Vacunas para SARS-CoV-2: diferentes estrategias de los desarrollos en curso / Vaccines for SARS-CoV-2: different strategies of ongoing developments

El objetivo de este artículo es proporcionar una guía que sirva para la interpretación y seguimiento de los esfuerzos que se están desarrollando en todo el mundo con el objetivo de obtener una vacuna que pueda generar inmunidad contra el nuevo coronavirus SARS-CoV-2 de 2019, el agente causante de la enfermedad por coronavirus denominada COVID-19. Cinco meses después de haber sido detectada la enfermedad, ya hay 102 vacunas en distintos estadios de desarrollo, registradas por la Organización Mundial de la Salud (OMS), correspondientes a 8 plataformas vacunales con diferentes estrategias, y todos los días aparecen nuevas. Esto representará un enorme desafío de organismos internacionales, para la evaluación, comparación y selección de aquellas que cumplan con los criterios regulatorios indispensables de seguridad y eficacia y que, por otro lado, puedan ser producidas en cantidades suficientes para abastecer la demanda mundial. (AU)

The objective of this article is to provide a guide to help the interpretation and monitoring the efforts that are being carried out worldwide to obtain a vaccine that will be able to generate immunity against the new 2019 SARS-CoV-2 coronavirus, the viral agent causes the disease named COVID-19. Five months after the disease was detected, there are already 102 vaccines at different stages of development, registered by World Health Organization (WHO), corresponding to 8 vaccination platforms base on different strategies, and every day new ones appear. This will represent a huge challenge for international organizations, to evaluate, compare and selects those that will meet the essential regulatory criteria of safety and efficacy and that, would be able to be produced in enough quantities to supply the worldwide demand. Key words: SARS-Cov-2 vaccine, vaccine platform, COVID-19 strategy, attenuated virus, viral vector, viral proteins, viral DNA, viral RNA, nucleic acids, viral like particles, WHO. (AU)

Detection of parvovirus B19 viral DNA in serum of women of childbearing age in Xiangyang City / 公共卫生与预防医学

Objective To analyze the infection of human parvovirus B19 among women of childbearing age in Xiangyang City, and to provide a reference for pregnant women's health care. Methods A total of 303 women of childbearing age in Xiangyang City from 2018 to 2019 were selected as the research subjects. B19 virus DNA in serum of the subjects was detected by nested PCR technology. The differences in the detection rate of B19 viral DNA among normal pregnancy, abnormal pregnancy, and infertility serum were statistically analyzed. The differences in the detection rate of B19 virus DNA among women of childbearing age at different ages were compared. Results The detection rate of B19 viral DNA in all 303 women of child-bearing age was 27.72%. The detection rate of B19 virus DNA in 26-35 year old women was higher than that in other age groups. The detection rate of B19 virus DNA in abnormal pregnancy group was significantly higher than that in normal pregnancy group (P <0.05). Conclusion The detection rate of B19 virus DNA in abnormal pregnancy and infertility group was significantly higher than that in normal pregnancy group, with the detection rate of B19 virus in 26-35 year old women of childbearing age being the highest among all age groups. It is necessary to strengthen the screening of B19 virus in pregnant women of childbearing age in this region to reduce its impact on fetal abortion.

Result Patterns and Characteristics of HBeAg and HBV DNA in Patients with Chronic Hepatitis B

BACKGROUND: Discrepancies in the results between hepatitis B e-antigen (HBeAg) and hepatitis B virus (HBV) DNA levels pose difficulties in the management of chronic hepatitis B (CHB). This study aims to better understand the different phases of CHB and to detect additional meaningful parameters for CHB patients. METHODS: We collected datasets of HBeAg and HBV DNA levels measured during 2016 and the follow-up results for CHB patients for past 3 years. We analyzed the collected data by applying the definitions of CHB clinical phase and compared the results of semi-quantitative and quantitative HBeAg assays. RESULTS: About 55% of 2,291 result pairs from CHB patients showed qualitative agreement between HBeAg and HBV DNA results. HBeAg (−) CHB was reported in 16.49%, while hepatitis B surface antigen (HBsAg) loss occurred in 0.18% among 1,146 patients annually. HBeAg reversion occurred in 2.74% of 839 patients that experienced HBeAg seroconversion. Patients with HBeAg (+) and HBV DNA (−) showed statistically significant differences in the levels and percentage abnormality of alanine aminotransferase (ALT) based on whether HBV DNA was ‘Target not detected’ or ‘Detected,

Prevalence of occult hepatitis b infection in iranian cancer patients before chemotherapy treatment / Prevalência de infecção oculta da hepatite B em pacientes iranianos com câncer antes do tratamento de quimioterapia

ABSTRACT Background Occult hepatitis B infection is characterized by negative hepatitis B surface antigen (HBsAg) and also detectable hepatitis B virus (HBV) -DNA, with or without hepatitis B core antibody (anti-HBc). HBV reactivation in individuals under immunosuppressive therapy is critical, occurring in occult HBV. Objective In this study, we aimed to determine the prevalence of occult HBV infection among hepatitis B surface antigen negative in cancer patients before receiving chemotherapy. Methods Sera from 204 cancer patients who were negative for HBsAg, were tested for anti-HBc antibodies. The samples that were negative for HBsAg but positive for anti-HBc also examined for HBV-DNA by polymerase chain reaction (PCR). Results Of the 204 HBsAg negative blood samples, 11 (5.4%) samples were positive for anti-HBc antibodies. HBV-DNA was detected in 9/11 (81%) of anti-HBc positive samples. Occult HBV infection in hematological cancers was more than solid cancers, 4.8% and 4.3% respectively. There was no significant difference in HBc antibody positivity based on vaccination, previous blood transfusions, history of familial hepatitis or biochemical parameters (ALT, AST, total and direct bilirubin levels) (P>0.05). Conclusion Screening of occult HBV infection by HBsAg, HBV DNA and anti HB core antibody should be suggested as a routine investigation in cancer patients before receiving chemotherapy.

RESUMO Contexto A infecção oculta da hepatite B caracteriza-se por antígeno de superfície da hepatite B (AgHBs) negativo com vírus detectável da hepatite B (HBV) -DNA, com ou sem anticorpo de núcleo da hepatite B (anti-HBc). A reativação do HBV em indivíduos sob terapia imunossupressora é crítica, originando a infecção oculta pelo VHB. Objetivo Este estudo teve como objetivo determinar a prevalência de infecção oculta pelo VHB entre em pacientes com câncer e com antígeno de superfície da hepatite B negativo antes de receber quimioterapia. Métodos Soro de 204 pacientes com câncer que foram negativos para AgHBs, foram testados para anticorpos anti-HBc. As amostras que foram negativos para AgHBs, mas positivo para anti-HBc foram também examinadas para HBV-DNA, por reação em cadeia da polimerase. Resultados Entre 204 amostras de sangue AgHBs negativas, 11 (5,4%) foram positivos para anticorpos anti-HBc. HBV-DNA foi detectado em 9/11 (81%) das amostras positivas de anti-HBc. Infecção oculta de VHB em câncer hematológico foi maior que em cânceres sólidos, 4,8% e 4,3% respectivamente. Não houve diferença significativa na positividade anti-HBc, com base na vacinação, transfusões de sangue anteriores, história de hepatite familiar ou parâmetros bioquímicos (ALT, AST, total e níveis de bilirrubina total) (P & gt; 0,05). Conclusão A triagem de infecção oculta por AgHBs, HBV-DNA e anti-anticorpo de núcleo HB deve ser sugerida como uma investigação de rotina em pacientes com câncer antes de receber a quimioterapia.

Restriction enzyme analysis of the human cytomegalovirus genome in specimens collected from immunodeficient patients in Belém, State of Pará, Brazil / Análise de restrição enzimática do genoma viral do citomegalovírus humano em espécimes clínicos de pacientes imunodeficientes, Belém, Estado do Pará

INTRODUCTION: Human cytomegalovirus is an opportunistic betaherpesvirus that causes persistent and serious infections in immunodeficient patients. Recurrent infections occur due to the presence of the virus in a latent state in some cell types. It is possible to examine the virus using molecular methods to aid in the immunological diagnosis and to generate a molecular viral profile in immunodeficient patients. The objective of this study was to characterize cytomegalovirus genotypes and to generate the epidemiological and molecular viral profile in immunodeficient patients. METHODS: A total of 105 samples were collected from immunodeficient patients from the City of Belém, including newborns, hemodialysis patients, transplant recipients and HIV+ patients. An IgG and IgM antibody study was completed using ELISA, and enzymatic analysis by restriction fragment length polymorphism (RFLP) was performed to characterize viral genotypes. RESULTS: It was observed that 100 percent of the patients had IgG antibodies, 87 percent of which were IgG+/IgM-, consistent with a prior infection profile, 13 percent were IgG+/IgM+, suggestive of recent infection. The newborn group had the highest frequency (27 percent) of the IgG+/IgM+ profile. By RFLP analysis, only one genotype was observed, gB2, which corresponded to the standard AD169 strain. CONCLUSIONS: The presence of IgM antibodies in new borns indicates that HCMV continues to be an important cause of congenital infection. The low observed genotypic diversity could be attributed to the small sample size because newborns were excluded from the RFLP analysis. This study will be continued including samples from newborns to extend the knowledge of the general and molecular epidemiology of HCMV in immunodeficient patients.

INTRODUÇÃO: O citomegalovírus é um betaherpesvírus oportunista, causador de infecções persistentes e graves em pacientes imunodeficientes. As infecções recorrentes ocorrem devido à presença do vírus em estado de latência, em alguns tipos celulares, o que possibilita a pesquisa viral por métodos moleculares para auxiliar nos diagnósticos imunológicos, assim como traçar o perfil epidemiológico e molecular viral em pacientes imunodeficientes. O objetivo deste estudo foi caracterizar os genótipos de citomegalovírus e traçar o perfil epidemiológico e molecular viral em pacientes imunodeficientes. MÉTODOS: Um total de 105 amostras foi coletado de pacientes imunodeficientes da Cidade de Belém, incluindo recém-nascidos, hemodialisados, transplantados e pacientes HIV+. Foi realizada a pesquisa de anticorpos IgG e IgM pelo método ELISA e análise enzimática pelo método restriction fragment length polymorphism (RFLP) para caracterização dos genótipos virais. RESULTADOS: Foi observado que 100 por cento dos pacientes apresentavam anticorpos IgG, 87 por cento eram IgG+/IgM-perfil de infecção pregressa; e 13 por cento IgG+/ IgM+ sugestivo de infecção recente. O grupo dos recém-nascidos apresentou maior frequência (27 por cento) do perfil IgG+/IgM+. Na análise por RFLP, foi observado um único genótipo, o gB2, que corresponde ao padrão genotípico da cepa AD169. CONCLUSÕES: A presença de anticorpos IgM nos recém-nascidos indica que o vírus CMV continua sendo causa importante de infecção congênita; a baixa diversidade genotípica pode ser atribuída ao tamanho amostral devido a exclusão dos recém-nascidos na análise por RFLP. Esse estudo será continuado incluindo amostras de recém-nascidos a fim de contribuir para um amplo conhecimento da epidemiologia geral e molecular do citomegalovírus em pacientes imunodeficientes da Cidade de Belém.

Papilomavírus humano e a detecção do DNA viral no carcinoma espinocelular da cavidade oral / Human papillomavirus and the detection of viral DNA in oral squamous cell carcinoma

A associação entre a infecção pelo papilomavírus humano (HPV) e o câncer de colo uterino e de outros sítios anogenitais já está estabelecida. A medicina molecular tem evidenciado mecanismos específicos relacionados à carcinogênese induzida pelo HPV e revelado a importante interação de oncoproteínas virais com genes de controle do ciclo celular. Estudos epidemiológicos e em medicina molecular também sugerem que a infecção pelo HPV pode estar associada ao câncer de cabeça e pescoço. Isso se deve à significativa frequência da infecção pelo HPV, principalmente os tipos de alto-risco nessa situação. Entretanto, são necessárias pesquisas básicas para descrever o estado físico do vírus em uma variedade de tipos celulares e a sua interação com outros genes celulares, assim como estudos epidemiológicos auxiliariam na compreensão da associação entre o HPV e fatores de risco para o desenvolvimento de neoplasias, características demográficas e modos de transmissão. Isso nos motivou a revisar a literatura considerando os aspectos biológicos da infecção pelo HPV e seu potencial papel etiológico no câncer de cabeça e pescoço; a detecção da infecção pelo HPV no tecido normal, em lesões benignas e pré-malignas da cavidade oral, bem como no carcinoma oral, discutindo também os métodos de detecção do HPV. Verificamos taxas de detecção muito divergentes, com frequência variando de 0 a 78%, justificadas por vários fatores: diferentes métodos e técnicas, diferentes amostras de tecido e variabilidade interlaboratorial. A análise da literatura nos levou a concluir que: (1) os estudos epidemiológicos não demonstram clara associação entre a infecção pelo HPV e o câncer oral; (2) os estudos experimentais comprovam a ação de genes virais causando a imortalização celular; (3) os métodos de detecção do DNA viral em tecido da cavidade oral devem ser aperfeiçoados objetivando menor interferência nos resultados.

Human papillomaviruses (HPV) are known for causing cancers of the cervix and other anogenital sites. The molecular medicine has emphasized specific mechanisms related to the carcinogenesis, induced by HPV and revealing the interaction of the HPV oncoproteins with important genes of the cell cycle control. Epidemiologic and molecular medicine studies have also suggested that infection by HPV may be associated to the head and neck cancer. The prevalence of HPV, especially high-risk types, suggests a potential etiologic role for the virus in head and neck cancer. Nevertheless, more basic research is needed to describe the physical state of the virus in a variety of cell types and the interaction with the other genes. In addition, epidemiologic research is required to further understand the association between HPV, demographic and other risk factors, as well as possible routes of transmission. We reviewed the literature considering biologic aspects of the HPV and its potential etiologic role in head and neck cancer; the prevalence of HPV infection in benign, precancerous and neoplastic lesions of the oral cavity; the prevalence of HPV infection in oral cancer and methods of HPV detection. We can verify very different detection rates, with frequency varying from 0% to 78%, justified by many reasons: different method and technique, different tissue sample and laboratory variety. By this means, we can conclude: (1) epidemiologic studies do not show association between infection by HPV and oral cancer; (2) testing studies confirm the action of viral genes immortalizing the cells; (3) the detection methods of viral DNA in oral cavity tissue have to be improved, aiming less interference in the results.

Effect of Multiple Freeze-thaw Cycles of Various Types of Specimens on the Quantitative and Qualitative analysis of Herpesvirus DNA

The recent development of molecular diagnostic assays like as polymerase chain reaction (PCR) has provided powerful tools for the diagnosis of viral infection in the clinical fields. To ensure optimal therapeutic and prognostic value, it is important to establish whether viral load measurements are affected by repeated freeze-thaw (FT) cycles since the freezing of clinical samples is a universal method of specimen storage. This study was done to determine the effect of freezing and thawing of various samples on the quantitation and positivity of viral DNA. For this study, three different types of samples being used frequently in clinical fields were selected. Those samples contained ovine herpesvirus-2 (OvHV-2), a member of the gamma herpesviruses (genus Rhadinovirus). Two OvHV-2 DNA positive plasma samples, two peripheral blood mononuclear cell (PBMC) samples, and two nasal swab samples were randomly selected. They were carefully aliquated into 8 tubes for each sample. The aliquoted samples were frozen and thawed 0, 3, 6, 9, 12, 15, 18, and 21 times for each aliquot and then analyzed for changes on DNA levels and positivity. OvHV-2 DNA positivity and quantitation were tested by using nested PCR and real-time PCR, respectively. Twenty-one cycles of freezing and thawing did not significantly change this herpesviral DNA positivity in any of the samples tested. However, the decreases of viral DNA copies were observed in all samples by the increasing of FT cycles. In conclusion, the integrity of herpesviral DNAs in clinical specimens may be degraded by the increasing FT cycles. These results implicate that there is a need to aliquot specimen when it is first collected in order to reduce FT cycles during its analysis.