Written by Karl Beidatsch Tuesday, 26 May 2009 00:00
The research team, headed up by Professor George Milne, is using a virtual model of the city of Albany to plot the effects of government policies and actions on viral spread.
Prof Milne’s conclusions from the study are that, in the event of an outbreak, immediate social distancing measures are vital.
Social distancing involves school closure, home isolation, reduction of workplace numbers and reduction in community contact.
The team ran the simulation multiple times, changing the infectiousness of the disease and altering the time when social distancing measures were introduced.
In the worst case scenario, delaying these measures by just two weeks from the introduction of the first infectious individual can see the illness rate reach as high as 35 percent of the population, with important implications for possible actions in the case of a swine flu pandemic.
“I think Mexico’s done the right thing,” says Prof Milne.
“They’ve been quick and draconian. Of course you don’t know the transmissibility or the mortality rate of the strain when it first comes out, so this overkill is probably a good strategy.
“Once you actually know what the virus is doing, you can start to relax.”
However, Prof Milne says that these social distancing measures are not a solution in themselves.
Particularly, he wants to see an increase in the use of two-stage vaccines.
When a new virus appears, this form of vaccine comes in two doses: one primer to prepare the immune system, and then a booster shot tailored specifically to the virus. There is a five week delay between the first and second injections, meaning that in the event of a viral outbreak it will take a minimum of six weeks to achieve ‘herd immunity’.
Herd immunity is the point when enough individuals have been immunised that the virus will be effectively contained without need for quarantine.
Prof Milne says that if generic primer shots were created that could provide basic immunity against the most common strains of influenza, then they could be included in the yearly flu vaccine.
“The detailed tests have said that the primer lasts for at least six months but there is some other evidence where people have primed for H1N1 and boosted it seven years later and it works.
“If that proves to be the case, then that’d be fantastic, because logistically you could get the primer into a vast amount of the population, then manufacture the tailored booster when a virus appears and roll it out.”
