A Different Vaccine Approach

Traditional vaccines are reliant on a few primary approaches: empirically weakened Live Attenuated Virus (LAV), inactivated (killed) forms of the virus, or created from the pathogen’s individual protein components (subunit vaccines) through protein purification, recombinant technology methods, or a combination of both.

Vacunax takes a phylogenetic approach to identify key virus evolutionary elements that are target for recombinant modifications to produce a safe, host-range limited LAV (HR-LAV) vaccine. Vacunax identified phylogenetic information that codes for key structural elements of the transmembrane domain of arbovirus spike proteins which have evolved in length to span both the thinner invertebrate membrane, and thicker cholesterol containing vertebrate membranes. Removing specific amino acids from this transmembrane domain results in species restricted viruses which grow efficiently in insect cells, but produces very limited amounts of non-infectious (inactive) particles in vertebrate cells.

HR-LAV: The Better Vaccine Strategy

The goal of vaccination is to stimulate protective immunity while avoiding adverse events from the vaccine itself. Live Attenuated Vaccines (LAV), when possible and available, are the most complete and effective vaccines, for these activate both, antibodies and cell-mediated responses, and are the closest we can get from a natural infection without the disease.

However, past attenuation processes were unpredictable, not always applicable, and limited by safety concerns, primarily of which is reversion to wild-type virulence.

Although inactivated virus and subunit vaccines alleviate many of the safety concerns for LAV vaccines, in general they have poor immunogenicity, do not produce long lasting immunity, requiring multiple booster doses to sustain benefit, and thus are less efficacious than their LAV counterparts.

The Vacunax HR-LAV variants contain large genetic deletions, making reversion to wild-type virulence impossible. In the laboratory, and in animal trials, no wild-type reversions have been detected. As the non-infectious particles produced by SC-LAV in vertebrate hosts contain all the proteins of wild-type virus, they are found to stimulate both a robust and antigenically varied primary antibody response, as well as the full “wild-type” cellular response in vertebrate animals.

By fully mimicking the natural disease process the Vacunax HR-LAV vaccine technology provides immediate, sustained and long term protection from pathogenic virus infection.

Using this HR-LAV host range mutation strategy, Vacunax has produced vaccines for dengue (flavivirus), chikungunya (alphavirus) fever, and Zika virus, which have had very successful preclinical trials in mice and/or monkeys (ref). Vacunax can produce vaccines against any Arbovirus (insect vectored viruses) that contains a membrane bilayer, a group of viruses that cause over 150 zoonotic diseases in humans and in many domestic animals.