Wearing sunglasses or spectacles can provide some protection from the spread of Omicron according to Professor Mary-Louise McLaws, a Professor Epidemiology of Hospital Infection and Infectious Diseases Control at the University of New South Wales.
In an interview with Australian Science Media Centre, Prof McLaws, who is also a member of the World Health Organization (WHO) Health Emergencies Program Experts Advisory Panel for Infection Prevention and Control Preparedness, Readiness and Response to COVID-19, spoke about the role of masks and eyewear.
With Omicron, one of the things I think we should be doing is telling people to look after their eyes – I ask them to wear glasses, sunglasses or anything to protect their eyes because their eyes have what’s called ACE2 receptor sites
Q. How well do cloth masks work at preventing the spread of COVID-19?
“As a WHO member of the Infection Prevention and Control group for COVID-19, the cloth masks have to have three layers. The cloth masks have to follow the WHO cloth agreement and if they don’t, they won’t protect the wearer. Following those guidelines with a cloth mask prevents people from breathing out or in the virus through the three materials.”
Q. How can the public know if their cloth mask is up to standard?
“If they’re buying the cloth mask from a provider, people need evidence that the cloth mask is made according to the WHO video procedure that tells people how to make a cloth mask with three layers.
People could possibly check the cloth mask actually has two outer layers by using their fingers to see if there’s an independent inner layer, and an outer layer. Try to pull each layer apart and that will let them know if there are two outer layers and one inner layer. If they can’t do that, then it should be telling them there’s one single layer, and one single layer is not enough.
Two layers are not enough without a middle third layer to prevent anything that might get through the outer layer. The middle layer is supposed to be a bit like the inner layer of a medical mask that is charged [with static electricity].
If it is a three-layered mask, one of the ways of getting that inner layer to be charged to prevent a particle from coming through that middle layer is to gently rub the mask between your fingers and that should increase the charge of the middle layer.
If there’s just one layer, then that single layer cloth mask can get wet very quickly and once it’s wet then anything can get through very, very easily.”
Q. What are some mistakes people can make with wearing cloth masks?
“Thinking that they’re safe if they wear it under their nose. If they’ve got COVID-19 and they’ve got no symptoms at all, they could be breathing out the virus through their nose. If they’re not infected, then they could be breathing in Omicron or Delta through their nose and it can go to their brain, go to their lungs, so they’re putting themselves at great risk.
They’re probably just wanting to have a breather because they’re finding the masks very uncomfortable and they are, but when you’re indoors, wear your mask over your nose. Then when you’re outdoors, put the mask totally under your chin, and then remember if people are walking towards you put your mask back over your mouth and nose.
When people start putting their mask under their nose, they’re very easily forgetful that they’ve still got an entry and exit area for the virus.
Their cloth masks also need to be cleaned to protect themselves, so they need a couple of triple layered cloth masks they can wash and dry.
With all this terrible humidity in Australia at the moment, if the mask gets wet their mask won’t work, so they need to have a spare one.”
Q. With more contagious variants spreading, should the public consider switching to surgical masks or even P2/N95 masks?
“Medical masks, otherwise called a surgical mask in Australia, work well even though Delta and Omicron live in the air and can develop airborne spread rather than just droplet.
Droplet transmission is when the virus comes out of your mouth and is heavy, more than five microns, like dwelling in saliva for example, so a droplet drops to the floor very, very quickly.
With Omicron, it’s not scientifically tested yet, but there’s a suggestion by some of the physicists in America that Omicron spike has the ability to be charged – negative and positive charges – which then allows that saliva or lung fluid to surround the virus, still lighter weight, but this stops the virus from drying out fast. It’s not heavy, its very light and it can stay in the air indoors for a much longer time so that you can be at risk of airborne spread.
When you’re a healthcare worker, to protect yourself from airborne spread you wear a particular mask called a P2 or N95 and a face shield, but that’s because you’re about to do an aerosol generating procedure – in other words, it causes the viruses to be very tiny when you’re doing procedures like intubating a patient.
In NSW for example the Clinical Excellence Commission is in line with the WHO that requires healthcare workers to wear a surgical/medical mask while treating a patient with COVID-19, because it’s still unlikely they are at risk of aerosol particles that could still get through the mask if wet. Without performing an aerosol generating procedure they are not going to get a faceful of virus, and neither are you in the public, even from aerosol particles living in the air for longer than droplets that drop to the ground faster.
Patients breathe out and then particles will go into the air, stay in the air for longer, but the healthcare worker wears a surgical mask plus eye protection to protect their eyes and their nose and mouth – they are well protected and they don’t need to wear a P2 mask when they perform routine healthcare.
P2 masks are about three times the cost and are very difficult to wear for the whole shift because they’re hard work to breathe through. There’s no evidence that you in the community really need to wear a P2 or N95 mask because you aren’t going to get virus particles forced through a mask.
In the community, it’s unlikely you really do need to wear an N95 plus eye protection, if that’s what you want to wear that’s great, but you’ll likely be fine [with a three layered cloth or surgical mask] both indoors or outdoors even though the virus is airborne.
If people want to wear a P2 or an N95 they can buy them, the ones from Korea aren’t bad, a hospital P2 mask is even better, but they find it hard to wear all day long – for eight hour shifts or even three hours between wearing it and having a break, it’s a very long time.
Good surgical masks are okay, people can also get a better fit if they cross the elastic loop before the elastic goes behind their ear, that brings the mask closer to the side of their face if they have a small face.
For people like myself, it’s better, because you often get those masks and they’re one size fits all and it feels like there’s a gap – to cross the loop over will make the mask fit tighter against their face.”
Q. What else can people do to protect themselves while out in the community?
“With Omicron, one of the things I think we should be doing is telling people to look after their eyes – I ask them to wear glasses, sunglasses or anything to protect their eyes because their eyes have what’s called ACE2 receptor sites [entry points for the virus]. If you’re indoors in a shop and somebody has breathed out through their nose because they’re not wearing their mask over their nose or not wearing a mask over their mouth then it could get into your eyes, so it would be great if people protected their eyes when they were indoors in a shopping mall.”
