The present invention provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the following genes: multigene-family 360 genes 9L, 10L, 11L, 12L, 13L and 14L; and multigene-family 505 genes 1R, 2R, 3R and 4R.

The invention further provides an attenuated African Swine Fever (ASF) virus which Lacks a functional version of the DP148R gene. The present invention also provides a vaccine comprising such an attenuated virus and its use to prevent ASF. Further, the invention relates to intranasal administration of an attenuated ASF virus.

The present invention provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the following genes: multigene-family 360 genes 9L, 10L, 11L, 12L, 13L and 14L; and multigene-family 505 genes 1R, 2R, 3R and 4R. The invention further provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the DP148R gene. The present invention also provides a vaccine comprising such an attenuated virus and its use to prevent ASF. Further, the invention relates to intranasal administration of an attenuated ASF virus.

The present invention relates to an attenuated African Swine Fever (ASF) virus, wherein: ?genes MGF 360-12L, 360-13L, 360-14L, 505-2R, 505-3R are deleted or are interrupted or mutated such that the genes are not transcribed and/or translated, ? ORF of ASFV_G_ACD_00520 is deleted or is interrupted or mutated such that it is not transcribed and/or translated, and ? genes MGF 505-1 R et 505-4R are truncated, compared to the genome of the corresponding unattenuated virus. The present invention also refers to a vaccine comprising the attenuated ASF virus, and its use in preventing African Swine Fever in a subject. The present invention also relates to an in-vitro method for obtaining the attenuated ASF virus, which comprises at least one step of thermal-attenuation of a virulent ASFV virus strain selected among Georgia 2007/1, Pig/HLJ/2018, a strain of ASF virus of genotype II or a genetically close ASF virus strain, and amplification by inoculation of Specific-Pathogen-Free pigs and selecting said attenuated ASF virus. The present invention refers to an in vitro method for the differential detection of the attenuated ASF virus and of the corresponding non-attenuated ASF virus as well.

The present disclosure belongs to the technical field of biology, and in particular relates to an attenuated strain of African swine fever virus (ASFV) with IPTG-induced deletion of a D1133L gene and use thereof. In the present disclosure, it is firstly found that the D1133L protein of ASFV can inhibit production of IFN-? and downstream cytokines ISG-15 and ISG-56, and can be used as an immunosuppressant with a relatively strong immunosuppressive effect. In addition, the attenuated strain of ASFV with IPTG-induced deletion of the D1133L gene is constructed. Specifically, a screening expression cassette is inserted into a position before the non-structural protein gene D1133L of the ASFV using an Escherichia coli lac operator-repressor system, to obtain a recombinant virus. In the presence of the IPTG, the recombinant virus has similar characteristics to a wild-type virus; and in the absence of the IPTG, the expression of the D1133L protein is inhibited.

The present disclosure provides a method of isolating and preparing live African Swine Fever (ASF) viruses (ASFV) and an ASFV vaccine composed of ASF virus particles. ASF viral components, and/or immunosuppressive protein factors. The ASFV vaccine can be used to immunize pigs and wild boars, or can be used to immunize species other than pig or wild boar, such as fowl, bovine, goat, rabbit, donkey or horse, to generate polyclonal immunoglobulins with broad-spectrum specificity to the ASFV. The ASFV-specific immunoglobulins then can be extracted and purified. The ASFV-specific immunoglobulins can provide acute treatment of ASF-infected pigs or wild boars or preventative treatment for pigs or wild boars at risk of ASF, for example that may have been exposed to ASFV or ASFV-infected subjects.

The present invention relates to attenuated African Swine Fever viruses. The attenuated viruses protect pigs against subsequent challenge with virulent virus. The present invention also relates to the use of such attenuated viruses to treat and/or prevent African Swine Fever. The invention also relates to EP402R proteins of African Swine Fever virus comprising particular amino acid substitutions, as well as polynucleotides encoding such proteins and African Swine Fever viruses comprising such proteins.

A method for monitoring the viability of a megavirus in animal feed or an animal feed ingredient generally includes inoculating the animal feed or animal feed ingredient with a surrogate virus as a proxy for the megavirus, subjecting the animal feed or animal feed ingredient to a treatment that inactivates the megavirus and the surrogate virus, subjecting the animal feed or animal feed ingredient to storage or transportation conditions for at least 14 days, and determining the viability of the surrogate virus in the animal feed or animal feed ingredient, thereby monitoring the viability of the megavirus in the animal feed or animal feed ingredient. In one or more embodiments, the megavirus is African swine fever virus (ASFV) and the surrogate virus is an ASFV surrogate virus. In some of these embodiments, the ASFV surrogate virus is a Coccolithovirus such as, for example, Emiliania huxleyi virus.

The present invention provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the following genes: multigene-family 360 genes 9L, 10L, 11L, 12L, 13L and 14L; and multigene-family 505 genes 1R, 2R, 3R and 4R. The invention further provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the DP148R gene. The present invention also provides a vaccine comprising such an attenuated virus and its use to prevent ASF. Further, the invention relates to intranasal administration of an attenuated ASF virus.

A method for generating progeny of an African swine fever (ASF) virus includes providing an isolated or purified fetal porcine lung alveolar macrophage cell capable of replicating the ASF virus, wherein the cell is cultured for at least 5 passages; exposing the cell to the ASF virus; and allowing the ASF virus to replicate in the cell; thereby generating progeny of the ASF virus.