Generation of neutralizing antibodies against Omicron, Gamma and Delta SARS-CoV-2 variants following CoronaVac vaccination

ABSTRACT Vaccination is a fundamental tool to prevent SARS-CoV-2 infection and to limit the COVID-19 pandemic. The emergence of SARS-CoV-2 variants with multiple mutations has raised serious concerns about the ability of neutralizing antibody responses elicited by prior vaccination to effectively combat these variants. The neutralizing capacity against the Gamma, Delta and Omicron variants of sera from individuals immunized with the CoronaVac vaccine remains incompletely determined. The present study evaluated 41 health care workers at the Faculdade de Medicina of the Universidade de Sao Paulo, in Sao Paulo, Brazil, naive to previous SARS- CoV-2 infection, who were vaccinated with two doses of the CoronaVac SARS-CoV-2 vaccine 28 days apart. Neutralizing antibody levels against the Gamma, Delta, and Omicron variants were measured at 32 and 186 days after the second vaccination. We also measured neutralizing antibodies against Omicron in 34 of these individuals following a subsequent booster immunization with the Pfizer vaccine. Quantification of neutralizing antibodies was performed using the Cytopathic Effect-based Virus Neutralization test. Neutralization antibody activity against the Gamma, Delta and Omicron variants was observed in 78.0%, 65.9% and 58.5% of serum samples, respectively, obtained at a mean of 32 days after the second immunization. This decreased to 17.1%, 24.4% and 2.4% of sera having activity against Delta, Gamma and Omicron, respectively, at 186 days post-vaccination. The median neutralizing antibody titers at 32 days were 1:40, 1:20 and 1:20 against Gamma, Delta and Omicron, respectively, and decreased to an undetectable median level against all variants at the later time. A booster immunization with the Pfizer vaccine elicited neutralizing antibodies against Omicron in 85% of subjects tested 60 days after vaccination. We conclude that two doses of the CoronaVac vaccine results in limited protection of short duration against the Gamma, Delta and Omicron SARS-CoV-2 variants. A booster dose with the Pfizer vaccine induced antibody neutralizing activity against Omicron in most patients which was measurable 60 days after the booster.

Absence of neutralizing antibodies against the Omicron SARS-CoV-2 variant in convalescent sera from individuals infected with the ancestral SARS-CoV-2 virus or its Gamma variant

Abstract Objectives: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. Methods: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. Results: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. Conclusions: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant. HIGHLIGHTS Individuals previously infected with SARS-CoV-2 ancestral strain do not develop neutralizing antibodies against the Omicron variant. Omicron variant escapes immune response after SARS CoV-2 previous infection with the SARS CoV-2 Gamma variant. Individuals previously infected with SARS-CoV-2 ancestral strain or with SARS-CoV-2 Gamma variant will likely have little protection if subsequently exposed to the Omicron variant.

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.

BK virus salivary shedding and viremia in renal transplant recipients

Abstract Objectives: This study aimed to verify the presence of polyomavirus BK (BKPyV) in the saliva of kidney transplant recipients and to correlate it with blood viremia. Material and Methods: We have conducted a cross-sectional study with a sample involving 126 renal transplant recipients. 126 samples of saliva and 52 samples of blood were collected from these patients. Detection and quantification of BKPyV were performed using a real-time PCR. To compare the presence of BKPyV in blood and saliva, the binomial proportion test was used. To verify associations between salivary shedding BKPyV and post-transplant periods (in months), the Mann-Whitney test was used. Spearman's correlation was used to correlate the viral load in the saliva with blood of kidney transplant recipients. Results: The mean age of the study group was 51.11±12.45 years old, and 69 participants (54.8%) were female, with a mean post-transplantation time of 4.80±6.04 months. BKPyV was quantified in several samples of saliva and blood, with medians of 1,108 cp/mL and 1,255 cp/mL, respectively. Only 16/52 (30.8%) participants presented BKPyV in blood, and 59/126 (46.8%) excreted the virus in saliva (p=0.004). BKPyV shedding was found in patients at a shorter post-transplantation period (3.86±5.25, p=0.100). A weak correlation was observed between viral quantification in saliva and blood (Spearman's correlation coefficient=0.193). Conclusion: The results of this study suggested that, although saliva excretes more BKPyV than blood, there is no reliable correlation between salivary shedding and blood viremia, showing two independent compartments of viral replication.

Role of T. cruzi exposure in the pattern of T cell cytokines among chronically infected HIV and Chagas disease patients

OBJECTIVES: The impact of Chagas disease (CD) in HIV-infected patients is relevant throughout the world. In fact, the characterization of the adaptive immune response in the context of co-infection is important for predicting the need for interventions in areas in which HIV and Chagas disease co-exist. METHODS: We described and compared the frequency of cytokine-producing T cells stimulated with soluble antigen of Trypanosoma cruzi (T. cruzi) using a cytometric assay for the following groups: individuals with chronic Chagas disease (CHR, n=10), those with Chagas disease and HIV infection (CO, n=11), those with only HIV (HIV, n=14) and healthy individuals (C, n=15). RESULTS: We found 1) a constitutively lower frequency of IL-2+ and IFN-γ+ T cells in the CHR group compared with the HIV, CO and healthy groups; 2) a suppressive activity of soluble T. cruzi antigen, which down-regulated IL-2+CD4+ and IFN-γ+CD4+ phenotypes, notably in the healthy group; 3) a down-regulation of inflammatory cytokines on CD8+ T cells in the indeterminate form of Chagas disease; and 4) a significant increase in IL-10+CD8+ cells distinguishing the indeterminate form from the cardiac/digestive form of Chagas disease, even in the presence of HIV infection. CONCLUSIONS: Taken together, our data suggest the presence of an immunoregulatory response in chronic Chagas disease, which seems to be driven by T. cruzi antigens. Our findings provide new insights into immunotherapeutic strategies for people living with HIV/AIDS and Chagas disease.

Apoyo virtual en el diagnóstico de lesiones cariosas según ICDAS en estudiantes de odontología / Virtual support in the carious lesions diagnosis according to ICDAS in dental students

Objetivo. Evaluar la influencia de la metodología expositiva con apoyo virtual en el diagnóstico de lesiones cariosas según ICDAS en alumnos del curso de carielogía. Materiales y métodos. Estudio descriptivo, correlacional, prospectivo, longitudinal realizado en 88 alumnos de la Facultad de Odontología de la Universidad de San Martín de Porres. Se intervino con dos tipos de metodología didáctica: la exposición a través de una clase magistral presentando imágenes de lesiones cariosas en piezas dentarias que se diagnosticaron con el sistema ICDAS y el apoyo virtual utilizando el programa E-Learning ICDAS. Ambas intervenciones tuvieron la misma temática e impartidas en sesiones diferentes. Después de cada intervención, se evaluó el nivel de conocimiento a través de un examen de 10 preguntas cuyos valores fueron: bueno (9-10), regular (6-8), malo (3-5), muy malo (0-2). El desempeño procedimental se evaluó diagnosticando visualmente ocho piezas dentarias con lesiones cariosas seleccionadas por un docente calibrado en el sistema ICDAS, registrando solo el código de caries del 0 al 6, considerando los valores: bueno (6,1-8), regular (4,1-6), malo (2,1-4), muy malo (0-2). Resultados. Existió diferencia estadísticamente significativa entre ambas metodologías utilizadas (p< 0,05). Comparando las calificaciones de las intervenciones expositivas y el apoyo virtual los valores promedio fueron 4,61 y 6,72 en el nivel de conocimiento; y en el desempeño procedimental 3,07 y 5,00 respectivamente. Conclusiones. El apoyo virtual influyó significativamente al incrementar el número de alumnos con calificaciones conceptuales y procedimentales más altas, demostrando la relevancia del apoyo de esta herramienta educativa en la enseñanza.

Objective. To evaluate the influence of the expositive methodology with virtual support in the diagnosis of carious lesions according to ICDAS in the students of dental caries course. Materials and methods. Descriptive, cross, prospective, longitudinal study conducted on 88 students of the faculty of dentistry of the San Martin de Porres university. Two types of teaching methods intervened: exposure,through a master class presenting images of carious lesions on teeth that were diagnosed with ICDAS system and the virtual support system using the E-Learning program ICDAS. Both interventions had the same subject and were imparted in different sessions. After each intervention, the knowledge level through a test of 10 questions was assessed, whose values were: good (9-10), regular (6-8), bad (3-5), very bad (0-2). The procedural performance was evaluated visually diagnosing eight teeth with carious lesions selected by acalibrated teacher in ICDAS system, recording only decay code from 0 to 6, considering the values: good (6.1-8), regular (4 1-6), bad (2.1-4), very bad (0-2). Results. There was statistically significant difference between the two methodologies (p <0. 05). Comparing the scores of expositive interventions and virtual support the average values were 4.61 and 6.72 in the knowledge level; performance and procedural performance were 3.07 and 5.00 respectively. Conclusions. The virtual support significantly influenced increasing the number of students with higher scores on the conceptual and procedural aspects, demonstrating the relevancy of the support of this educational tool in teaching.

Conocimientos y actitudes sobre bioseguridad en estudiantes de odontología de una universidad peruana / Knowledge and attitudes on biosecurity in dental students of a peruvian university

Evaluar el efecto de una capacitación educativa sobre bioseguridad en estudiantes de Odontología. Materiales y métodos. Estudio de tipo cuasiexperimental, longitudinal y prospectivo. La muestra estuvo conformada por 102 alumnos de Carielogía matriculados en el IV ciclo de la Facultad de Odontología de la Universidad de San Martín de Porres, durante el segundo semestre académico del 2013. Se evaluó los conocimientos y actitudes sobre bioseguridad de los participantes. Seguidamente, los alumnos fueron divididos en un grupo de estudio de 48 alumnos que recibirían una charla educativa sobre los principios de bioseguridad y un grupo control de 54 alumnos que no recibiría la mencionada capacitación. Finalmente, se procedió a evaluarlos nuevamente, comparando los resultados de ambos grupos. Resultados. No se encontró diferencia significativa en el conocimiento del grupo de estudio al ser comparado antes y después de la capacitación (p=0,100). Respecto a las actitudes, la capacitación dio como resultado una mejora tanto en el grupo de estudio como en el control (p=0,000 en ambos casos); al compararse ambos grupos se observó que esta mejora fue mayor en el grupo de estudio (p=0,016). No se encontró relación entre los conocimientos y las actitudes de los estudiantes, tanto antes como después de la capacitación (p =0,734 y p =0,873 respectivamente). Conclusiones. La capacitación sobre bioseguridad no influyó significativamente en el nivel de conocimiento de los alumnos, manteniéndose en un nivel ôregularõ. Respecto a las actitudes, ambos grupos pasaron de ôregularõ a ôbuenoõ, esta mejora fue mayor en el grupo de estudio. No se encontró correlación entre los conocimientos y las actitudes de los estudiantes...

Objective. To evaluate the effect of an educational training on biosecurity in dental students. Materials and methods. The study was quasi-experimental, longitudinal and prospective. The sample consisted of 102 students enrolled on the course of caries in the fourth cycle of the Faculty of Dentistry at the San Martin de Porres University, during the second semester of 2013. The initial assessment of knowledge and attitudes on biosafety of all participants was made .Then the students were divided into a study group of 48 students who receive training on the principles of biosecurity and another control group of 54 students who did not receivethe above mentioned training. Finally we proceeded to evaluate again the knowledge and attitudes about biosecurity, comparing the results of both groups. Results. No significant difference was found in the knowledge of the study group when compared before andafter training (p=0.10). Regarding attitudes, training resulted in an improvement in both the study group and the control (p=0.00 in both cases); comparing both groups, it was observed that the improvement was greater in the study group (p=0.02). No relationship between knowledge and attitudes of students, before and after training was found (p=0.73 and p=0.87 respectively). Conclusions. The educational intervention on biosecurity did not influence significantly the level of knowledge of the students, being kept in a ôregularõ level. Regarding attitudes, both groups passed from a ôregularõ to a ôgoodõ level, being this improvement greater in the study group. No relationship between knowledge and attitudes of students was found. KIRU. 2014;11(1):39-45...

Identification of respiratory virus in infants with congenital heart disease by comparison of different methods / Identificação de vírus respiratórios em crianças com cardiopatia congênita por comparação de diferentes métodos

Respiratory virus infections are the main cause of infant hospitalization and are potentially severe in children with congenital heart disease (CHD). Rapid and sensitive diagnosis is very important to early introduction of antiviral treatment and implementation of precautions to control transmission, reducing the risk of nosocomial infections. In the present study we compare different techniques in the diagnosis of respiratory viruses in CHD infants. Thirty-nine samples of nasopharyngeal aspirate were obtained from CHD infants with symptoms of respiratory infection. The Multiplex PCR (Seeplex® RV 12 ACE Detection) driven to the detection of 12 respiratory viruses was compared with the direct immunofluorescence assay (DFA) and PCR, both targeting seven respiratory viruses. The positivity found by DFA, Multiplex and PCR was 33.3 percent, 51.3 percent and 48.7 percent, respectively. Kappa index comparing DFA and Multiplex, DFA and PCR and PCR and Multiplex PCR was 0.542, 0.483 and 0.539, respectively. The concordance between techniques was considered moderate. Both Multiplex PCR (p = 0.001) and PCR (p = 0.002) detected significantly more respiratory virus than DFA. As the performance of the tests may vary, the combination of two or more techniques may increase diagnostic sensitivity favoring the diagnosis of co-infections, early introduction of antiviral therapy and implementation of appropriate measures.

Infecções respiratórias virais são a principal causa de hospitalização infantil e podem ser extremamente graves em crianças com cardiopatia congênita. O diagnóstico rápido e sensível é importante para a introdução precoce de tratamento antiviral e implantação de precauções para controle da transmissão, reduzindo o risco de infecções nosocomiais. Neste estudo, comparamos o desempenho de diferentes técnicas no diagnóstico de vírus respiratórios em crianças com cardiopatia congênita e sintomas respiratórios. Trinta e nove amostras de aspirado de nasofaringe foram obtidas de crianças com sintomas de infecção respiratória. Ensaio de PCR Multiplex que detecta 12 vírus respiratórios (Seeplex® RV 12 ACE Detection) foi comparado à Imunofluorescência Direta (IFD) e à PCR específica, ambas direcionadas a sete vírus. A positividade da IFD foi 33,3 por cento, do Multiplex foi 51,3 por cento e da PCR 48,7 por cento. O índice kappa comparando IFD e Multiplex, IFD e PCR, e PCR e Multiplex foi, respectivamente, 0,542, 0,483 e 0,539, sendo a concordância considerada moderada. O Multiplex e a PCR detectaram significantemente mais vírus que a IFD (p < 0,0001 e 0,002, respectivamente). Como o desempenho dos testes varia o uso de mais de uma técnica pode aumentar a sensibilidade diagnóstica favorecendo a introdução precoce de terapia antiviral e implantação de medidas profiláticas.

Pfaffia paniculata extract improves hydratation of eritrocytes in vitro and sickle cell disease symptoms

Purpose: Pfaffia paniculata, a plant known as Brazilian ginseng, has been claimed by some patients suffering from sickle cell disease to have beneficial effects. In order to examine this assertion, a powder extract was obtained from the roots of the plant. Pacients and methods. The extract was studied to verified the desickling properties in vitro. We studied the behavior of blood cells treated with Pfaffia paniculate extract in vitro through morpholofic analyses of blood cells incubated with paffia paniculate extract in vitro. Thirty Brazilian patients with sickle cell disease receiving capsules containing the powder extract of Pfaffia paniculata (500 mg each) every 8 hours or capsules containing placebo were followed up for three months. The number of erythrocytes, reticulocytes, sickle cells, and peripheral erythroblast, hemoglobin (HB), hematocrit (HT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), were determined in peripheral blood immediately before and 2 and 3 months after the beginning of the treatment. Results: Administration of Brazilian ginseng powder extract to patients having sickle cell resulted in decrease in sickle cells, erythroblast and reticulocytes in blood as well as increase in hemoglobin and hematocrit levels. Conclusion: The Pfaffic extract exhibited desickling properties when incubated with blood cells from deasese sickle cell disease patients or blood cells treated with 2% sodium methabisulphite. The clinical findings showed that treatment also led to improvement of the sintoms and signs in these patients.

Síndrome de Burnout en cirujanos dentistas / Burnout syndrome in dentist

Objetivo: El síndrome de Burnout es una enfermedad silenciosa que se desconocía hasta hace pocos años. Debido a los estudios de Maslach se dio a conocer esta enfermedad en profesionales que atienden a terceras personas y sus consecuencias. Material y método: Se realizó la investigación en 60 Cirujanos Dentistas, 30 del Hospital Central FAP y 30 del Centro Médico Naval. Se utilizó la ficha técnica del INVENTARIO BURNOUT DE MASLACH, la cual fue adaptada por N. Seisdedos, Departamento de I-D de TEA Ediciones, S. A. Madrid. Resultados: Existen profesionales con Síndrome de Burnout y otros en riesgo. El riesgo de los cirujanos dentistas en ambos centros hospitalarios fue similar y el 25% presentaron baja realización en el trabajo. Conclusiones: El Síndrome de Burnout era una enfermedad desconocida, pero actualmente las investigaciones revelan que se encuentra en aumento en diferentes profesionales, los cuales brindan servicios a terceras personas. En la presente investigación se encontró que el riesgo de padecer dicha enfermedad en los cirujanos dentistas fue similar en ambos centros hospitalarios. Existen profesionales en riesgo y otros que presentan el Síndrome de Burnout.

Objective: Burmout syndrome is a silent disease that was not known until a few years ago, due to Maslachs studies this disease was announced in professionals who attend to third persons and its consequences. Material and method: The research was made in 60 Surgeons Dentists, 30 of the Central Hospital FAP and 30 of the Medical Naval Center. It was used the technical sheet of the MASLACHS BURNOUT INVENTORY, which was adapted for N. Seisdedos, Department of Go of TORCH Editions, S. A. Madrid. Results: There are professionals with Burnout Syndrome and others on risk. The risk of the surgeons dentists in both hospital Centers were similar and 25 % presented low accomplishment in their work. Conclusions: The Syndrome of burnout was an unknown disease; but nowadays the researches reveal that it is in increase in different professionals, which offer services to third persons. In the present researche or was found that the risk of suffering the above mentioned disease in the Surgeons Dentists was similar in both Hospital Centers. There are Professionals on risk and others who present Burnout Syndrome.

Camperdown hemoglobin associated with beta° thalassemia in a Brazilian child

We report the coexistence of Hb Camperdown [beta104 (G6) Arg -> Ser] and beta°-thalassemia [beta39 (Gln -> stop codon)] in a nine-month-old Brazilian boy. He had a relatively more severe hypochromic and microcytic anemia in comparison to his mother's beta-thalassemia trait. His Hb Camperdown heterozygous father was clinically and hematologically normal. To our knowledge, this is the first description of an association of beta°-thalassemia with Hb Camperdown.

Standardization of procedures of Plasmodium falciparum antigen preparation for serologic tests

O objetivo deste estudo foi padronizar variaveis tecnicas para o armazenamento de Plasmodium falciparum e de seus componentes antigenicos. Sedimentos de parasitas foram obtidos do cultivo in vitro de P. falciparum e estocados em diferentes temperaturas por diferentes periodos de tempo. De cada variavel, foram extraidos os componentes antigenicos com detergente anfotero Zwittergent na presenca e na ausencia de inibidores de protease e submetidos ou nao a posterior dialise. Os produtos foram estocados por 15, 30 e 60 dias em diferentes temperaturas e caracterizados por SDS-PAGE. A atividade antigenica de cada extrato foi determinada por ELISA e Western blotting usando soros positivos e negativos para anticorpos IgG anti-formas eritrocitarias de P. falciparum. Os extratos antigenicos de parasitas estocados ate 10 dias a -20 graus Celsius ou por 2 meses a -70 graus Celsius e tratados com inibidores de protease, sob as diferentes condicoes de armazenamento, apresentaram melhor definicao das bandas proteicas no SDS-PAGE e Western blot e melhores resultados no ELISA, permitindo diferenciacao segura dos soros positivos e negativos

Propuesta de un Formato para la Evaluación de la Calidad Técnica de la Historia Clínica / Proposal of a Format for the Evaluation of the Clinical History's Technical Quality

La historia clínica es un documento privado de valor legal, científico e investigativo. Actualmente con las reformas instauradas en el campo de la salud en nuestro país se convierte en el medio más importante para analizar la calidad técnica y humana del personal de salud, por lo que la veracidad de la información consignada va a dar validez a la evaluación que se haga de los servicios de salud. Un formulario ágil y sencillo para evaluar la calidad de la historia clínica se hace necesario para medir de manera objetiva la eficiencia y eficacia de la institución prestdora de servicios; es por ello que en el presente artículo presentamos un formato para la evaluación de la calidad técnica de la historia clínica, basándonos en los registros diligenciados en la Fundación Oftalmológica de Santander de la Clínica Carlos Ardila Lulle