Seven infectious bronchitis virus genotypes including South American-origin G1-11 and Asian-origin GVI-1 circulated in southern African poultry from 2010 to 2020

Article

Author: Strydom, Christine ; Abolnik, Celia

Infectious bronchitis virus (IBV) affects the respiratory, urogenital and reproductive systems of chickens and causes major economic losses. Biosecurity and vaccinations are used to limit the disease's impact, and identifying the circulating strains is important for selecting appropriate vaccines. The partial spike (S1) genes of 364 IBVs, isolated from commercial chickens in Botswana, Eswatini, Namibia and South Africa from 2010 to 2020, were phylogenetically analyzed. Seven genotypes were identified: 184 viruses (50,5 %) were classified as genotype GI-19 (QX) and 78 (21,4 %) were GI-1 (Mass/H120). Thirty-nine (10,7 %) were genotype GI-13 (4/91), 29 (8,0 %) were GVI-1 (TC07-2), 19 (5,2 %) were GI-23 (Variant 2), and 13 (3,6 %) were GI-11 (UFMG/G-Brazil). Two (0.5 %) viruses belonged to the GIV-1 (DE/072/92) genotype. Genotype GI-11 had not been reported outside South America before but has evidently circulated in South Africa for at least a decade. Similarly, genotype GVI-1, previously thought to be restricted to Asia, has been present in southern Africa since at least 2010. Prior to 2013, only Mass and H120 vaccines were permitted to be used in South Africa, but since 2013 793/B (GI-13), QX (GI-19), 4-91 (GI-13) and Variant 2 (GI-23) live attenuated vaccines were permitted. Accordingly, the four IBV variants we identified were putative recombinants of genotypes G1-1 and G1-19, G1-13 and G1-19, or G1-13 and unknown IBV strains, but these variant viruses did not spread extensively or persist in the region. The phylogenetic evidence points to imported contaminated poultry and poultry products as the source of new IBV genotypes in southern Africa.

04 May 2023·Avian Pathology

The efficacy of an inactivated avian influenza H5N1 vaccine against an African strain of HPAI H5N8 (clade 2.3.4.4 B)

Article

Author: Love, Nicolette ; Maartens, Louis H. ; Dawson, Susan ; Erasmus, Baltus J. ; Frizzo da Silva, Leticia

Highly pathogenic avian influenza (HPAI) viruses from the Goose/Guangdong/96-lineage emerged in Southeast Asia and subsequently spread to the Middle East, Africa and Europe, infecting a range of birds and mammals (including humans). This lineage of H5 viruses can efficiently establish itself in wild birds after circulating among gallinaceous poultry, facilitating reassortment with low pathogenic avian influenza (LPAI) virus strains, enhancing dispersal over long distances and contributing to endemicity. The detection of HPAI H5N8 virus (clade 2.3.4.4B) in 2017 in the Mpumalanga Province of South Africa marked the beginning of an epidemic that devastated the South African poultry industry. Vaccines were tested to assess protection against the circulating field strain. This article describes the performance of a reverse genetics inactivated H5N1 vaccine from Zoetis (RG-H5N1), with 96.1% identity to the circulating HPAI H5N8 virus. Two locally formulated benchmarks, one containing an H5N8 antigen homologous to the field strain (Benchmark-H5N8), the other containing a heterologous (87.6% identity to field virus) LPAI H5N1 antigen (Benchmark-H5N1), were included for comparison. Efficacy was assessed in specific pathogen-free (SPF) chickens using a prime-boost approach (injections at days 21 and 45), followed by a challenge with a South African HPAI H5N8 isolate (70 days of age). The Zoetis RG-H5N1 vaccine and Benchmark-H5N8 outperformed the Benchmark-H5N1 in terms of humoral response against the H5N8 antigen and reduction of shedding. The Zoetis RG-H5N1 vaccine protected 100% of the chickens against clinical disease and death. This study confirmed that antigenically matched inactivated vaccines could induce robust protection and markedly reduce viral shedding.RESEARCH HIGHLIGHTSConditionally licensed vaccine protected against HPAI H5N8 (clade 2.3.4.4B).Complete protection against clinical disease and mortality.Drastic reduction of viral shedding after challenge.

01 Jun 2021·Virus ResearchQ3 · MEDICINE

African horse sickness virus NS4 protein is an important virulence factor and interferes with JAK-STAT signaling during viral infection

Q3 · MEDICINE

Article

Author: Wall, Gayle V ; Wright, Isabella M ; van Staden, Vida ; Erasmus, Baltus J ; Potgieter, A Christiaan ; Barnardo, Carin

African horse sickness virus (AHSV) non-structural protein NS4 is a nucleocytoplasmic protein that is expressed in the heart, lung, and spleen of infected horses, binds dsDNA, and colocalizes with promyelocytic leukemia nuclear bodies (PML-NBs). The aim of this study was to investigate the role of AHSV NS4 in viral replication, virulence and the host immune response. Using a reverse genetics-derived virulent strain of AHSV-5 and NS4 deletion mutants, we showed that knockdown of NS4 expression has no impact in cell culture, but results in virus attenuation in infected horses. RNA sequencing (RNA-seq) was used to investigate the transcriptional response in these horses, to see how the lack of NS4 mediates the transition of the virus from virulent to attenuated. The presence of NS4 was shown to result in a 24 hour (h) delay in the transcriptional activation of several immune system processes compared to when the protein was absent. Included in these processes were the RIG-I-like, Toll-like receptor, and JAK-STAT signaling pathways, which are key pathways involved in innate immunity and the antiviral response. Thus, it was shown that AHSV NS4 suppresses the host innate immune transcriptional response in the early stages of the infection cycle. We investigated whether AHSV NS4 affects the innate immune response by impacting the JAK-STAT signaling pathway specifically. Using confocal laser scanning microscopy (CLSM) we showed that AHSV NS4 disrupts JAK-STAT signaling by interfering with the phosphorylation and/or translocation of STAT1 and pSTAT1 into the nucleus. Overall, these results showed that AHSV NS4 is a key virulence factor in horses and allows AHSV to overcome host antiviral responses in order to promote viral replication and spread.

100 Deals associated with Deltamune (Pty) Ltd.

100 Translational Medicine associated with Deltamune (Pty) Ltd.

Corporation Tree

Boost your research with our corporation tree data.

view full example data

Pipeline

Pipeline Snapshot as of 20 Jul 2025

No data posted

Deal

Boost your decision using our deal data.

view full example data

Translational Medicine

Boost your research with our translational medicine data.

view full example data

Profit

Explore the financial positions of over 360K organizations with Synapse.

view full example data

Grant & Funding(NIH)

Access more than 2 million grant and funding information to elevate your research journey.

view full example data

Investment

Gain insights on the latest company investments from start-ups to established corporations.

view full example data

Financing

Unearth financing trends to validate and advance investment opportunities.

view full example data

AI Agents Built for Biopharma Breakthroughs

Accelerate discovery. Empower decisions. Transform outcomes.

Get started for free today!

Accelerate Strategic R&D decision making with Synapse, PatSnap’s AI-powered Connected Innovation Intelligence Platform Built for Life Sciences Professionals.

Start your data trial now!

Synapse data is also accessible to external entities via APIs or data packages. Empower better decisions with the latest in pharmaceutical intelligence.

Bio

Bio Sequences Search & Analysis

Chemical

Chemical Structures Search & Analysis

Deltamune (Pty) Ltd.

Overview

Related

Corporation Tree

Pipeline

Pipeline Snapshot as of 20 Jul 2025

Deal

Translational Medicine

Profit

Grant & Funding(NIH)

Investment

Financing