Seroimmunotyping of African swine fever virus

The extreme genetic and immunobiological heterogeneity exhibited by the African swine fever virus (ASFV) has been a significant impediment in the development of an efficacious vaccine against this disease. Consequently, the lack of internationally accepted protocols for the laboratory evaluation of candidate vaccines has become a major concern within the scientific community. The formulation of such protocols necessitates the establishment of a consensus at the international level on methods for the determination of homologous and heterologous isolates/strains of ASFV. The present article provides a comprehensive description of biological techniques employed in the classification of ASFV by seroimmunotypes. These techniques involve a holistic evaluation of ASFV isolates/strains based on their antigenic properties as determined by the hemadsorption inhibiting test (HAdI) using type-specific sera and an immunological test (IT) conducted on pigs inoculated with attenuated strains. The article outlines the methods for setting up the HAdI test, an IT on pigs, and the processes involved in the acquisition of type-specific serums for the HAdI test. It is pertinent to note that the definitive classification of seroimmunotype can only be ascertained after conducting an IT on pigs. The findings from the HAdI test or the phylogenetic analysis of the EP402R gene should be considered preliminary in nature

Description of Zoonotic Pseudocowpoxvirus Infection of Cattle in Russia

Parapoxviruses are worldwide epitheliotropic viruses that affect ruminants. Viruses of this genus have a narrow host range; however, the pseudocowpox virus (PCPV) also infects humans. Unfortunately, these cases are not well documented, and the epidemiology and the properties of the causative agents are not properly described. Here, we report the first case of PCPV in northern Russia (the Irkutsk region). The infection occurred in non-immune herds where no new arrivals of animals had been reported. Moreover, clinical signs of infection (skin lesions) were observed in humans. Based on the nucleotide identity and phylogenetic analysis of the partial-length B2L gene, the Irkutsk 2019 isolate was classified as PCPV. Phylogenetic analysis based on the nucleotide sequence of the B2L gene fragment of PCPV revealed a close phylogenetic relationship between the Irkutsk 2019 isolate and the PCPV strains isolated in Europe and the USA. The high degree of conservatism of the B2L gene does not allow for finding a correlation between their geographical origin and the results of phylogenetic analysis

Genomic characterization of peste des petits ruminants vaccine seed “45G37/35-k”, Russia

International audienceProduction of peste des petits ruminants (PPR) vaccines in Russia is based on two attenuated virus strains (“45G37/35-k” and “ARRIAH”) of common origin. Here, the identity of the strain PPRV/45G37/35-k was investigated using a full genome, Illumina deep sequencing approach. Phylogenomic analysis showed that PPRV/45G37/35-k belongs to the same lineage as the widely used PPRV vaccine strain Nigeria/75/1 (lineage II). However, 248 nucleotide differences separate the genomes of these vaccine strains, indicating that the PPRV vaccine strains produced in Russia are new strains not yet recognised by the World Organization for Animal Health (WOAH). Detailed information on the safety and efficacy of these vaccines should be provided to the WOAH before further national and international distribution

Data_Sheet_1_A highly pathogenic avian influenza virus H5N1 clade 2.3.4.4 detected in Samara Oblast, Russian Federation.docx

Avian influenza (AI) is a global problem impacting birds and mammals, causing economic losses in commercial poultry farms and backyard settings. In 2022, over 8,500 AI cases were reported worldwide, with the H5 subtype being responsible for many outbreaks in wild and domestic birds. In the territory of the Russian Federation, outbreaks of AI have been massively reported since 2020, both among domestic bird species and wild bird species. Wild migratory birds often serve as natural reservoirs for AI viruses, and interactions between bird species can lead to the emergence of new, highly pathogenic variants through genetic recombination between strains. In order to combat the widespread outbreaks of the disease and potential risks of further spread in 2021, monitoring studies were conducted in the Samara Oblast, the southeastern region of European Russian Federation. These studies aimed to diagnose and characterize circulating AI virus variants among wild migratory birds during waterfowl hunting in areas of mass nesting. Among the 98 shot birds, a highly pathogenic A/H5N1 AI virus was detected in a Eurasian Teal from the Bolshechernigovsky district. It was classified into clade 2.3.4.4 based on the cleavage site structure of HA. Phylogenetic analysis showed a high relatedness of the identified strain in the Samara Oblast with field isolates from Russia, Nigeria, Bangladesh, and Benin. The article emphasizes the importance of monitoring AI virus spread in both wild and poultry, highlighting the need for timely information exchange to assess risks. Further comprehensive studies are necessary to understand virus dissemination pathways.</p

Additional file 1 of Genomic characterization of peste des petits ruminants vaccine seed “45G37/35-k”, Russia

Additional file 1. Position and frequency of the 248 nucleotide differences separating the PPR vaccine strains Nigeria/75/1 (Nig75/1) and 45G37/35-k (FRCVM). Nucleotide positions corresponding to mutations associated to the attenuation of Nigeria/75/1 are in bold [14]

Additional file 2 of Genomic characterization of peste des petits ruminants vaccine seed “45G37/35-k”, Russia

Additional file 2. Distribution of nucleotide and amino acid differences separating the PPR vaccine strains Nigeria/75/1 (Nig75/1) and 45G37/35-k (FRCVM)

Inoculation with ASFV-Katanga-350 Partially Protects Pigs from Death during Subsequent Infection with Heterologous Type ASFV-Stavropol 01/08

African swine fever virus (ASFV) is an extremely genetically and phenotypically heterogeneous pathogen. Previously, we have demonstrated that experimental inoculation of pigs with an attenuated strain, Katanga-350 (genotype I, seroimmunotype I) (ASFV-Katanga-350), can induce protective immunity in 80% of European domestic pigs against the homologous virulent European strain Lisbon-57. At least 50% of the surviving pigs received protection from subsequent intramuscular infection with a heterologous virulent strain, Stavropol 01/08 (genotype II, seroimmunotype VIII) (ASFV-Stavropol 01/08). In this study, we assessed clinical signs, the levels of viremia, viral DNA, anti-ASFV antibodies and post-mortem changes caused by subsequent intramuscular injection with ASFV-Katanga-350 and heterologous ASFV-Stavropol 01/08. Inoculation of pigs with the ASFV-Katanga-350 did not protect animals from the disease in the case of the subsequent challenged ASFV-Stavropol 01/08. However, 40% of pigs were protected from death. Moreover, the surviving animals showed no pathomorphological changes or the presence of an infectious virus in the organs after euthanasia at 35 days post challenging. The ability/inability of attenuated strains to form a certain level of protection against heterologous isolates needs a theoretical background and experimental confirmation

Inoculation with ASFV-Katanga-350 Partially Protects Pigs from Death during Subsequent Infection with Heterologous Type ASFV-Stavropol 01/08

African swine fever virus (ASFV) is an extremely genetically and phenotypically heterogeneous pathogen. Previously, we have demonstrated that experimental inoculation of pigs with an attenuated strain, Katanga-350 (genotype I, seroimmunotype I) (ASFV-Katanga-350), can induce protective immunity in 80% of European domestic pigs against the homologous virulent European strain Lisbon-57. At least 50% of the surviving pigs received protection from subsequent intramuscular infection with a heterologous virulent strain, Stavropol 01/08 (genotype II, seroimmunotype VIII) (ASFV-Stavropol 01/08). In this study, we assessed clinical signs, the levels of viremia, viral DNA, anti-ASFV antibodies and post-mortem changes caused by subsequent intramuscular injection with ASFV-Katanga-350 and heterologous ASFV-Stavropol 01/08. Inoculation of pigs with the ASFV-Katanga-350 did not protect animals from the disease in the case of the subsequent challenged ASFV-Stavropol 01/08. However, 40% of pigs were protected from death. Moreover, the surviving animals showed no pathomorphological changes or the presence of an infectious virus in the organs after euthanasia at 35 days post challenging. The ability/inability of attenuated strains to form a certain level of protection against heterologous isolates needs a theoretical background and experimental confirmation

Immunobiological Characteristics of the Attenuated African Swine Fever Virus Strain Katanga-350

The African swine fever virus (ASFV) is the cause of a recent pandemic that is threatening the global pig industry. The virus infects domestic and wild pigs and manifests with a variety of clinical symptoms, depending on the strain. No commercial vaccine is currently available to protect animals from this virus, but some attenuated and recombinant live vaccine candidates might be effective against the disease. This article describes the immunobiological characteristics of one such candidate&mdash;the laboratory-attenuated ASFV strain, Katanga-350&mdash;which belongs to genotype I. In this study, we assessed clinical signs and post-mortem changes, the levels of viremia and the presence of viral DNA caused by injection of ASF virus strains Katanga-350, Lisbon-57, and Stavropol 08/01. Intramuscular injection of this strain protected 80% of pigs from a virulent strain of the same genotype and seroimmunotype (Lisbon-57). At least 50% of the surviving pigs received protection from subsequent intramuscular infection with a heterologous (genotype II, seroimmunotype VIII) virulent strain (Stavropol 08/01). Virus-specific antibodies were detectable in serum and saliva samples between 8&ndash;78 days after the first inoculation of the Katanga-350 strain (the observational period). The results suggested that this strain could serve as a basis for the development of a recombinant vaccine against ASF viruses belonging to seroimmunotype I

An Assessment of Diagnostic Assays and Sample Types in the Detection of an Attenuated Genotype 5 African Swine Fever Virus in European Pigs over a 3-Month Period

African swine fever virus causes hemorrhagic disease in swine. Attenuated strains are reported in Africa, Europe, and Asia. Few studies on the diagnostic detection of attenuated ASF viruses are available. Two groups of pigs were inoculated with an attenuated ASFV. Group 2 was also vaccinated with an attenuated porcine reproductive and respiratory syndrome virus vaccine. Commercially available ELISA, as well as extraction and qPCR assays, were used to detect antibodies in serum and oral fluids (OF) and nucleic acid in buccal swabs, tonsillar scrapings, OF, and blood samples collected over 93 days, respectively. After 12 dpi, serum (88.9% to 90.9%) in Group 1 was significantly better for antibody detection than OF (0.7% to 68.4%). Group 1&prime;s overall qPCR detection was highest in blood (48.7%) and OF (44.2%), with the highest detection in blood (85.2%) from 8 to 21 days post inoculation (dpi) and in OF (83.3%) from 1 to 7 dpi. Group 2&prime;s results were not significantly different from Group 1, but detection rates were lower overall. Early detection of attenuated ASFV variants requires active surveillance in apparently healthy animals and is only reliable at the herd level. Likewise, antibody testing will be needed to prove freedom from disease