• Vaccine Name: Marburg Virus Vaccine pVAKS-GPVM
• Target Pathogen: Marburg Virus
• Target Disease: Hemorrhagic fever
• Type: DNA vaccine
• Status: Research
• Host Species for Licensed Use: None
• Antigen: Marburgvirus Glycoprotein
• GP protein [Marburg marburgvirus] gene engineering:
  • Type: DNA vaccine construction
  • Description: pVAKS-GPVM DNA vaccine contains a gene encoding Marburgvirus glycoprotein.
  • Detailed Gene Information: Click Here.
• Preparation: To construct DNA immunogen, a nucleotide sequence encoding MARV glycoprotein (GP) (GenBank CAA82539.1) was used. Surface GP of the virus con- sisting of GP1 and GP2 subunits (170 and 46 kDa, respectively) linked by disulfide bonds was chosen as the immunogen for immunity development. This GP plays the key role in the tropism of the virus to the target cells. GP1 contains a receptor-binding domain, and numerous sugar residues; glycosylation sites are concentrated in the mucin-like domain (MLD) [8]. Anti-MLD antibodies do not play a role in the protective immunity against MARV [5]. The nucleotide fragment corresponding to the MLD (from 290Leu to 422Asn) was deleted from the MARV GP sequence. The gene in the plasmid pGH and primers for PCR were synthesized by the DNA Synthesis Company. The amplified PCR product corresponding to MARV GP without a MLD was cleaved with restriction enzymes AsuNHI and BseX3I (SibEnzyme) and the vector pVAKS was cleaved with restriction enzymes AsuNHI and PspOMI (SibEnzyme). Then, the restriction products were mixed and ligated using bacteriophage T4 DNA ligase (SibEnzyme) for 30 min at room temperature. Transformation of competent cells of E. coli strain NEB Stable (New England Biolabs) with ligation products was performed using the heat- shock technique. The presence of the insert was confirmed by restriction analysis and Sanger sequencing. DNA for immunization was prepared in 2 liters ofLB nutrient medium (lysogeny broth) supplemented with ampicillin sodium salt (Sintez) at a working con- centration of 25 μg/ml. Plasmid DNA pVAKS-GPVM for immunization of guinea pigs was isolated using an EndoFree Plasmid GigaKit kit (Qiagen) according to manufacturer’s recommendations. (Volkova et al., 2021)
• Immunization Route: Intramuscular injection (i.m.)

Guinea pig Response

• Vaccination Protocol: Intramuscular immunization of guinea pigs weighing 180-200 g was carried out 3 times with an interval of 28 days. The dose of the immunogen for both pVAKS-GPVM and negative control pVAKS was 600 μg per animal. 3 antigens were used: recombinant MARV GP, virus-like particles based on the recombinant vesicular stomatitis virus, and inactivated MARV [3](Volkova et al., 2021)
• Immune Response: When determining the neutralization titer of serum from guinea pigs against MARV, the sera neutralized the virus in titers from 1:20 to more than 1:40, exhibiting potent neutralizing activity (Volkova et al., 2021)
• Side Effects: The animals have no rash, but develop coagulation defects, including a decrease in platelet count and an increase in coagulation time. (Volkova et al., 2021)