Last month the World Health Organisation (WHO) announced plans that could help fast-track the clinical development of two Ebola vaccines trialled by GlaxoSmithKline and NewLink, as well as a number of experimental vaccines by firms that include Crucell, Profectus BioSciences and J&J, in the wake of the ongoing Ebola crisis in West Africa.
But unless pharma puts its hand in its pocket it could be the end of the line for researchers at The University of Texas at Austin, who, after seven years of development with funding from an NIH grant, have created the only non-injectable vaccine platform with proof to date that a single dose could prevent future outbreaks of Ebola.
“We’re at a plateau right now - our money to support this project has run out and has left us in limbo,” lead researcher on the project Maria Croyle told in-Pharmatechnologist.com at the recent AAPS annual meeting. “We have something great, we’d like to get it to the people that need it the most but we just need money and backing to take this into clinical trials.”
The good news for Croyle and her colleagues is results in animal models have shown a single intranasal dose to be long-lasting, and at the beginning of this month a paper was accepted into the Journal of Molecular Pharmaceutics, bringing validation of the platform to the scientific community.
Despite setbacks including a wait for NIH approval of a Canadian facility and working at a biosafety level IV lab in Galveston, Texas, which had to be closed several months each year to ensure safety during hurricane season, Croyle said “this ended up being one of the only studies out there where all the animals that got the nasal spray survived, even after a long gap between getting the vaccine and being exposed to Ebola, and that’s what we’re presenting here [at AAPS].”
Formulation
The vaccine consists of a gene sequence for the glycoprotein that covers the outside of the virus, and it is targeted against Ebola Zaire, the strain that is in the current outbreak, she explained.
“The vector itself is a recombinant adenovirus which is very good at infecting cells and the concept we came up with to put into the virus is very quick acting and within 24 hours it delivers a lot of this Ebola glycoprotein, which is excellent as you get a quick and strong immune response against it.”
“[For this vaccine] the things we use are relatively simple things, like sugars and detergents that stabilise the virus for a significant amount of time,” she said. Secondly, “we worked on the delivery device, creating a syringe-type spray that doesn’t disrupt or destroy our vaccine because we need an intact virus particle to infect cells.”
Seven year itch?
Administering the vaccine nasally brings a number of advantages over the other vaccines in development, including safety, compliance and cost, but we asked Croyle whether there were formulation issues that may complicate development of an expedited vaccine.
“There would be an extra hindrance if you were formulating a nasal vaccine starting at square one. However, we did all the groundwork that dealt with that complexity over the last seven years including testing toxicity on top of efficacy and immunology tests on primates.
“So we’ve done a lot of that scout work which I think other people and companies don’t have time for right now.”
While the race to bring a vaccine to market is underway, Croyle added it is critical to ensure safety, especially in developing countries. “You want to be the first to get something out there that works, but the minute there is a side effect and something goes wrong you have lost all trust.”