The present invention relates to the use of an immunogenic composition that comprises a porcine circovirus type 3 (PCV3) antigen for treatment of several clinical manifestations (diseases). Preferably, the clinical manifestations are associated with a PCV3 infection.

Engineered SARS-CoV-2 variants having a combination of attenuating modifications, and their use as live-attenuated SARS-CoV-2 vaccines, are described. The recombinant genome of the live-attenuated SARS-CoV-2 encodes a modified spike (S) protein with a deletion of the polybasic site (PRRA); encodes a modified non-structural protein 1 (Nsp1) with K164A and H165A substitutions; and includes a mutation that prevents expression of open reading frames (ORFs) 6, 7a, 7b and 8. The disclosed live-attenuated SARS-CoV-2 retain the capacity to infect and replicate in mammalian cells. Immunogenic compositions that include a live-attenuated SARS-CoV-2 and methods of eliciting an immune response against SARS-CoV-2 in a subject are also described. Further disclosed are a collection of reverse genetics plasmids that include the complement of the recombinant genome of the live-attenuated SARS-CoV-2 and methods of producing a live-attenuated SARS-CoV-2 using the reverse genetics plasmids.

The present invention relates to the use of an immunogenic composition that comprises a porcine circovirus type 3 (PCV3) antigen for treatment of several clinical manifestations (diseases). Preferably, the clinical manifestations are associated with a PCV3 infection.

The invention pertains to a combination of a first vaccine comprising anon-replicating immunogen of porcine circovirus type 2 (PCV-2) and a non-replicating immunogen of Mycoplasma hyopneumoniae, and a second vaccine comprising a live attenuated porcine reproductive and respiratory syndrome (PRRS) virus, for use in prophylactically treating a pig against an infection with PCV-2, an infection with Mycoplasma hyopneumoniae and an infection with PRRS virus, by associated separate injection of the first vaccine and the second vaccine into a tissue of the pig at a first and a second injection site respectively, wherein the first and second injection sites are at most 5 cm apart from each other.