COVID-19 Vaccine Prototype for Successfully Induced Systemic Serum IgG in Mice

MediciNova announced its intranasal SARS-CoV-2 vaccine prototype for COVID-19, using BC-PIV technology, successfully induced systemic serum IgG and mucosal IgA neutralizing antibodies against the S1 antigen (Ag) of SARS-CoV-2 in mice.

A mouse model study was conducted to assess systemic IgG and mucosal IgA antibody production against S1 Ag after intranasal vaccination with MediciNova’s BC-PIV SARS-CoV-2 vaccine prototype. We confirmed a high IgA antibody titer against S1 Ag in the nasal lavage fluid from mice given intranasal BC-PIV SARS-CoV-2 vaccine. We also confirmed that a high IgG antibody titer against S1 Ag was induced in mice serum.

Yuichi Iwaki, M.D., Ph.D., President and Chief Executive Officer of MediciNova, Inc., commented, "We are very encouraged that our intranasal BC-PIV SARS-CoV-2 vaccine induced high titers of systemic serum IgG and mucosal IgA neutralizing antibodies in a mouse model study. These successful results support the scientific and technical rationale of our intranasal vaccine in addition to similar success with BioComo’s BC-PIV RSV vaccine prototype. We look forward to reporting additional progress on our intranasal COVID-19 vaccine in the near future.”

BC-PIV, an innovative non-transmissible viral vector co-developed by BioComo and Mie University, is derived from the recombinant human parainfluenza virus type 2 (hPIV2). It is highly efficient in its ability to transfer multiple foreign proteins to recipients and has a strong safety profile as no secondary infectious virus is produced. BC-PIV is designed to display not only the gene but also the foreign protein itself on the surface and inside of the viral membrane. Therefore, it can carry the large membrane proteins of viruses and signal transduction receptors/ligand proteins on the viral surface. BC-PIV is able to carry the proteins that require a proper three-dimensional structure or multimeric structure while maintaining the structure. BC-PIV elicits good immunogenicity against antigen proteins without adjuvants. The BC-PIV SARS-CoV-2 vaccine prototype has been developed to include the specific SARS-CoV-2 antigen protein in order to express maximum antigenicity. The BC-PIV SARS-COV-2 vaccine can be developed as an intranasal vaccine in addition to an intramuscular injection because of its high affinity to nasal and upper respiratory tract mucosa, which is the same route of the natural infection of SARS-CoV-2. An intranasal vaccine is expected to induce local mucosal immunity.