Publications by authors named "Nico Halwe"
Article Synopsis
- * Researchers created "single-cycle infection SARS-CoV-2 viruses" (SCVs) that are safer and have modified immune properties, successfully tested in Syrian hamsters.
- * The new vaccine showed complete protection against SARS-CoV-2 in vaccinated animals, preventing virus transmission and causing no tissue damage, indicating its potential for a stronger immune response than natural infections.
In March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.
View Article and Find Full Text PDFIn March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.
View Article and Find Full Text PDFThe emergence of SARS-CoV-2 in late 2019 initiated a global pandemic, which led to a need for effective therapeutics and diagnostic tools, including virus-specific antibodies. Here, we investigate different antigen preparations to produce SARS-CoV-2-specific and virus-neutralizing antibodies in chickens (n = 3/antigen) and rabbits (n = 2/antigen), exploring, in particular, egg yolk for large-scale production of immunoglobulin Y (IgY). Reactivity profiles of IgY preparations from chicken sera and yolk and rabbit sera were tested in parallel.
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- - Approved vaccines are good for preventing severe COVID-19, but new variants and transmission need a stronger immune response, leading to the creation of modified live-attenuated vaccines (LAVs) that recode the SARS-CoV-2 genome.
- - The new vaccines, called OTS-206 and OTS-228, are designed to be safe and effective, with OTS-228 showing no side effects or transmission in animal studies, and can be given intranasally.
- - A single dose of OTS-228 not only provides strong immunity against the original SARS-CoV-2 strain but also offers broad protection against variants like Omicron, making this approach potentially valuable for other emerging viruses as well. *
Article Synopsis
- H9N2 influenza A viruses have become common in poultry in the Middle East and Asia, leading to an increase in human infections.
- A novel strain of H9N2 was found in Egyptian fruit bats, which shares genetic traits with current avian strains, indicating possible recent genetic mixing.
- Research shows that bat H9N2 can replicate and spread in ferrets, infect human lung tissue, and evade certain antiviral defenses, highlighting its potential risk as a pre-pandemic virus.
Knowledge about early immunity to SARS-CoV-2 variants of concern mainly comes from the analysis of human blood. Such data provide limited information about host responses at the site of infection and largely miss the initial events. To gain insights into compartmentalization and the early dynamics of host responses to different SARS-CoV-2 variants, we utilized human angiotensin converting enzyme 2 (hACE2) transgenic mice and tracked immune changes during the first days after infection by RNAseq, multiplex assays, and flow cytometry.
View Article and Find Full Text PDFThe SARS-CoV-2 Omicron subvariants BA.1 and BA.2 exhibit reduced lung cell infection relative to previously circulating SARS-CoV-2 variants, which may account for their reduced pathogenicity.
View Article and Find Full Text PDFSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Omicron and its subvariants (BA.2, BA.4, BA.
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- * Bivalent mRNA vaccines, which use a lower dose of both Beta and Delta spike proteins, generate similar immune responses and offer protection against SARS-CoV-2 in tested mouse models.
- * These bivalent vaccines also show effectiveness in reducing viral replication and generating neutralizing antibodies against emerging variants like Omicron, suggesting a promising strategy for future vaccination efforts.
Article Synopsis
- The Omicron-BA.1 variant of concern became the dominant strain globally in early 2022, prompting the need for extensive research using primary cell cultures and animal models to understand its characteristics compared to the Delta variant.* -
- In laboratory studies, Omicron-BA.1 showed increased early replication in human nasal cells but less replication in bronchial cells; however, in animal models like hamsters and ferrets, Delta variant remained more dominant.* -
- The research revealed that the spike gene from Omicron-BA.1 leads to lower replication and pathogenicity in certain mice, while also indicating that this variant may escape immune responses generated by mRNA vaccines, contributing to its dominance over other variants.*
Emerging variants of concern (VOCs) are driving the COVID-19 pandemic. Experimental assessments of replication and transmission of major VOCs and progenitors are needed to understand the mechanisms of replication and transmission of VOCs. Here we show that the spike protein (S) from Alpha (also known as B.
View Article and Find Full Text PDFThe ongoing SARS-CoV-2 pandemic necessitates the fast development of vaccines. Recently, viral mutants termed variants of concern (VOC) which may escape host immunity have emerged. The efficacy of spike encoding mRNA vaccines (CVnCoV and CV2CoV) against the ancestral strain and the VOC B.
View Article and Find Full Text PDFInfluenza A viruses (IAV) of subtype H9N2, endemic in world-wide poultry holdings, are reported to cause spill-over infections to pigs and humans and have also contributed substantially to recent reassortment-derived pre-pandemic zoonotic viruses of concern, such as the Asian H7N9 viruses. Recently, a H9N2 bat influenza A virus was found in Egyptian fruit bats (), raising the question of whether this bat species is a suitable host for IAV. Here, we studied the susceptibility, pathogenesis and transmission of avian and bat-related H9N2 viruses in this new host.
View Article and Find Full Text PDFAfter experimental inoculation, severe acute respiratory syndrome coronavirus 2 infection was confirmed in bank voles by seroconversion within 8 days and detection of viral RNA in nasal tissue for up to 21 days. However, transmission to contact animals was not detected. Thus, bank voles are unlikely to establish effective transmission cycles in nature.
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- * Research shows that the D614G variant binds more effectively to the ACE2 receptor and replicates better in human airway cells and animal models compared to other variants.
- * The study concludes that the D614G mutation gives the virus a competitive advantage in transmission, helping to explain its widespread prevalence globally.
Article Synopsis
- - The D614G substitution in the SARS-CoV-2 spike protein became the dominant variant during the COVID-19 pandemic, but its advantages in replication and transmission were unclear.
- - Research shows that the S-614G variant binds more effectively to human ACE2 and replicates better in human airway cultures and animal models.
- - The findings indicate that the S-614G variant offers a competitive edge, especially during transmission phases, explaining its spread and prevalence globally.