that the city of Córdoba displays differential attributes that increase the likelihood of a positive SARS-CoV-2 antibody test. This allows targeting epidemiological surveillance strategies to reduce the spread of the virus.

Os estudos soroepidemiológicos permitem conhecer a distribuição indireta das doenças, detectando marcadores séricos de imunidade e demonstrando infecções não diagnosticadas na população geral. O objetivo foi estimar a soroprevalência de anticorpos contra o SARS-CoV-2, em Córdoba, Argentina, entre dezembro de 2020 e janeiro de 2021, e identificar fatores associados à contagiosidade do vírus. Um estudo observacional transversal foi realizado, de base populacional, com 3.225 indivíduos maiores de 2 anos, residentes em Córdoba Capital, que foram selecionados por meio de um delineamento de amostragem aleatória em múltiplos estágios, proporcional à distribuição de gênero, a faixa etária e o nível socioeconômico da população de Córdoba. As características clínicas, antropometria e comorbidades foram coletadas por meio de entrevistas. Um teste sorológico qualitativo foi realizado para a detecção de anticorpos IgG anti-nucleocapsídeo para SARS-CoV-2 (ARCHITECT, Abbott). A soroprevalência do SARS-CoV-2 foi estimada na população e por faixa etária, sexo, nível socioeconômico e presença das patologias estudadas. Razões de prevalência (RP) foram estimadas usando um modelo de regressão log-binomial. A soropositividade para SARS-CoV-2 foi de 16,68% (IC95%: 15,41-18,01). Ter entre 2 e 18 años, residir em bairros com nível socioeconômico baixo e a presença de obesidade aumentaram a chance de soropositividade (RP = 1,50; IC95%: 1,10-2,04, RP = 1,91; IC95%: 1,34-2,67 e RP = 1,39; IC95%: 1,04-1,85). Os resultados indicam que em Córdoba Capital existem atributos diferenciais que aumentam a possibilidade de ser soropositivo para SARS-CoV-2. Isso permite direcionar estratégias de vigilância epidemiológica para reduzir a propagação do vírus.

Prevalência de anticorpos contra SARS-CoV-2 em Mato Grosso, Brasil: pesquisa de base populacional / Prevalence of SARS-CoV-2 antibodies in the State of Mato Grosso, Brazil: a population-based survey / Prevalencia de anticuerpos contra el SARS-CoV-2 en Mato Grosso, Brasil: encuesta de base poblacional

Dados de soroprevalência oferecem informações relevantes relacionadas ao desenvolvimento e progressão de pandemia da COVID-19. Estimar a prevalência de anticorpos anti-SARS-CoV-2 em Mato Grosso, Brasil e sua distribuição segundo características sociodemográficas e econômicas. Inquérito soroepidemiológico de base populacional conduzido entre setembro e outubro de 2020, com indivíduos de 18 anos ou mais de idade, em dez municípios do Estado de Mato Grosso. As entrevistas e coleta de material biológico foram realizadas em domicílio, e a determinação de anticorpos IgG contra o SARS-CoV-2 foi feita por meio da quimioluminescência. Foram 4.306 indivíduos avaliados, e a prevalência de COVID-19 foi estimada em 12,5% (IC95%: 10,5; 14,7), variando de 7,4% a 24,3% entre os municípios. Não foram verificadas diferenças na prevalência da infecção segundo raça/cor da pele, escolaridade ou renda familiar, entretanto verificou-se menor prevalência entre indivíduos que residiam com algum morador que recebia aposentadoria, que não receberam auxílio financeiro emergencial e que a renda familiar não diminuiu após as medidas de distanciamento social para enfrentamento da epidemia. A prevalência de anticorpos contra SARS-CoV-2 estimada nesta pesquisa de base populacional é essencial para conhecer a magnitude da doença no estado e subsidiará ações de combate e controle da pandemia.

Seroprevalence data provide relevant information on the development and progression of the COVID-19 pandemic. The study aimed to estimate the prevalence of SARS-CoV-2 antibodies in Mato Grosso State, Brazil, and its distribution according to sociodemographic and economic characteristics. This population-based serological survey was conducted in September-October 2020 in individuals 18 years or older in ten municipalities (counties) in the state of Mato Grosso. Interviews and collection of biological samples were conducted in the households, and determination of IgG antibodies to SARS-CoV-2 was performed with chemiluminescence. A total of 4,306 individuals were evaluated, and COVID-19 prevalence was estimated at 12.5% (95%CI: 10.5; 14.7), ranging from 7.4% to 24.3% between municipalities. No significant differences were found in prevalence of infection according to race/color, schooling, or family income, but lower prevalence was seen in individuals with a pensioner living in the same household, who did not receive emergency financial aid, and whose family income had not decreased after social distancing measures during the epidemic. Estimated prevalence of SARS-CoV-2 antibodies in this population-based survey is essential to measure the magnitude of the disease and will back measures to confront and control the pandemic.

Los datos de seroprevalencia proporcionan información relevante relacionada con el desarrollo y la progresión de la pandemia del COVID-19. El objetivo fue estimar la prevalencia de anticuerpos anti-SARS-CoV-2 en Mato Grosso, Brasil, y su distribución según las características sociodemográficas y económicas. Encuesta seroepidemiológica de base poblacional, realizada entre septiembre y octubre de 2020 con individuos de los 18 años o más en diez municipios del estado de Mato Grosso. Las entrevistas y la recolección de material biológico se realizaron en el domicilio de los participantes, y para la determinación de anticuerpos IgG contra el SARS-CoV-2 se utilizó la quimioluminiscencia. Se evaluaron a 4.306 individuos, y la prevalencia del COVID-19 se estimó en un 12,5% (IC95%: 10,5; 14,7), que van del 7,4% al 24,3% entre los municipios. No se encontraron diferencias en la prevalencia de infección según la raza/color de la piel, la educación o los ingresos familiares; sin embargo, se encontró una menor prevalencia entre los individuos que vivían con un residente que recibía una pensión, que no recibía ayuda económica de emergencia y que los ingresos familiares no disminuyeron tras las medidas de distanciamiento social para hacer frente a la pandemia. La prevalencia de anticuerpos contra el SARS-CoV-2 estimada en esta investigación de base poblacional es imprescindible para conocer la magnitud de la enfermedad en el estado y subvencionar las acciones de enfrentamiento y control de la pandemia.

Respuesta inmunitaria al SARS-CoV-2 y factores asociados previo a la vacunación, en personal de salud de atención primaria en una comuna de Santiago, Chile / Immune response to SARS-CoV-2 in Primary Health Care personnel from a commune of Santiago, Chile

INTRODUCCIÓN: La pandemia de COVID-19 surgida en China a fines de 2019, se extendió rápidamente por el mundo, con casi 600 millones de casos y 6,3 millones de fallecidos en la actualidad. Los más afectados fueron los trabajadores de la salud con al menos tres veces más riesgo que la comunidad general de contraer la enfermedad. La mayoría de los estudios sobre seroprevalencia en trabajadores de la salud, se enfocan en establecimientos de atención hospitalaria y no se ha indagado con igual intensidad sobre lo que ocurre en la Atención Primaria de Salud (APS). OBJETIVOS: Determinar prevalencia de SARS-CoV-2 mediante anticuerpos IgG en personal de atención primaria de comuna de La Pintana y explorar sus características clínicas y factores de riesgo, previo a la vacunación en Chile. METODOLOGÍA: Diseño transversal realizado en noviembre 2020. Se recogieron datos sociodemográficos y clínicos mediante entrevista cara a cara, previa firma de consentimiento. Se determinó IgG específica mediante ELISA que utiliza proteína N y S. Las diferencias entre sujetos positivos y negativos se estudiaron mediante análisis bivariado y para asociaciones encontradas, se desarrollaron modelos multivariados controlando potenciales variables de confusión. El estudio contó con la aprobación del Comité Ético Científico de la Universidad del Desarrollo. RESULTADOS: Participaron 463 funcionarios (51,4%) encontrando prevalencia de 21,8%. Los factores de riesgo fueron edad menor, ser médico y haber sido contacto estrecho de un caso. El 22% fue asintomático. Entre quienes presentan anosmia o ageusia, la probabilidad de IgG+ fue superior a 70%. Los títulos de anticuerpos aumentan significativamente con la gravedad. CONCLUSIONES: La prevalencia en personal de atención primaria encontrada es concordante con la evidencia previa en trabajadores de salud. La menor edad y la profesión de médico se asocian a un mayor riesgo de enfermar.

BACKGROUND: The COVID-19 pandemic that emerged in Wuhan, China at the end of 2019, spread rapidly around the world with almost 600 million cases and 6.3 million deaths today. The most affected were health workers with at least three times the risk of contracting the disease than the general community. Most studies on seroprevalence in health workers focus on hospital care establishments and what happens in Primary Health Care (PHC) has not been investigated with the same intensity. AIM: To determine the prevalence of SARS-CoV-2 using IgG antibodies in primary health care personnel in La Pintana commune, risk factors and clinical characteristics, prior to vaccination in Chile. METHODS: A cross-sectional design carried out in November 2020. Sociodemographic and clinical data were collected through face-to-face interviews, after providing informed consent. Specific IgG was determined by ELISA using N and S proteins. The differences between positive and negative subjects were studied using bivariate analysis and multivariate models, controlling for potential confounding variables. The study was approved by the Universidad del Desarrollo Scientific Ethics Committee. RESULTS: 463 employees (51.4%) participated, finding a prevalence of 21.8%. The risk factors found were younger age, being a physician and having been in close contact with a case. 22% were asymptomatic. Among those with anosmia/ageusia, the probability of IgG+ was greater than 70%. Antibody titers increase with severity. CONCLUSIONS: Prevalence found in primary health care personnel is consistent with previous evidence. Younger age and medical profession are associated with a higher risk of illness.

COVID-T: una plataforma funcional para monitorear la respuesta de linfocitos t específicos de SARS-COV-2 en individuos vacunados y recuperados de COVID-19 / COVID-T: A functional platform to monitor SARS-CoV-2-specific T cell responses in vaccinated individuals and COVID-19 recovered patients

Resumen La rápida propagación del coronavirus SARS-CoV-2, agente causal de la enfermedad pandémica emergente COVID-19 y sus nuevas variantes, requiere del compromiso de la comunidad inmunológica para comprender la magnitud y naturaleza de la respuesta inmunológica adaptativa desarrollada por pacientes recuperados de COVID-19 e individuos vacunados con diferentes estrategias y protocolos, a los fines de imple mentar nuevas políticas sanitarias. En la actualidad, la determinación de la inmunidad contra SARS-CoV-2 se basa principalmente en la detección de anticuerpos específicos y la determinación de su actividad neutralizante. Sin embargo, a pesar de la alta sensibilidad de estos ensayos, un número considerable de pacientes e indivi duos vacunados carecen de respuesta humoral detectable, o evidencian una disminución rápida de la misma en el tiempo. Con el objetivo de estudiar la respuesta inmune celular desencadenada frente a SARS-CoV-2, en nuestro laboratorio desarrollamos la "Plataforma COVID-T" estrategia integral optimizada dirigida a caracte rizar y monitorear la respuesta de linfocitos T específicos de SARS-CoV-2 a partir de muestras de sangre de individuos vacunados y/o recuperados de COVID-19. Esta plataforma permite evaluar la naturaleza, magnitud y persistencia de la inmunidad celular T generada tanto por la infección con SARS-CoV-2, como por distintos esquemas y protocolos de vacunación en diferentes poblaciones de individuos. Asimismo, permite evaluar la respuesta inmunológica T generada frente a nuevas variantes del virus e identificar individuos sanos resistentes a SARS-CoV-2 con inmunidad pre-existente hacia coronavirus estacionales.

Abstract The rapid spread of the SARS-CoV-2, the caus ative agent of the emergent pandemic disease COVID-19, requires the urgent commitment of the immunology community to understand the adaptive immune response developed by COVID-19 convalescent patients and individuals vaccinated with different strategies and schemes, with the ultimate goal of implementing and optimizing health care and prevention policies. Currently, assessment of SARS-CoV-2-specific immunity is mainly focused on the measurement of the antibody titers and analysis of their neutralizing capacity. However, a considerable proportion of individuals lack humoral responses or show a progressive decline of SARS-CoV-2-specific neutral izing antibodies. In order to study the cellular response of convalescent patients and vaccinated individuals, we have developed the 'COVID-T Platform', an optimized strategy to study SARS-CoV-2-specific T cell responses. This platform allows assessment of the nature, magnitude and persistence of antigen-specific T-cell immunity in COVID-19-convalescent patients and vaccinated individuals. Moreover, it gives the opportunity to study cellular responses against emerging coronavirus variants and to identify individuals with cross-reactive immunity against seasonal coronaviruses.

Immunogenicity after CoronaVac vaccination

SUMMARY OBJECTIVE: This study aimed to investigate the seropositivity of CoronaVac-SinoVac vaccination in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) risk factors and comorbidities. METHODS: Immunoglobulin (IgG) antibody responses were examined on the 21st day after the second dose of CoronaVac-SinoVac 6 μg vaccine on the 28th day. SARS-CoV-2 IgG antibody levels were measured by using the enzyme-linked immunosorbent assay method in vaccinated health care workers (n=134) (Group I), vaccinated polymerase chain reaction (PCR) (+) who had coronavirus-19 (COVID-19) disease (n=21) (Group II), and unvaccinated PCR (+) (n=28) (Group III) participants. Subgroups were formed in Group I according to the presence of COVID-19 risk factors and comorbidities (diabetes mellitus, cardiovascular disease, and asthma/allergy) and demographic data. RESULTS: Seropositivity rates were 95.5, 100, and 89.3% for Groups I, II, and III, respectively. IgG antibody levels were found significantly higher in the group between the ages of 20-30 in group I compared to those aged 31-50 and over 50 (both p<0.01). It was found significantly higher in normal-weight individuals than in the overweight and obese group (both p<0.01). IgG antibody levels were found significantly lower in people with cardiovascular disease and diabetes mellitus compared with those who did not (p<0.05 and p<0.001, respectively). There was a negative correlation between IgG antibody response values and body mass index and age in Group I (r= −0.336, p<0.001 and r= −0.307, p<0.001, respectively). CONCLUSION: IgG antibody values decrease with age and with increasing body mass index. The presence of comorbidities (i.e., diabetes mellitus and cardiovascular disease) decreased COVID-19 IgG antibody values.

Hibridación de anticuerpos en la Covid-19 / Antibody hybridization in Covid-19

Introducción: El nuevo coronavirus tiene material genético. Esto permite a un receptor transformarse en el sitio de acción polibásica y es capaz de infectar a través de múltiples receptores de entrada y resaltar a las proteínas de tipo espiga (S). La proteína 'espiga' es una proteína de fusión viral de la Covid-19, es por ello que en la búsqueda terapéutica se establece las siguientes preguntas, ¿la hibridación de anticuerpos logrará ganar la guerra contra la pandemia de la Covid-19?; o ¿el plasma rico en anticuerpos puede mantener a las personas fuera de las unidades de cuidados intensivos? Estas preguntas radican en que los estudios actuales no establecen la verdadera utilidad de la terapia inmunológica. Objetivo: Presentar la utilidad de anticuerpos híbridos ante la actual pandemia de la Covid-19 y otros coronavirus. Métodos: Se desarrolló una revisión bibliográfica a partir de la evidencia existente acerca del panorama de la proteómica en el estudio del sistema inmune para combatir infecciones. Se utilizó un margen de tiempo entre el año 1999 al 2020. Se seleccionaron un total de 37 documentos que cumplen con los protocolos de inclusión en idioma inglés o español; en la búsqueda se utilizaron términos MeSH. Se escogieron estudios de orden observacional o analíticos; de carácter experimental, reporte de casos que dataran aspectos bioquímicos, biológicos, patológicos y clínicos del sistema inmune como blanco terapéutico ante la pandemia actual. El análisis documental fue realizado por el Grupo de Investigación en Salud de la Universidad del Cauca-Popayán, con apoyo y dirección de la Universidad de Houston, Texas (EEUU), con el apoyo de profesorado del Programa de Investigación Humana de la NASA. Resultados: La respuesta positiva para controlar esta pandemia está basada en los cuidados preventivos y en las posibles terapias innovadoras ante los nuevos coronavirus que logren transmitirse de animales a humanos. Se resalta el posible uso de anticuerpos de dominio único híbridos para frenar infecciones víricas nuevas. Conclusiones: Se resalta el posible uso de anticuerpos de dominio único híbridos para frenar infecciones víricas nuevas(AU)

Introduction: The new coronavirus has genetic material. This allows a receptor to transform into the polybasic site of action and it is capable of infecting through multiple entry receptors and highlighting spike-like (S) proteins. The spike protein is a viral fusion protein of Covid-19, which is why in the therapeutic search the following questions are established, will antibody hybridization succeed in winning the war against the Covid-19 pandemic? Or can antibody-rich plasma keep people out of intensive care units? These questions are that current studies do not establish the true utility of immune therapy. Objective: To settle the usefulness of hybrid antibodies to the current Covid-19 pandemic and other coronaviruses. Methods: A bibliographic review was developed from the existing evidence about the panorama of proteomics in the study of the immune system to fight infections. A time frame was used between 1999 and 2020. A total of 37 documents, in English or Spanish, that comply with the inclusion protocols were selected; MeSH terms were used in the search. Observational or analytical studies were chosen; experimental, case report dating biochemical, biological, pathological and clinical aspects of the immune system as a therapeutic target in the current pandemic. The documentary analysis was carried out by the Health Research Group of the Universidad del Cauca-Popayán, with the support and direction of the University of Houston, Texas (USA), with the support of faculty from NASA Human Research Program. Results: The positive response to control this pandemic is based on preventive care and possible innovative therapies for the new coronaviruses that manage to be transmitted from animals to humans. Conclusions: The possible use of hybrid single domain antibodies to stop new viral infections is highlighted(AU)

Severe acute respiratory syndrome Coronavirus 2. Seroepidemiology study in Argentinian slum / Estudio seroepidemiológico de enfermedad por Coronavirus 2019 en un barrio de Argentina

Abstract Most countries in Latin America have already reported thousands of confirmed cases and vulnerable populations are the most affected by the coronavirus disease 2019 (COVID-19) pandemic. Preventive measures such as hygiene, social distancing, and isolation, essential to stop the spread of coronavirus, are difficult to accomplish for vulnerable populations due to their living conditions. Seroepidemiological surveys are assets to measure the transmission for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Until July 1st, the incidence rate of SARS-CoV-2 infection in Barrio Padre Mugica, one of the largest slums in Buenos Aires City, was 5.9%. This study aimed to establish the prevalence of SARS-CoV-2 antibodies immunoglobulin G (IgG) immediately after the outbreak, and to identify neighbourhood, household and individual factors associated with seroconversion. The prevalence based on IgG was 53.4% (95% CI 52.8% to 54.1%). For each polymerase chain reaction (RT-qPCR) confirmed case, nine people tested IgG positive, indicating a high rate of undetected (probably asymptomatic) infections. Hence, the high rate of undiagnosed people suggests that clinical criteria and epidemiological nexus should be considered. The high seroprevalence observed in the context of an intense epidemic in a vulnerable area might serve as a reference to other countries. This study contributes to future decision making by understanding population immunity against SARS-CoV2 and its relation to living conditions and foccus that comprehensive biosocial, household-level interventions are needed.

Resumen Muchos países de América Latina han informado miles de casos confirmados y las poblaciones vulnerables son las más afectadas por la pandemia de la enfermedad por coronavirus 2019 (COVID-19). Las medidas preventivas como la higiene, el distanciamiento social y el aislamiento, fundamentales para frenar la propagación del coronavirus, son difíciles de lograr en estas poblaciones debido a sus condiciones de vida. Los estudios seroepidemiológicos son de gran utilidad para medir la transmisión del síndrome respiratorio agudo severo coronavirus 2 (SARS-CoV-2). Hasta el 1 de julio, la tasa de incidencia de la infección por SARS-CoV-2 en el Barrio Padre Mugica, uno de los barrios marginales más grandes de la ciudad de Buenos Aires, era del 5.9%. Este estudio tuvo como objetivo estimar la prevalencia de anticuerpos inmunoglobulina G (IgG) para SARS-CoV-2 inmediatamente después del brote, e identificar factores del barrio, hogar e individuales asociados con la seroconversión. La prevalencia basada en IgG fue del 53.4% (IC del 95%: 52.8% a 54.1%). Para cada caso confirmado por reacción en cadena de la polimerasa (RT-qPCR), nueve personas dieron positivo en IgG, lo que indica una alta tasa de infecciones no detectadas y probablemente asintomáticas. La alta tasa de personas no diagnosticadas sugiere que se deben considerar los criterios clínicos y el nexo epidemiológico. La alta seroprevalencia observada en el contexto de una intensa epidemia en una zona vulnerable podría servir de referencia a otros países. Este estudio contribuye a la toma de decisiones futuras al comprender la inmunidad de la población contra el SARS-CoV2 en su relación con las condiciones de vida y por su enfoque en la necesidad de intervenciones integrales a nivel del hogar.

Fatores associados à infecção pelo vírus da estomatite vesicular em equídeos no estado do Rio Grande do Norte, Brasil / Factors associated with infection by the vesicular stomatitis virus in equines in the state of Rio Grande do Norte, Brazil

Objetivou-se investigar a presença do Vírus da Estomatite Vesicular (VEV) e seus fatores de risco para ocorrência e disseminação da enfermidade em equídeos das mesorregiões Leste e Oeste Potiguar do estado do Rio Grande do Norte, Brasil. Foram analisadas pela técnica de virusneutralização, 809 amostras sanguíneas de equídeos provenientes de noventa propriedades de dezesseis municípios Potiguares durante os meses de julho de 2018 a fevereiro de 2019. Os fatores de riscos associados ao VEV foram avaliados por meio de questionário epidemiológico e os dados submetidos a análise estatística no programa IBM SPSS Statistics versão 21.0 com nível de confiança de 95%. Posteriormente, todas as variáveis estatisticamente significantes foram submetidas a análise de regressão de Poisson. A soroprevalência de anticorpos anti-VEV foi 24,6% (199/809), sendo 3,2% (13/402) de soropositivos na mesorregião Leste e 45,7% (186/407) na do Oeste Potiguar. Com relação aos sorotipos, observou-se uma prevalência de 3,8% (31/809) e 24,5% (198/809) para Indiana 2 e 3 respectivamente, com 15,1% (30/198) de coinfecção. Equídeos criados na mesorregião Oeste, em propriedades que não realizam quarentena e onde os animais enfermos são mantidos no rebanho, foram consideradas fatores predisponentes a infecção pelo VEV. Esses resultados demonstram a circulação do VEV em equídeos no Rio Grande do Norte, com destaque ao Oeste Potiguar, e sendo necessário a aplicação de medidas sanitárias que impeçam introdução e disseminação do vírus ente as espécies susceptíveis, principalmente em condições climáticas favoráveis para a sua manutenção, no ambiente de criação e pastagens.

This study aimed to investigate the presence of Vesicular stomatitis virus (VSV) and risk factors for its occurrence and dissemination in equines from the Eastern and Western mesoregions of the state of Rio Grande do Norte, Brazil. Blood samples were analyzed, by Serum Virus Neutralization Assay, from 809 animals belonging to 90 properties distributed in sixteen municipalities from July 2018 to February 2019. Risk factors were assessed using an epidemiological questionnaire. Data were submitted to statistical analysis using the software IBM SPSS Statistics, version 21.0 with a 95% confidence level. Also, all statistically significant variables were subjected to Poisson regression analysis. The occurrence of anti-VSV antibodies was 24.6% (199/809) with 3.2% (13/402) and 45.7% (186/407) of seropositivity in the Western and Eastern mesoregion, respectively. Regarding serotypes, there were an occurrence of 3.8% (31/809) and 24.5% (198/809) for Indiana 2 and 3, respectively, and 15.1% (30/198) of co-infection for both. Equines kept of the Western mesoregion, on properties that do not quarantine, and where sick animals are kept in the herd, were considered risk factors for LVV infection. These results demonstrate the presence of VSV in equines in Rio Grande do Norte, with emphasis on Oeste Potiguar, and that sanitary measures must be adopted to prevent the introduction and viral spreading among susceptible species, especially due to favorable climatic conditions for the maintenance of VSV in the breeding and pasture environment.

https://www.scielo.br/j/jbn/a/XCDXYHCGzjjG8sWsb8KGB3R/ / Infarto renal bilateral em paciente com infecção grave por COVID-19

Abstract Thromboembolic events are frequent in patients with COVID-19 infection, and no cases of bilateral renal infarctions have been reported. We present the case of a 41-year-old female patient with diabetes mellitus and obesity who attended the emergency department for low back pain, respiratory failure associated with COVID-19 pneumonia, diabetic ketoacidosis, and shock. The patient had acute kidney injury and required hemodialysis. Contrast abdominal tomography showed bilateral renal infarction and anticoagulation was started. Kidney infarction cases require high diagnostic suspicion and possibility of starting anticoagulation.

Resumo Fenômenos tromboembólicos são frequentes em pacientes com infecção por COVID-19 e nenhum caso de infarto renal bilateral havia sido relatado. Apresentamos o caso de uma paciente do sexo feminino, de 41 anos, com diabetes mellitus e obesidade, que deu entrada no serviço de urgência por lombalgia, insuficiência respiratória associada à pneumonia COVID-19, cetoacidose diabética e choque. A paciente apresentava lesão renal aguda e demandava hemodiálise. A tomografia abdominal contrastada mostrou infarto renal bilateral e foi iniciada anticoagulação. Os casos de infarto renal requerem alta suspeita diagnóstica e possibilidade de iniciar a anticoagulação.

Exanthematic dengue fever mimicking rubella

Abstract The authors present a case of dengue fever mimicking rubella. Male patient, in the second episode of dengue fever, presented afebrile, with diffuse morbilliform rash and craniocaudal progression, having subsequently affected his palms and soles. On the third day of clinical evolution, serologies did not indicate IgM, IgG, or NS1, but on the sixth day of evolution, IgM and IgG were reactive for dengue fever. Previous episodes of dengue are a risk factor for the development of more severe conditions, but this was atypical because the patient was afebrile and had a rubelliform rash. The case also illustrates an early IgG anamnestic response, as it was a reinfection.

Monitoreo seroepidemiológico de IGG contra el SARS-COV-2 en estaciones ferroviarias cabeceras de la Ciudad Autónoma de Buenos Aires / Seroepidemiological monitoring of SARS-CoV-2 IgG in main railway stations in the city of Buenos Aires, Argentina

INTRODUCCIÓN: Los estudios de seroprevalencia permiten monitorear la circulación del SARS-CoV-2 y dan información para evaluar medidas sanitarias. El objetivo fue conocer la proporción y evolución de la seropositividad en puntos de gran circulación de la Ciudad Autónoma de Buenos Aires (CABA) y las características clínico-epidemiológicas de los seropositivos, de abril a octubre de 2020. MÉTODOS: Se realizó un estudio descriptivo transversal de seis rondas de testeos rápidos serológicos y una encuesta de datos epidemiológicos. Se realizó un muestreo por conveniencia en tres estaciones ferroviarias cabeceras de CABA consideradas puntos de alto tránsito bidireccional del Área Metropolitana de Buenos Aires. RESULTADOS: Participaron 7339 personas. La proporción de seropositivos fue 0,6% (IC95%: 0,2-0,9) en la primera ronda y aumentó a 5,6% en la última (IC95%: 4,3-7). Al inicio aumentó la seropositividad en residentes de CABA y de la zona sur de la Región Metropolitana de Buenos Aires. El antecedente de haber presentado síntomas y el de contacto con personas con COVID-19 fueron las únicas variables relacionadas con el resultado de inmunoglobulina G positivo (p <0,05). El 56,1% (n = 97) de los seropositivos no tuvo síntomas. El 78,4% (n = 134) no fue diagnosticado en la etapa aguda. DISCUSIÓN: La seropositividad fue en ascenso en cada ronda, en coincidencia con la situación epidemiológica de la zona de residencia. Las características epidemiológicas como la proporción de seropositivos sin antecedentes de síntomas, reafirman la importancia de las medidas sanitarias poblacionales.

Population-level seropositivity trend for SARS-Cov-2 in Rio Grande do Sul, Brazil

ABSTRACT OBJECTIVE To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1-8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9-10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.

Living conditions, seroprevalence and symptoms of COVID-19 in slums in the Metropolitan Region of Vitória (Espírito Santo) / Condições de vida, soro prevalência e sintomas de COVID-19 em favelas na Região Metropolitana de Vitória (Espírito Santo)

ABSTRACT: Objectives: to estimate the prevalence of SARS-CoV-2 infection in residents of the Greater Vitória region living in subnormal and non-subnormal agglomerates, and to compare sociodemographic and clinical characteristics of total residents (infected and not infected with SARS-CoV-2) between them. Methods: Population-based prevalence study conducted by serological testing in 2020, with a study unit in households in Greater Vitória, grouped into census tracts classified as sub-normal agglomerates and non-sub-normal agglomerates. The two groups were compared in terms of prevalence and associated factors. The significance level adopted was 5%. Results: The prevalence found in the sub-normal clusters was 12.05% (95%CI 9.59-14.50), and in the non-sub-normal clusters 10.23% (95%CI 7.97-12.50) this difference was not statistically significant (p = 0.273). Comparing the sociodemographic characteristics, more people who declare themselves to be of mixed race were found in the sub-normal clusters, a higher percentage of illiterates and people with only elementary education, greater number of residents per household, longer stay in public transportation, sharing a bathroom with another household, fewer bedrooms per residence and higher frequency of irregular water supply when compared to non-sub-normal clusters (p < 0.05). Conclusions: The epidemiological characteristics of sub-normal clusters' residents show the social inequalities that can hinder control measures in a pandemic situation.

RESUMO: Objetivo: Estimar prevalência de infecção pelo SARS-CoV-2 em residentes na região da Grande Vitória, moradores de aglomerados subnormais e não subnormais, e comparar características sociodemográficas e clínicas dos residentes totais (infectados e não infectados com o SARS-CoV-2), entre esses aglomerados. Métodos: Estudo de prevalência de base populacional, por meio de teste sorológico realizado em 2020, com unidade de estudo em domicílios da Grande Vitória, agrupados em setores censitários classificados como aglomerados subnormais e aglomerados não subnormais. Os dois grupos foram comparados quanto à prevalência e aos fatores associados. O nível de significância adotado foi de 5%. Resultados: A prevalência encontrada em não aglomerados subnormais foi 12,05% (IC95% 9,59-14,50) e no grupo aglomerados não subnormais foi 10,23% (IC95% 7,97-12,50), e essa diferença não foi estatisticamente significante (p = 0,273). Comparando-se as características sociodemográficas, encontraram-se nos aglomerados subnormais mais pessoas que se autodeclaram da raça/cor parda, percentual maior de analfabetos e de pessoas apenas com ensino fundamental, maior número de moradores por domicílio, maior permanência em transporte coletivo, compartilhamento de banheiro com outro domicílio, menos dormitórios por residência e maior frequência de abastecimento irregular de água quando comparado aos aglomerados não subnormais (p<0,05). Conclusões: As características epidemiológicas dos moradores de aglomerados subnormais evidenciam as desigualdades sociais que podem dificultar as medidas de controle em uma situação de pandemia.

SARS-CoV-2 recombinant proteins stimulate distinct cellular and humoral immune response profiles in samples from COVID-19 convalescent patients

OBJECTIVES: In this preliminary study we investigated cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in blood samples from 14 recovered coronavirus disease 2019 (COVID-19) patients and compared them to those in samples from 12 uninfected/unvaccinated volunteers. METHODS: Cellular immunity was assessed by intracellular detection of IFN-γ in CD3+ T lymphocytes after stimulation with SARS-CoV-2 spike (S1), nucleocapsid (NC), or receptor-binding domain (RBD) recombinant proteins or overlapping peptide pools covering the sequence of SARS-CoV-2 spike, membrane and nucleocapsid regions. The humoral response was examined by ELISAs and/or chemiluminescence assays for the presence of serum IgG antibodies directed to SARS-CoV-2 proteins. RESULTS: We observed differences between humoral and cellular immune profiles in response to stimulation with the same proteins. Assays of IgG antibodies directed to SARS-CoV-2 NC, RBD and S1/S2 recombinant proteins were able to differentiate convalescent from uninfected/unvaccinated groups. Cellular immune responses to SARS-CoV-2 protein stimuli did not exhibit a specific response, as T cells from both individuals with no history of contact with SARS-CoV-2 and from recovered donors were able to produce IFN-γ. CONCLUSIONS: Determination of the cellular immune response to stimulation with a pool of SARS-CoV-2 peptides but not with SARS-CoV-2 proteins is able to distinguish convalescent individuals from unexposed individuals. Regarding the humoral immune response, the screening for serum IgG antibodies directed to SARS-CoV-2 proteins has been shown to be specific for the response of recovered individuals.

Self-prescribed Ivermectin use is associated with a lower rate of seroconversion in health care workers diagnosed with COVID, in a dose-dependent response

ABSTRACT Background: Over-the-counter use of ivermectin amongst other drugs as SARS-CoV-2 treatment has been increasingly common, despite the lack of evidence on its clinical efficacy. Objective: To evaluate the effect of ivermectin use on production of antibodies against SARS-CoV-2 in health care workers (HCW) diagnosed with COVID-19 and of Th1/Th2 cytokines by stimulated peripheral blood mononuclear cells of the same cohort (PBMCs). Methods: This cross-sectional study evaluated seroconversion and neutralizing antibodies production in HCW at Complexo Hospitalar Universitário Professor Edgard Santos (Salvador, Brazil), diagnosed with COVID-19 from May to July, 2020, as well as in vitro production of antibody against SARS-CoV-2 and Th1/Th2 cytokines. Analyses were performed between December 2020 and February 2021. Participants were stratified according to the use of ivermectin (≤ 1 dose vs. multiple doses) for treatment of COVID-19. Results: 45 HCW were included (62% women). Mean age was 39 years, and disease severity was similar across groups. Neutralizing antibodies were detected less frequently in multiple doses (70%) vs. ≤ 1 dose (97%) groups, p = 0.02). PBMCs of patients in multiple doses group also were less likely to produce antibodies against SARS-CoV-2 following in vitro stimulation with purified spike protein in comparison with patients in ≤ 1 dose group (p < 0.001). PBMC's production of Th1/Th2 cytokines levels was similar across groups. Abdominal pain (15% vs 46%, p = 0.04), diarrhea (21% vs. 55%, p = 0.05) and taste perversion (0% vs. 18%, p = 0.05) were more frequently reported by participants that used multiple doses of ivermectin. Conclusions: Although there was no evidence for differential disease severity upon ivermectin use for treatment of COVID-19 it was associated with more gastro-intestinal side-effects and impairment of anti-SARS-CoV2 antibodies production, in a dose dependent manner. This potentially impacts the effectiveness of immune response and the risk of reinfection and warrants additional studies for clarifying the mechanisms and consequences of such immunomodulatory effects.