Our FLOVID-20 team released a new research preprint showing that Rhesus Monkeys vaccinated with FLOVID-20 were free of pneumonia-like infiltrates characteristic of SARS-CoV-2 (COVID-19) infection and presented with lower viral loads relative to controls. It is submitted for peer review and publication.
Background Persistent transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has given rise to a COVID-19 pandemic. Several vaccines, evoking protective spike antibody responses, conceived in 2020, are being deployed in mass public health vaccination programs. Recent data suggests, however, that as sequence variation in the spike genome accumulates, some vaccines may lose efficacy.
Methods Using a macaque model of SARS-CoV-2 infection, we tested the efficacy of a peptide-based vaccine targeting MHC Class I epitopes on the SARS-CoV-2 nucleocapsid protein. We administered biodegradable microspheres with synthetic peptides and adjuvants to rhesus macaques. Unvaccinated control and vaccinated macaques were challenged with 1 x 108 TCID50 units of SARS-CoV-2, followed by assessment of clinical symptoms, viral load, chest radiographs, sampling of peripheral blood and bronchoalveolar lavage (BAL) fluid for downstream analysis.
Results Vaccinated animals were free of pneumonia-like infiltrates characteristic of SARS-CoV-2 infection and presented with lower viral loads relative to controls. Gene expression in cells collected from BAL samples of vaccinated macaques revealed a unique signature associated with enhanced development of adaptive immune responses relative to control macaques.
Conclusions We demonstrate that a room temperature stable peptide vaccine based on known immunogenic HLA Class I bound CTL epitopes from the nucleocapsid protein can provide protection against SARS-CoV-2 infection in non-human primates.
The peer reviewed journal Vaccine has published the results of a mouse study demonstrating efficacy of the Company’s Ebola vaccine. The article describes how Flow Pharma used the same approach to design FLOVID-20 (FlowVax COVID-19), now undergoing pre-clinical testing for protection against SARS-CoV-2, the virus that causes COVID-19.
“Our article published today shows that a single injection of our Ebola vaccine provided 100% protection for mice exposed to Ebola virus” said Charles Herst, Ph.D., Chief Science Officer, Flow Pharma and first author on the article. “By relying on killer T-cells rather than antibodies, FlowVax Ebola is able to attack the nucleocapsid protein located at the center of the virus where antibodies cannot reach. We are taking the same approach with FlowVax COVID-19.”
“As a virologist interested in how the immune system reacts to viral infections, I think it is very interesting that people who previously survived Ebola and SARS-CoV-1 outbreaks were found to have killer T-cells targeting the nucleocapsid protein for those two different viruses” said Tom Hodge, Ph.D., former CDC Laboratory Director, now Flow Pharma Scientific Advisory Board member and article co-author. “Flow Pharma is now conducting pre-clinical testing for FlowVax COVID-19 which is designed to attack the nucleocapsid protein on SARS-CoV-2, the virus that causes COVID-19. By doing this we are trying to mimic the immune system response of the survivors of the SARS-CoV-1 outbreak in 2003.”
“Flow Pharma has been developing T-cell vaccines for immuno oncology and infectious disease applications using the FlowVax vaccine platform for over a decade” said Reid Rubsamen, M.D., CEO, Flow Pharma and co-author on the article. “We are happy to be using our FlowVax vaccine platform to address the new threat posed by SARS-CoV-2, the virus that causes COVID-19.”
Flow Pharma today announced that researchers at the University of Texas Medical Branch at Galveston (UTMB) will begin testing Flow Pharma’s FlowVax-based COVID-19 treatment candidate by challenging nonhuman primates with SARS-CoV-2, the virus that causes COVID-19 in humans, after the animals are vaccinated this month with FLOVID-20. FlowVax biomedicines utilize Flow Pharma’s patented Size Exclusion Antigen Presentation Control (SEAPAC(TM)) technology based on the benefits of making vaccine microspheres the same size as human white blood cells.