Liam Mannix17:40, Jul 08 2021
Chinatopix/AP
Researcher Shi Zhengli works in a lab of the Wuhan Institute of Virology in Wuhan in central China’s Hubei province.
Leading virologists have released a paper setting out their strongest case for Covid-19 emerging from an animal and pushing back hard against the theory that it leaked out of a Chinese laboratory. While the exact animal that harboured Covid-19 has not yet been found, there is strong evidence for an animal origin argue the authors, who include Australian Nobel laureate Professor Peter Doherty. “Although it is impossible to fully exclude a lab accident, there is no evidence at the moment that the virus escaped from the Wuhan Institute of Virology,” said lead author Professor Edward Holmes, a virologist at the University of Sydney.
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To achieve herd immunity, we would need to cut the R value by between 45 and 55 per cent, said Associate Professor James Wood, a University of NSW vaccine modeller and member of the federal government’s Australian Technical Advisory Group on Immunisation.
“That would theoretically be achievable with a vaccine with 70 per cent efficacy against transmission but would require in particular high coverage in the 18-35 year group, which appear to contribute a greater fraction of transmission.”
But there is now a complicating factor that did not exist six months ago: the emergence of B.1.1.7, a variant of the coronavirus that is substantially more transmissible.
.
To achieve herd immunity, we would need to cut the R value by between 45 and 55 per cent, said Associate Professor James Wood, a University of NSW vaccine modeller and member of the federal government’s Australian Technical Advisory Group on Immunisation.
“That would theoretically be achievable with a vaccine with 70 per cent efficacy against transmission but would require in particular high coverage in the 18-35 year group, which appear to contribute a greater fraction of transmission.”
But there is now a complicating factor that did not exist six months ago: the emergence of B.1.1.7, a variant of the coronavirus that is substantially more transmissible.
On Tuesday, the Australasian Virology Society confirmed to
The Age and
The Sydney Morning Herald that it supported an immediate pause in plans to roll out the AstraZeneca vaccine until research proved it was effective enough to achieve herd immunity.
But following a furious internal debate, the president of the virology society contacted
The Age and the
Herald late on Tuesday evening to say it had changed its position and no longer opposed the rollout of the vaccine.
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When asked why the society was changing its official position at the last moment, its president, Professor Gilda Tachedjian, said: “That’s for us to know and you to find out.