An Australian biomedical engineer, Mark Kendall, is poised to revolutionize the way life-saving vaccines are delivered, dramatically lowering the cost of immunization in the developing world and dispensing with the needle and syringe.
An invisible miniature landscape sown with a forest of microscopic spikes is emerging as one of the world’s great hopes for helping spare the lives of the 17 million people who still die each year from infectious disease.
Devised by Australian biomedical engineer Mark Kendall, the “Nanopatch” promises to revolutionize two centuries of vaccination by placing a tiny dose of inoculant just under the skin painlessly, with exquisite precision and more than 100 times the efficacy of needle delivery.
Building on trials funded by his Rolex Award, Kendall intends to ensure the developing world receives the latest and best vaccines far more quickly, cheaply and widely. “I have an absolute passion to deliver better vaccination to the low-resource regions of the world, without them having to wait years for it to trickle down from the developed world,” he affirms.
As a youngster growing up in the Australian state of Queensland, Kendall was obsessed with making mechanical things work better: “It’s like having a valve you can’t turn off,” he explains. The fascination with problem solving led him to a student career in engineering at the University of Queensland, helping develop hypersonic wind tunnels for testing vehicles to explore the planet Mars and, for a while, he seemed destined to become the proverbial “rocket scientist”. Then an appointment as lecturer at Oxford University in the U.K. brought him in touch with some of the world’s most brilliant biological minds – and he began to ponder the applications of rocket science to human health.
A Eureka moment
His first idea was a stroke of genius: the use of a tiny rocket “gun” to fire powdered vaccine into the skin at 2000km/h. Known as PowderJect, this innovation led to a new research centre and a technology sale by Oxford University worth US$400 million to pharmaceutical giant Pfizer. But Kendall’s questing mind was unfulfilled: he wanted to achieve greater precision and efficacy, by inserting vaccine at the exact position in the skin for optimal protection. Doodling in a lecture one day in 2003 while attending a scientific conference in Sydney, he envisioned an array of micro-spikes of precisely the right length and spacing: it was a Eureka moment. The Nanopatch was conceived – but the technical and developmental challenges were formidable.
Later that year, Kendall had a second flash of insight: “I came to the self-awareness that this idea was truly important – and that it was going to work. From then on, I was in the zone,” he recalls. “I utterly immersed myself in the project.”
To mass produce such a tiny device, Kendall raided the latest computer-chip technology, employing a stream of ions to blow away the surrounding silicon matrix and leaving a forest of tiny spikes barely a tenth of a millimetre tall. But they were just spikes, not hollow needles, so Kendall used his fluid mechanics expertise to devise a gas-jet method to powder-coat the spikes with vaccine ingredients – with success that far exceeded his hopes. Coupling this with new insights into the mechanical properties of human skin, he was able to create a device that can deliver a minute dose of dry vaccine right where it is needed.
Safer and cheaper
The Nanopatch has the potential to significantly improve the reach of vaccines to those who need them most. Expected to be painless, it only has to remain in place for a minute or so to immunize the recipient. It can be cheaply manufactured from silicon or polycarbonate for much less than US $1dollar and uses less than 1 per cent of the standard vaccine dose – a major cost saving. It is thus set to be far cheaper and safer than the 160-year-old needle-and-syringe that it promises one day to supplant. Above all, it is stable in hot temperatures and does not depend on the long, costly and vulnerable “cold chain” of refrigeration required to deliver today’s vaccines. In remote areas, maintaining this cold chain can devour 80 per cent of vaccination campaign funds. “Even in places where vaccination is happening, people still die due to failures in the cold chain which render the vaccines inactive,” he explains. “The Nanopatch overcomes that concern because it does not need refrigeration.”
Returning to Australia in 2006 as a professor at the University of Queensland’s Australian Institute for Bioengineering and Nanotechnology (AIBN), Kendall laboured to perfect his ideas, test the patch in animals and humans and raise development capital. Trialled on laboratory mice, the protective results proved spectacular. In 2011, he co-founded a company, Vaxxas, with an investor syndicate, to develop the Nanopatch worldwide.
But one thing troubled his conscience. “I knew that it takes years, even decades, for modern vaccines to reach the under-resourced regions of the world – yet most of the deaths from infectious disease occur there. I also knew that state-of-the-art vaccines are often far too expensive for mass campaigns in developing countries.”
To fast-track delivery of new vaccines in poor countries, where commercial funding is hard to obtain, he applied for a Rolex Award for Enterprise, to conduct a field trial in nearby Papua New Guinea where medical and climatic conditions mirror much of the developing world. This will follow the first human trials of the patch in Brisbane, Australia, and will involve “blank” Nanopatches (without vaccine) in human volunteers. Its aim is to assess the usability of the patch and applicator under developing-country field conditions.
Next, Kendall plans to run an international trial using the human papilloma virus (HPV) vaccine, which protects women against cervical cancer: this disease claims 270,000 lives a year and is the leading cause of cancer deaths among women in the developing world. The HPV vaccine is one of a new generation that is unaffordable in developing countries – but could become affordable with the low-cost Nanopatch. Beyond that, Kendall sees diseases such as influenza, malaria, West Nile virus, herpes, chickungunya and even HIV as promising targets.
Published in 2012