TL;DR – Don’t yaya papaya even if we are fully vaccinated.
Much has been said and written about how Mdm Ho Ching is such a serial poster on Facebook. Some media outlets have even counted the number of Facebook posts she puts up in a day. It can be anything ranging from 50 to 200 a day.
Most of her Facebook posts are merely resharing articles and links from an astonishingly diverse range of topics, from food recipes to local hideouts to science to animals to even more controversial topics like acceptance of LGBT. Mostly, she just reshares without any comments.
Occasionally she would indulge her followers and share a little poem she’s written. With the pandemic, she has been a lot more active in sharing original contents that she’s written. Sometimes it’s life hacks and tips to help us better deal with COVID-19. Sometimes it’s sharing behind-the-scenes of some of Temasek’s projects, usually COVID-19 related. Or, sometimes it’s clarifying the science behind the virus or the vaccines, or shedding light on the technology of things. Mighty interesting woman, if you ask me.
With the new clusters emerging, she’s put up a new and very useful post yesterday about masking up.
And she’s answered the question that’s on many people’s minds since day one:
Suppose we have a mask that is 90% effective, then what happens if we put on 2 masks?
Quick answer:
This means the 10% which gets through the 1st mask, will be reduced yet again by 90%. And so we get effectively 99% filtration effectiveness.
Because of the speed and sheer volume of her posts, many people might have missed this. So here, let us capture the full post!
Vaccines and masks
These are 2 effective layers of protection for ourselves and for those around us.
But remember neither are foolproof.
No vaccines are 100% protective, not the best of them, and certainly not the less effective ones.
The best of vaccines are 90-95% effective against symptomatic infection.
This means 1 in 10 can be infected, and at best 1 in 20 will be infected, if they are exposed to a covid carrier.
And don’t forget that a covid cases is most infectious at least a couple of days BEFORE symptoms show up.
So a vaccinated person can be infected, and can be infectious, including being infectious without symptoms showing.
So don’t go yaya papaya just because we have been fully vaccinated.
Wear a mask to protect ourselves and protect others.
And yah, any mask is better than no mask.
Yup! A 3-layer mask with a proper filter may be, just may be, better than a 2 layer mask.
Remember that some 3-layer masks are lousy, with less than 50% filtration efficacy, while decent 2-layer cotton masks could provide as much as 80% protection.
And one of the most important use of a cotton mask is to keep most of our saliva droplets to ourselves, instead of spraying these globules generously around.
And if we are not sure, we can put on 2 masks.
2 masks? Really?
One on top the other?
Suppose we have a mask that is 90% effective, then what happens if we put on 2 masks?
This means the 10% which gets through the 1st mask, will be reduced yet again by 90%.
And so we get effectively 99% filtration effectiveness.
This assumes of course, that the masks are properly sealed around our nose and mouth.
And if we happen to have only 50% effective masks, doubling up will give us 75% effectiveness.
And if we have 70% effective masks, then doubling up will give us 91% effective filtration.
So don’t be shy if you wish to put on a double mask for added protection.
Two masks are definitely better than 1 mask. Yup!
We can also put a surgical mask over our cotton mask, or put on pur cotton mask over our surgical mask, when we go out into public spaces, depending on how we want to manage our masks.
When we are short of masks, we can sterilise and reuse the single use masks. Example: we can sterilise in a UVC box, or hang in tve sun for a few days.
Sure, we can also put on N95 masks if we wish, but that is not really necessary unless we happen to be looking after covid patients, or are working in high exposure risks jobs like swabbing lots of folks.
And no, don’t go yelling at people whose masks have slipped.
Unless they happen to sneeze, the main danger are the saliva droplets big and small from speaking, shouting, singing, coughing, laughing, and praying aloud.
So the more important part for protecting others is to mask up our mouth.
So don’t pull down our mask and go close up to speak to another person in a show of friendliness.
Covering up our nose is more to protect ourselves from others.
Net net, don’t yaya papaya even if we are fully vaccinated.
Continue wearing a mask for added protection for ourselves, and more importantly for those around us.
Keep well!
– Ho Ching
(Featured image via)