David, you're pretty good with stats - as demonstrated.
Masks have had a reasonable role in reducing the spread of the virus. They say the risk of transmission is reduced by approx.. 60% when they are worn.
Can you calculate the benefit of a 60% reduction in transmission risk for 6 million people wearing masks when there is next to zero cases?
That 60% number is based on a paper outlining an experiment done on Hamsters in lab conditions.
The experiment strung up masks between cages, and gauged the number of infected hamsters during a fixed time period, compared to a control with no mask strung up.
It was also conducted in two ways, one in which the infected hamster cage had the mask, the other in which the uninfected hamster cage had the mask.
60% refers to the situation in which the infected hamsters were 'wearing' the mask.
This is not a number that can be applied to epidemiological predictions. It is simply the outcome of an experiment done in lab conditions showing that
in hamsters, an effectively used mask can reduce transmission.
There is very minimal evidence to show the effectiveness of mask use at an epidemiological level. The problem is that there are so many extraneous variables in trying to analyse the data, as masks are rarely used in isolation as the only preventative measure. The logic is basically that, because they can do something when used properly under the right conditions, with the right people wearing them, it
should be having an impact.
My biggest concern throughout this whole year, which I documented here at the start of all this, is that people will assume that wearing a mask magically protects them. I.e. "I can go out with a cold, I was wearing a mask" "We don't need to physically distance, we were all wearing masks".
It's certainly not possible to just add a 60% reduction in transmission to the current numbers.
I don't recall it being explicitly stated anywhere, but my belief was masks are less about the wearer catching the virus, and more to do preventing the wearer from spreading the virus. It basically forces everyone to cover their mouth when they cough or sneeze.
So despite people not wearing them correctly, or removing them without washing hands/sanitizing, they'll still have an effect in preventing the spread.
Personally, I'm happy to stick with mask wearing everywhere for the time being but understand some peoples frustration with them being required outdoors.
Different masks offer different levels of protection, but the standard surgical masks that most people are wearing are most effective when the infected person wears them. This is probably true for all masks, but the actual medical grade masks probably offer more protection to the uninfected person as well.
So there is proof they prevent further outbreaks? Unfortunately its a blanket decision not supported by the experience in other states nor by any evidence of widespread outdoor transmission.
And how many people are using them correctly?
An expert explains why scarves and masks with holes cut in them are less effective at preventing the transmission of coronavirus
www.theguardian.com
It's a misunderstanding of the basic scientific method to ask for 'proof', before applying evidence based practice.
Proof is not a scientific word. It's the realm of mathematics and the legal system.
All scientists look for is evidence that either supports or refutes a hypothesis, then they construct the best models they can on that evidence to be challenged again. We don't need proof of mask effectiveness to have evidence that they can be effective, and therefore take action based on that evidence.
Often in Science, we're not following the proven path, just our best guess at the time until evidence suggests it's a bad one. At the moment, based on the current evidence, universal mask use makes sense as a precautionary measure. But as the situation changes, the precautionary measures we take will change, but that's more of an ethical discussion than a scientific one.
Massive test numbers as well; over 20,000!
