Polynucleotides encoding SARS-COV-2 antigens and use thereof in the medical field as vaccines

1 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition comprising said polynucleotide or expression vector in combination with one or more excipients and/or adjuvants, wherein the polynucleotide comprises or consists of a sequence selected from:

SEQ ID NO:1 fused to the C-terminal of the tissue plasminogen activator (TPA) secretion leader sequence, said sequence SEQ ID NO:1 encoding an amino acid sequence consisting of the receptor binding domain (RBD) domain of the S1 subunit of the spike protein of the SARS-CoV-2 virus or of variants thereof;

a sequence having a percent identity greater than or equal to 80% compared to sequence SEQ ID NO:1, selected from SEQ ID NO:14, SEQ ID NO:15, and SEQ ID NO:21, alone or fused to the C-terminal of the tissue plasminogen activator (TPA) secretion leader sequence;

SEQ ID NO:2, which encodes an amino acid sequence consisting of the N-terminal domain (NTD) and RBD domains of the S1 subunit of the spike protein of the SARS-CoV-2 virus;

SEQ ID NO:3, which encodes an amino acid sequence consisting of the NTD, RBD, C-terminal domain 2 (CTD2) and C-terminal domain 3 (CTD3) domains of the S1 subunit of the spike protein of the SARS-CoV-2 virus;

SEQ ID NO:5, which encodes an amino acid sequence consisting of the spike protein of the SARS-CoV-2 virus; and

SEQ ID NO:4, which encodes an amino acid sequence consisting of the RBD domain of the S1 subunit of the spike protein of the SARS-CoV-2 virus, said domain being fused at the N-terminal end to the IgK leader sequence and at the C-terminal end to the Fc immunomodulating sequence.

2 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 1 , wherein said polynucleotide further comprises one or more sequences encoding one, more than one, or all of the domains selected from among N-Terminal Domain (NTD), C-Terminal Domain 2 (CDT2) and C-Terminal Domain 3 (CDT3) of the S1 subunit of the spike protein of the SARS-CoV-2 virus or of variants thereof.

3 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 1 ,

wherein the polynucleotide further comprises a sequence encoding a leader sequence.

4 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 3 , wherein the leader sequence is selected from the secretion leader sequence of the tissue plasminogen activator (TPA), of IgK, of growth hormone, of serum albumin, or of alkaline phosphatase.

5 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 1 ,

wherein the polynucleotide further comprises a sequence encoding an immunomodulating amino acid sequence.

6 . The polynucleotide encoding an amino acid sequence, the expression vector comprising said polynucleotide, or the pharmaceutical composition according to claim 5 , wherein said immunomodulating amino acid sequence is selected from a fragment crystallisable (Fc) region, profilin-like protein of Toxoplasma gondii (PFTG) or a functional fragment derived therefrom, the B subunit of the heat-labile toxin of Escherichia coli (LTB) or the tetanus toxin (TT).

7 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 1 ,

wherein the polynucleotide further comprises one or more sequences encoding one or more antigenic sequences of the SARS-CoV-2 virus other than those of the S1 subunit of the spike protein of the SARS-CoV-2 virus.

8 . A polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 1 ,

wherein said expression vector is selected from the group consisting of a plasmid, a bacterial plasmid, an RNA, a replicating RNA, an amplicon obtained by PCR, and a viral vector.

9 . The polynucleotide encoding an amino acid sequence, the expression vector comprising said polynucleotide, or the pharmaceutical composition according to claim 8 , wherein said viral vector is selected from adenovirus, poxvirus, vaccinia virus, fowlpox, herpes virus, adeno-associated virus (AAV), alphavirus, lentivirus, lambda phage, lymphocytic choriomeningitis virus.

10 . The polynucleotide encoding an amino acid sequence, the expression vector comprising said polynucleotide, or the pharmaceutical composition according to claim 8 , wherein said bacterial plasmid is selected from Listeria sp sp and Salmonella sp.

11 . A kit for the prevention and treatment of the disease caused by the SARS-CoV-2 virus, said kit comprising or consisting of: a) a polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition as defined in claim 1 ; and b) a system of administration by electroporation or another device for in vivo gene transduction.

12 . A DNA, RNA or protein-based vaccine comprising a polynucleotide encoding an amino acid sequence, an expression vector comprising said polynucleotide, or a pharmaceutical composition according to claim 1 .