A cure for Ebola? Developing a needle-free vaccine for long-term protection
The current Ebola outbreak in West Africa has killed over 10,000 people so far, but finally a cure is on the horizon. For the past seven years, Dr Maria Croyle and her team at the University of Texas have been working on a vaccine that offers long-term protection against the deadly virus, and the latest tests show that it has a 100 per cent success rate in primates.
The vaccine, which is inhaled through the nose instead of injected, could enable fast control of future outbreaks and revolutionise the way life-saving drugs are produced. It’s just one of the incredible cutting-edge discoveries explored in the new National Geographic Channel series Breakthrough. We spoke to Dr Croyle to find out more about her work and what the future of vaccines has in store.
How did you develop the Ebola vaccine?
I was contacted by two scientists who were First Responders to many of the Ebola outbreaks and very interested in my project to develop a needle-free vaccine. I spent two months in their laboratory, where they had the genetic material for Ebola, and we developed the vaccine, which is essentially a cold virus called the adenovirus.
We took out the DNA from the cold virus that allowed it to replicate and make us sick, and replaced it with the sequence of the protein that covers the outside of the Ebola virus. We figured if we could get an immune response against that protein, the virus is pretty much dead in the water and can’t make someone sick.
Why does it take so long to develop a vaccine?
It’s great to rush something out to the people that need it, but if there is any chance that it may not be safe, that could completely destroy a vaccine that may otherwise be very good. So that’s why there is something called the ‘three animal rule’. Essentially you have to test the vaccine in three animal models that reflect the human disease. Throughout the whole process, not only did we look for the fact that there’s a good immune response, we also looked for toxicities that could cause a problem.
What are the benefits of a needle-free vaccine?
A lot of places affected by the Ebola outbreak are very isolated villages where they are not used to people that aren’t part of their culture. It isn’t acceptable for someone outside of that to go after them with a needle. Plus, the nasal spray alerts the immune system to the areas where one would be exposed to Ebola – through cuts or abrasions in the skin – much faster than an injection does.
What stage is the vaccine at right now?
It’s ready to go. We’re currently in the process of talking with two major companies that have the resources to produce it on a large scale and can really help to get it to the people who need it most. We really hope within the next year it will be available.
How do you think the process of producing vaccines will change in the future?
The way we stabilise the vaccine is unique and we think it will change the way certain vaccines that need refrigeration are produced. In our studies with mice and guinea pigs, we found that if we placed the vaccine under the tongue, it seemed to work really well. So we stabilised the vaccine in this thin, flexible film that almost looks like a fruit rollup. This way, we found that we could store it at room temperature for at least three years. We could then simply put it in an envelope, ship it to where it was needed and once it got there, add water to the sheet of vaccine and in minutes it could be used as a nasal spray.
Dr Maria Croyle appears in the ‘Fighting Pandemics’ episode of Breakthrough, which airs on Sunday 8th November at 10pm on National Geographic Channel.
Pick up a copy of How It Works Issue 79 to read our fascinating interview with Breakthrough scientist Professor Henrik Ehrsson, whose body-swapping techniques feature in the ‘More Than Human‘ episode!
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