The University of Hawaii Manoa has received a $6.4 million federal grant to continue development of a promising Ebola vaccine.

Other Ebola vaccines are also being developed around the world, but this one would be thermostable, or heat-resistant, and doesn’t have to be refrigerated. It would also protect against the three most common strains of Ebola virus, while other vaccines being developed can only fight one type.

Thermostable vaccines are easier to produce, store and transport because they don’t have to be kept at a lower temperature.

No Ebola vaccines are on the market yet, and the others under development must be kept cool and are based on weakened, live viruses with the ability to replicate. This vaccine would be unable to infect humans because it doesn’t use the whole viral protein and cannot replicate.

The $6.4 million awarded to UH by the National Institute of Allergy and Infectious Diseases will be distributed over five years. A private company, Hawaii Biotech, will receive $1.5 million to provide proteins for the vaccine and aid in the development stage. Another $700,000 will go to Soligenix, a biopharmaceutical company that specializes in creating thermostable vaccines.

A Stronger Vaccine

The Ebola vaccine under development is “trivalent,” which means it would have the ability to counteract the three most common Ebola virus strains, said Hawaii Biotech CEO Elliot Parks. Four of the five types of Ebola virus can infect humans.

This vaccine could be more easily transported to other parts of the world that might not have readily available refrigeration.

“I have no doubt whatsoever that we can manufacture (the vaccine),” Parks said, adding he’s confident it will be safe. “The question is, when we go into the clinic, how effective will this be in humans?”

Hawaii Biotech patented the antigen, which causes an immune response, for the trivalent vaccine and licensed UH with the ability to use it.

UH’s project is spearheaded by Axel Lehrer, an assistant professor in the Department of Tropical Medicine, Medical Microbiology and Pharmacology at the John A. Burns School of Medicine.

Lehrer has worked at UH for about four years and previously worked for Hawaii Biotech. He’s been working on this Ebola vaccine for 15 years.

Now, the vaccine’s formula is being refined so studies can be completed on animals through a partnership with the University of Texas Medical Branch in Galveston. Animal testing shows whether the vaccine can cause an immune system response and protect from disease.

Lehrer said a vaccine against three Ebola viruses and with a long shelf life could be readily accessible in the event of an outbreak.

Vaccines that rely on live viruses don’t survive long when stored at a high temperature. Producing a heat-resistant vaccine may cost more initially, but transportation is cheaper since refrigeration isn’t necessary.

The current formulation can be stored for three months at temperatures up to 105 degrees Fahrenheit, Lehrer said. Tests on non-human primates have shown three doses of the vaccine can provide almost total protection from Ebola.

Eventually Lehrer hopes to further refine the vaccine formula and test it in humans to determine whether it can protect them from the three most common types of Ebola — and possibly the fourth, less common type that can also infect humans.

He said it’s all about determining, “How far can we push the envelope? How many of these diseases can we prevent against?”