Scientists have produced a single dose Ebola vaccine shown to provide primates with long-term protection from the deadly disease. What is most promising about the development is the delivery method, with the vaccine administered through the nose and lungs, mitigating the associated risk of spreading the disease through infected needles.

While other Ebola vaccines are currently under development, the team led by Maria Croyle, Professor of Pharmaceutics at the University of Texas, has focused on methods that don't require an injection. They say this may serve to reduce the chances of accidental transmission through unsafe handling of medical waste.

The team tested a novel formulation of an Ebola vaccine on three macaques, delivered through the nose and a catheter into their airways. They were then exposed to the disease four months later but did not fall ill, indicating an effective vaccination period of at least 21 weeks.

But because specialized equipment and training is needed to administer the vaccine in this way, the team says further work is required before the method is implemented in large-scale treatments.

The research was published in the journal Molecular Pharmaceutics.