The rapid and global spread of the swine flu has shown how the world needs a new and “cross-reactive” approach to tackling viruses, an eminent Australian immunologist says.
Laureate Professor Peter Doherty, from the University of Melbourne, says the a(H1N1) virus showed how a newly emerged flu variant could now spread person-to-person globally, aided by international travel, in just months.
Prof Doherty, who won a Nobel Prize for his joint work to discover how the immune system recognises virus infected cells, said this was “very, very quick” and it left precious little time to react.
“It takes at least six months to get a new vaccine out there, so unless its something that is already in the pipeline you may not have vaccine ready … in fact you almost certainly won’t,” Prof Doherty told AAP.
“If we could design something that was cross-reactive we could stockpile it, the trouble is you cannot predict what flu will do.”
Modern vaccines work by carrying an inert version of a virus that, once inside the human body, prompts the creation of a store of antibodies which combat the real bug should a person become infected.
These vaccines were “very specific”, Prof Doherty said, and needed to be updated every year to match the latest mutated versions of several different strains of the circulating flu virus.
“The problem with influenza is that it is constantly throwing off different variants – it has very poor proof-reading in its genome,” Prof Doherty said.
The key to creating a stockpile-able vaccine that would be effective against all versions of the flu, he said, was to find elements of the virus’ make-up that were shared by all variants.
Research was now under way looking for features that “not only are they common, they can’t readily change without compromising the fitness of the virus”, along with a mechanism that would prompt the immune system to attack.
Prof Doherty said several potential targets had been identified, although whether a broad-acting vaccine was a technical possibility would not be known for “at least a decade”.
“It’s not certain we can … but we need to try, whether we are going to get a better solution is not clear,” he said.
If the work is a success it could revolutionise not only the global response to influenza.
It could also provide new insights into combating another of the world’s widely circulating viruses, which has a high rate of mutability that has allowed it to evade efforts at a vaccine.
“We have exactly the same problem with the AIDS virus,” Prof Doherty said.
“The only way we’re ever going to knock that is if we can make a cross-reactive antibody response, because the thing is just so variable.”
Prof Doherty spoke at the opening of the OzBio 2010 conference, a Melbourne-based gathering of 2000 scientists from around the world this week.
OzBio 2010 is a combination of the conferences of the International Union of Biochemistry and Molecular Biology, the Federation of Asian and Oceanian Biochemists and Molecular Biologists, and ComBio, Australasia’s premier broad-based biological sciences meeting.