Assessment of immune responses to a Comirnaty® booster following CoronaVac® vaccination in healthcare workers.

Background: The immunological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and immunisation is variable.

Objectives: To describe the humoral immune response by correlating IgA and IgG antibodies with NAbs titration following CoronaVac® immunisation and an mRNA (Comirnaty®) booster among healthcare workers (HCWs) and to compare the cytokine and interleukin profiles between HCWs vaccinated with CoronaVac and coronavirus disease 2019 (COVID-19) infected patients.

Methods: Samples from 133 HCWs collected at 20 (T1) and 90 (T2) days after CoronaVac immunisation and 15 (T3) days after a booster dose with the Comirnaty vaccine were analysed for IgA and IgG EIA and neutralisation assay.

Development of monoclonal antibodies against oropouche virus and its applicability to immunohistochemical diagnosis.

Orthobunyavirus oropouche ense virus (OROV), the causative agent of Oropouche fever, is widely dispersed in Brazil and South America, causing sporadic outbreaks. Due to the similarity of initial clinical symptoms caused by OROV with other arboviruses found in overlapping geographical areas, differential diagnosis is challenging. As for most neglected tropical diseases, there is a shortage of reagents for diagnosing and studying OROV pathogenesis.

Development of a quantitative NS1 antigen enzyme-linked immunosorbent assay (ELISA) for Zika virus detection using a novel virus-specific mAb.

Viruses from the Flaviviridae family, such as Dengue virus (DENV), Yellow fever virus (YFV), and Zika virus (ZIKV) are notorious global public health problems. ZIKV emergence in Polynesia and the Americas from 2013 to 2016 raised concerns as new distinguishing features set it apart from previous outbreaks, including its association with neurological complications and heightened disease severity. Virus detection is impaired as cross-reactivity to other closely related orthoflaviviruses is common among commercially available diagnostic kits.

Viremia and Inflammatory Cytokines in Dengue: Interleukin-2 as a Biomarker of Infection, and Interferon-α and -γ as Markers of Primary versus Secondary Infection.

The pathogenesis of (DENV) infection is complex and involves viral replication that may trigger an inflammatory response leading to severe disease. Here, we investigated the correlation between viremia and cytokine levels in the serum of DENV-infected patients. Between 2013 and 2014, 138 patients with a diagnosis of acute-phase DENV infection and 22 patients with a non-dengue acute febrile illness (AFI) were enrolled.

Development of an anti-SARS-CoV-2 monoclonal antibody panel and its applicability as a reagent in high-throughput fluorescence reduction neutralization and immunohistochemistry assays.

Since its emergence in late 2019, coronavirus disease 2019 (COVID-19) has caused millions of deaths and socioeconomic losses. Although vaccination significantly reduced disease mortality, it has been shown that protection wanes over time, and that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) may escape vaccine-derived immunity. Therefore, serological studies are necessary to assess protection in the population and guide vaccine regimens.

Spatial and Temporal Distribution of and Oviposition on the Coast of Paraná, Brazil, a Recent Area of Dengue Virus Transmission.

and are considered the most important vectors of arboviruses in the world. is the primary vector of dengue, urban yellow fever, chikungunya and zika in Brazil, and is considered a potential vector. Distribution patterns and the influence of climatic variables on the oviposition of and were evaluated in Morretes, a tourist city in the coastal area of Paraná State, Brazil, which has recently been experiencing cases of dengue fever.

Mayaro Virus: The State-of-the-Art for Antiviral Drug Development.

Mayaro virus is an emerging arbovirus that causes nonspecific febrile illness or arthralgia syndromes similar to the Chikungunya virus, a virus closely related from the family. MAYV outbreaks occur more frequently in the northern and central-western states of Brazil; however, in recent years, virus circulation has been spreading to other regions. Due to the undifferentiated initial clinical symptoms between MAYV and other endemic pathogenic arboviruses with geographic overlapping, identification of patients infected by MAYV might be underreported.

Human Neutrophils Present Mild Activation by Zika Virus But Reduce the Infection of Susceptible Cells.

The emergence of the (ZIKV) has highlighted the need for a deeper understanding of virus-host interactions in order to pave the way for the development of antiviral therapies. The present work aimed to address the response of neutrophils during ZIKV infection. Neutrophils are important effector cells in innate immunity implicated in the host's response to neurotropic arboviruses.

Pirahy virus: Identification of a new and potential emerging arbovirus in South Brazil.

Genomic and epidemiological surveillance are paramount for the discovery of new viruses with the potential to cross species barriers. Here, we present a new member of the genus found in and mosquitoes, tentatively named Pirahy virus (PIRAV). PIRAV was isolated from mosquito pools collected in a rural area of Piraí do Sul, South Brazil.

Placental Morphologic Similarities Between ZIKV-Positive and HIV-Positive Pregnant Women.

Zika virus (ZIKV) caused global concern due to Brazil's unexpected epidemic, and it was associated with congenital microcephaly and other gestational intercurrences. The study aimed to analyze the placenta morphometric changes of ZIKV-infected pregnant women (ZIKV group; n = 23) compared to placentas of HIV-infected (HIV group; n = 24) and healthy pregnant women (N-control group; n = 22). It also analyzed the relationship between the morphometric results and pathological alterations on conventional microscopy, gestational trimester of infection, and presence of the congenital Zika syndrome (CZS).

Invasive aspergillosis complication in yellow fever vaccine induced viscerotropic disease.

Invasive aspergillosis (IA) usually occurs in immunocompromised hosts, but in the last decade IA has emerged in critically ill non-neutropenic patients, as those with severe Influenza and Chronic Obstructive Pulmonary Disease (COPD). We report an unusual fatal case of disseminated IA in a non-immunocompromised patient following yellow fever vaccine-associated viscerotropic disease.

Downregulation of IGF2 expression in third trimester placental tissues from Zika virus infected women in Brazil.

Objectives: Screening for genes differentially expressed in placental tissues, aiming to identify transcriptional signatures that may be involved in ZIKV congenital pathogenesis.

Methods: Transcriptome data from placental tissues of pregnant women naturally infected with Zika virus during the third trimester were compared to those from women who tested negative for Zika infection. The findings were validated using both a cell culture model and an immunohistochemistry/morphological analysis of naturally infected placental tissues.

The citrus flavonoid naringenin impairs the in vitro infection of human cells by Zika virus.

The Zika virus (ZIKV) is an arthropod-borne virus that belongs to the Flaviviridae family. The ZIKV infection is usually asymptomatic or is associated with mild clinical manifestations; however, increased numbers of cases of microcephaly and birth defects have been recently reported. To date, neither a vaccine nor an antiviral treatment has become available to control ZIKV replication.

Identification of a novel alphavirus related to the encephalitis complexes circulating in southern Brazil.

In early 2017, an outbreak caused by an unknown and supposedly viral agent in the Marilena region of southern Brazil was investigated. Since the etiological agent causing the outbreak was not identified from human samples, mosquitoes from this region were collected. Three out of 121 mosquito pools collected from the region tested positive for alphavirus in molecular tests.

The Polyphenol-Rich Extract from an Endemic Medicinal Plant from Reunion Island, Inhibits the Early Stages of Dengue and Zika Virus Infection.

The recent emergence and re-emergence of viral infections transmitted by vectors, such as the Zika virus (ZIKV) and Dengue virus (DENV), is a cause for international concern. These highly pathogenic arboviruses represent a serious health burden in tropical and subtropical areas of the world. Despite the high morbidity and mortality associated with these viral infections, antiviral therapies are missing.

Vector Competence for West Nile Virus and St. Louis Encephalitis Virus () of Three Tick Species of the Genus (Acari: Ixodidae).

Many species of ticks are commonly found infesting wild birds in South America, where birds are important hosts for several arboviruses, such as West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). In this study, WNV and SLEV transmission experiments were performed to evaluate the vector competence of three South American tick species: , , and .

Identification of insect-specific flaviviruses in areas of Brazil and Paraguay experiencing endemic arbovirus transmission and the description of a novel flavivirus infecting Sabethes belisarioi.

Viral infection was examined with pan-flavivirus and pan-alphavirus sets of primers in mosquitoes collected in four South American regions with confirmed pathogenic arbovirus circulation. Positive pools for flavivirus infection were sequenced and screened for specific arboviruses, which were not detected. However, NS5 gene sequencing showed that most sequences corresponded to the insect-specific Culex flavivirus.