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We are developing vaccines to protect the public from life-threatening diseases. Our proprietary vaccines are based on parainfluenza virus 5 (PIV5), also known as canine parainfluenza virus. We insert a gene encoding an antigen of interest into the PIV5 genome.

When one of our vaccine vectors is introduced to a host, it undergoes several rounds of self-limited replication, inducing robust immune responses with as few as one dose.

Robust Immune Responses

In preclinical studies, we have shown that our vaccines robustly produce three forms of immunity:

    1. Cellular immunity: Cellular immunity is essential for fighting off viral infections. While antibodies can slow down a virus, some cells will still become infected, so cellular immunity is needed to eliminate those cells. Our vaccines regularly generate robust cytotoxic T-cell responses, a critical component of cellular immunity.

    2. Humoral immunity: A key defense against future infections, humoral immunity produces antibodies in the blood. The efficacy of vaccines is most easily evaluated by the humoral antibody response they generate, and our PIV5-based vaccines produce a strong antibody response with a single dose.

    3. Mucosal immunity: Comprised of secretory antibodies at the mucosal surface, mucosal immunity is the first line of defense against infection, blocking pathogens at their site of entry into a host (e.g. the mucosal lining of the respiratory tract). Our intranasal vaccines generate mucosal immunity because they are introduced through the nasal mucosa; injected vaccines do not.

Needle-free delivery

PIV5 is a respiratory virus, so our vaccines are "born intranasal". Delivered as a spray in the nose, without injections, our vaccines will facilitate broad delivery not only to pediatric and other needle-hesitant populations, but also in parts of the world where healthcare professionals are scarce.

Long track record of safety

For over 50 years, PIV5 itself has been used as part of a canine distemper (kennel cough) vaccine. Dogs dosed (intranasally) with the vaccine will often sneeze, exposing veterinarians to PIV5, and they will continue to shed virus for a few days, often exposing dog owners to PIV5. Many people already have antibodies against PIV5, proof that they have been exposed to the virus.¹ Yet despite decades of such exposure, PIV5 has never been known to cause disease in humans.

Rapid and low-cost manufacturing

Because PIV5 replicates in self-limited fashion, a relatively small number of viral particles (compared with other viral vectored vaccines) is needed to make each vaccine dose. With a relatively small bioreactor, we can theoretically produce millions of doses per month of our vaccines. Conventional virally-vectored vaccines need manufacturing capacity measured in 10,000s of liters to produce a similar number of doses. This makes our PIV5 technology ideal for rapidly responding to emerging infectious threats, as well as for defending against existing ones worldwide.

¹ Chen et al (2012), Evaluating a parainfluenza virus 5-based vaccine in a host with pre-existing immunity against parainfluenza virus 5, PLOS One, 7:e50144. Like humans, dogs generate neutralizing antibodies against PIV5 from prior exposure, yet these do not interfere with the activity of a PIV5-based vaccine.