Many experts said that W.H.O. it must adopt what some call the “precautionary principle” and others call it “needs and values” – the idea that, even without definitive evidence, the agency should assume the worst of the virus, apply common sense and recommend the best possible protection .
"There is no indisputable evidence that SARS-CoV-2 travels or is significantly transmitted by aerosols, but there is absolutely no evidence that it is not," said Dr. Trish Greenhalgh, a primary care physician at the University of Oxford , in Great Britain.
"So for the moment, we have to make a decision in the face of uncertainty, and my God, it will be a disastrous decision if we get it wrong," she said. "So, why not mask for a few weeks, just in case?"
After all, W.H.O. He seems willing to accept the idea that the virus can be transmitted from surfaces without much evidence, she and other researchers noted, even when other health agencies backed down by emphasizing this path.
"I agree that fomite transmission is not directly demonstrated for this virus," said Allegranzi, the AU's technical leader in infection control, referring to objects that can be infectious. "But it is known that other coronaviruses and respiratory viruses are transmitted and shown to be transmitted by contact with fomitus".
The agency must also consider the needs of all its member countries, including those with limited resources, and ensure that its recommendations are mitigated by "availability, feasibility, compliance, resource implications," she said.
Aerosols may have a limited role in spreading the virus, said Dr. Paul Hunter, a member of the infection prevention committee and professor of medicine at the University of East Anglia in Britain.