Stopping the flu before it takes hold
Researchers have discovered a way to prime the immune system to potentially tackle respiratory infections before we get sick, and work is underway on developing a treatment
Staying ahead of the fast-changing influenza virus is an unending race for new vaccines. But what if instead of racing for the next vaccine we could simply put our immune systems on high alert in readiness to fight off whatever influenza, or any other infection, throws at us?
A team of researchers at a biotech company spun out of the University of Melbourne are zeroing-in on doing just that - using a compound that can prime immune systems to fight off respiratory infections before they take hold. And we can thank our six-legged cousins – insects.
Insects, unlike humans, don’t have an adaptive immune system that responds to specific infections, but they do have a primordial “innate” immune system that they developed as part of their evolution over 400 million years ago.
Insects have relied on their innate immune systems to fight infections for hundreds of millions of years. Picture: 100 million year old fossil of an insect being eaten by a spider preserved in amber. Picture: Oregon State University/Flickr
The good news is we’ve inherited aspects of this innate immune system which has been built on and extensively modified over evolutionary time. The innate system responds immediately in a generalised way to any infection and in so doing alerts the adaptive immune system to respond more specifically if needed. But because the adaptive system takes days to become fully effective, potentially allowing an infection to spread, a strong immediate response from the innate immune system is an enormous advantage.
Now Melbourne-based Innavac are developing a synthetic compound that University of Melbourne researchers discovered can temporarily put the innate immune system on a high alert ahead of any infection. That early warning is, potentially, enough to enable it to head off the likes of influenza and the common cold, before we even get sick.
“What we are developing would be a preventative,” says Professor David Jackson from the Unversity’s Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity who has founded Innavac after his lab team patented their discoveries.
“We don’t know what the next flu strain is going to be, or what the next rhinovirus (common cold) will be, but the drug we are working on would be something you could take to alert your innate immune system and protect you against any of these different strains of infections,” he says.
It works by temporarily putting the innate immune system into a state of readiness so that viruses or bacteria are killed as soon as they enter through the nose or mouth, and before it can reach the lungs. A drug based on the compound could be a potential lifesaver for vulnerable people like the elderly, asthma suffers and those with lung diseases, and could be taken at times when the infection risk is high, such as when travelling in confined spaces like areoplanes. It may also be able to provide protection against the onset of virulent new viruses such as bird and swine flu, without having to wait for a vaccine.
Further research work is needed to determine for exactly how long a dose would be effective, but at this stage it appears to provide protection in rodents for several days.
The researchers also need to establish how often a dose could be safely taken since any immune response involves inflammation, which if prolonged can cause other health problems. But so far the results are encouraging.
Banner image: A colourised human Natural Killer white blood cell that is part of the innate immune system. Picture: National Institute of Allergy and Infectious Diseases/Flickr