Reseachers make influenza vaccine delivery breakthrough
Press release
6 October 2008
Researchers at the University of Melbourne have found a method of administering the flu vaccine that could prove crucial in the event of a flu pandemic
By delivering the flu vaccine directly into the lungs, researchers have been able to trigger a greater immune response than with conventional injections.
With the world expected to face an extreme shortage of vaccines in the event of a pandemic, this raises the possibility of existing stocks being used to treat far greater numbers of people.
The study revealed that by delivering a very small dose of vaccine with an adjuvant - a substance added to a vaccine to boost the immune response – into the lungs, the same level of blood antibodies were produced when compared with an injection of much larger amounts.
“One of the biggest problems the world would face in the event of a human pandemic flu outbreak would be our inability to produce enough vaccine in a very short period of time to protect the global population,” said Associate Professor Sutton from the University’s Centre for Animal Biotechnology (CAB) in the Faculty of Veterinary Science.
“Our results suggest that delivery via the lung may allow a much lower amount of vaccine antigen to be used, while inducing equivalent or perhaps even improved protection. This would mean more people would quickly be able to receive the vaccine.”
The research, which was published in the journal Mucosal Immunology and conducted in sheep, also showed that the method of pulmonary (lung) delivery produced approximately 1,000 times as many antibodies in the lung – where the influenza virus infects – than the injected vaccine.
The results of the study surprised even the scientists carrying it out, according to Associate Professor Sutton.
“When we did the first lung vaccination we were simply aiming to compare 15 micrograms [15 millionths of a gram] injected versus 15 micrograms via the lung with adjuvant,” he said.
“We thought the addition of adjuvant might allow some antigen reduction so we tested down to one microgram and this was so effective we ended up having to perform further studies.”
Through these, the team was able to determine that this method of vaccination induced strong responses with as little as 0.04 micrograms – 375 times less antigen than the current injected influenza vaccine.
“Additionally, the generation of functional antibodies in the lung could potentially help reduce the spread of the infection by neutralising the virus before it can be breathed out by an infected person.”
The project which also involved Dr Janet Wee, Associate Professor Jean-Pierre Scheerlinck and Dr Ken Snibson at CAB in the Faculty of Veterinary Science started six years ago.
The next major challenges are to explore technologies for efficient delivery of the vaccine to humans by aerosol and validate the findings in clinical studies.
For further information please contact the Marketing Manager, Faculty of Veterinary Science, University of Melbourne, Tel: 8344 7844 or email: vet-communications@unimelb.edu.au