ABC Science: vaccines combine to create deadly virus

[Guest guest]

Olala ! Let me venture a guess that this won't make front page news… http://www.abc.net.au/science/articles/2012/07/13/3545318.htmAustralian scientists have found that two different vaccines used to control an infectious disease in chickens can recombine

to create new lethal virus strains.

The research, to be published today in the journal Science, has prompted authorities to review vaccine use in animals.

But the scientists, from the University of Melbourne,

say the findings are not only important for vaccines in chickens, but also for any vaccine which might be able to multiply - including those used in humans.

Chicken respiratory virus ILT can lead to birds dying in a pool of bloody mucus, but vaccines that were meant to protect them have instead led to their deaths.

Dr Joanne Devlin, a lecturer in Veterinary Public Health-Epidemiology

at the Asia-Pacific Centre for Animal Health, says the deaths were caused when two vaccines used to treat the virus combined.

"These new strains were formed by recombination from the different vaccine strains and that they were actually more virulent than the vaccine strains that gave rise to them," she says.

"This is something we've never before seen before in the field."

Live vaccines, where a weaker version of the virus is introduced to allow the immune system to build up its own defences, are quite commonly

used for animals and humans, and include polio, measles, mumps, rubella, chicken pox and rabies.

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