By NewsDesk  @infectiousdiseasenews

Clinical-stage biotechnology company, Vivaldi Biosciences, announced positive preclinical data supporting further development of Delta-19, its combination vaccine for protection against COVID-19 and all strains of influenza. SARS-CoV-2, the virus responsible for COVID-19, is expected to become endemic and adopt a seasonal pattern, much like influenza. Delta-19 is designed to address the dual disease threats of Covid-19 and influenza with a superior approach for greater protection against both diseases.

Studies of Delta-19 in the ferret model showed that 100% of the immunized animals generated high titers of SARS-CoV-2 spike-specific neutralizing antibodies, and 100% of the immunized animals were protected against challenge with a wild-type strain of SARS-CoV-2. Importantly, immunized ferrets had negligible amounts of SARS-CoV-2 challenge virus in their noses and mouths, while the virus proliferated to high levels in the noses and mouths of control ferrets. These findings suggest the possibility of achieving sterilizing immunity with Delta-19, preventing replication of SARS-CoV-2 in the upper respiratory tract and transmission to other individuals.

Vivaldi Biosciences already has shown in clinical trials that the influenza vaccine component of Delta-19 is safe, immunogenic, and generates broadly cross-protective antibodies to diverse influenza strains. Delta-19 builds on Vivaldi Biosciences’ DeltaFLU universal influenza vaccine, which has been successfully evaluated in four Phase 1 and 2 clinical trials. DeltaFLU shows potential for universal protection against all influenza A and B virus strains, including drifted seasonal influenza strains and emerging pandemic strains.

“With these strong proof of concept data we are ready to advance our Delta-19 program toward clinical trials. We filed a patent application last year, and we are prepared to undertake an accelerated development program, employing our expertise in vaccine strain optimization and cell-based production, and ready access to BSL-3 facilities,” said Bill Wick, CEO of Vivaldi Biosciences.

Delta-19 and DeltaFLU are based on Vivaldi Biosciences’ Delta NS1 vaccine vector. Delta-19 is a chimeric SARS-CoV-2 Delta NS1 vaccine that expresses key immunogenic antigens of SARS-CoV-2 and influenza viruses. Upon intranasal administration, Delta NS1 vaccines rapidly induce the immune signaling protein interferon and IgA antibodies to neutralize viruses in the nasal passages. Interferon generates a self-adjuvant effect that activates CD4+ and CD8+ T cells and antibody-producing B cells for robust systemic immunity.

Delta-19 may provide important advantages over mRNA vaccines for Covid-19. Unlike mRNA vaccines, which are administered by intramuscular injection, intranasal administration of Delta-19 is needle-free and pain-free. Reactogenicity and side effects of mRNA vaccines may impair patient acceptance. In contrast, clinical trials Delta NS1 vaccines show only mild side effects in some recipients. The stringent and expensive cold chain requirements of mRNA vaccines will not apply to Delta NS1 vaccines.