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Inhaled Vaccines

Dr Anushi Rajapaksa

Anushi Rajapaksa remembers the moment that launched her career. She had just completed a successful experiment using a new technology that showed a liquid vaccine could be inhaled, rather than injected.

The experiment, using one of the most fragile vaccine types, showed that the particles survived the transformation from liquid to an aerosol mist. This was a potentially new, non-invasive and pain-free way to deliver vaccines – and would be especially useful for newborn and premature babies, and people in developing countries.

The nebuliser technology uses a microchip, similar to that found in a mobile phone, but modified to incorporate fluid. Sound waves from the chip converted the liquid into an inhalable mist. The challenge was to ensure the vaccines survived the process and remained intact to preserve their biological function.

When the experiment worked, Anushi says the nebuliser’s potential seemed limitless. “Vaccination is just one option. There’s no reason why it couldn’t also be used for stem cell delivery and other therapeutics via inhalation as well.”

Until then, the research had been a high-risk side project to her PhD that she was encouraged to explore if she had ‘spare time’, but it quickly became the new focus. “It was this amazing discovery we didn’t envisage,” Anushi says of the research. “That was the beginning of everything - my whole career.”

The discovery earned her Engineers Australia’s Young Biomedical Engineer of 2010 award.

While the matchbox-sized device has wide-reaching potential, Anushi’s research with Associate Professor David Tingay and the neonatal research team is to pursue its use to deliver immunisations non-invasively.

It would be especially beneficial and cost-effective to deliver vaccines to children in the third world countries, she says. “The nebuliser technology can be made portable and only requires a few batteries for operation. There is huge potential for this work to be used for mass vaccination programs especially in the developing countries with limited resources.”

The nebuliser would deliver droplets containing the vaccine that could then be inhaled to be deposited on the deep surfaces of the lungs. Influenza is one of the first targets of the technology.  Most germs enter the human body via the lung and it would be important to have a strong first line of defence. Anushi’s research is testing whether delivering immunisations directly to the lungs is superior to having a flu jab. “I don’t envision that injections will be a thing of the past; but rather it will be about giving people an alternative method of vaccination.”

She is also very keen on the potential for immunisations to be delivered via inhalation to very premature babies.

“Many premature babies have poor lung development. This should be a priority so we safeguard them from severe respiratory illnesses quite early on in their life.”

Anushi has become a mother herself since joining the Institute – her children are aged nine months and three. They have helped guide her research. “Now that I’m a mother I feel very strongly about addressing the needs of premature babies – they are the ones who really need this protection. These children have their whole lives ahead of them and you want to give them the best start to life.”