Consultations with dermatologist Dr Shawana Vali involve a face-to-face approach that might seem to put both her and her patient at risk of Covid-19.
‘I’ll almost always start with an examination of the patient’s face and skin, which means standing very close to someone who is unmasked for half an hour or more,’ says Dr Vali, co-founder of the LMS Wellness in Chelsea.
It’s now known that the virus behind Covid-19 is almost entirely airborne.
Normal breathing alone can produce thousands of virus-laden aerosols — the volumes are even larger if you shout, cough or sneeze.
Consultations with dermatologist Dr Shawana Vali involve a face-to-face approach that might seem to put both her and her patient at risk of Covid-19
And if let undisturbed — for instance, in an unventilated space — aerosols can ‘float in the air’ for up to ten hours, says Valerie Edwards-Jones, a microbiologist and an emeritus professor at the School of Healthcare Science at Manchester Metropolitan University.
Yet the team at LMS Wellness has remained at work — lockdowns permitting — with no more protection than the average person wears to a supermarket.
Except for one thing — the face masks they use, set to be the next big thing in personal protection, are coated with a virucidal (virus-killing) agent, titanium dioxide, which has been shown by laboratory tests at the University of Cambridge to ‘effectively inhibit infection by Covid-19 for up to 120 days’.
This is according to tests carried out by virologist, Ravi Gupta, a professor of clinical microbiology at the university.
Professor Gupta was named in the TIME 100 most influential people last year for his work on a cure for HIV using a bone marrow transplant from an HIV-resistant donor.
In December 2020, he hit the headlines again when he led the team that identified the highly infectious new strain of Covid that emerged in Kent.
In an exclusive interview with Good Health, Professor Gupta says: ‘With the new variant of SARS-CoV-2, we need more than ever innovative protection. Most important is deactivation of the virus on a mask so that it cannot be transmitted by touch.’
Anti-viral protection has traditionally worked on the assumption that infections such as flu are spread by large, even visible droplets that shoot through the air on coughs and sneezes, landing on surfaces — so wiping surfaces and washing hands have been vital.
But however flimsy they are, masks have become key, shown to reduce the spread of viruses by blocking the spread of respiratory droplets. A study of simulated coughing, for instance, found that even a stitched cloth mask reduced the ‘jet distance’ in all directions from 8 ft to 2.5 in.
For most masks to be effective, they need to be worn by everyone — and in the case of cloth masks, made of three layers, according to the latest advice from the World Health Organisation.
Single-use masks include the popular, three-layer surgical version, which has a middle layer with a very fine weave said to block 85 per cent of particles. They are cheap (under £20 for a pack of 50) but, like cloth masks, they don’t protect the wearer.
More effective are N95 masks (also known as KN94, FFP2 or ‘respirators’, these cost around £20 for ten). They filter 95 per cent of large and small airborne particles and are widely used in hospitals.
Providing even greater protection, and also widely used in hospitals, are FFP3 ‘fine dust’ masks (costing around £70 for six). They block a minimum of 99 per cent of very fine particles such as asbestos and Covid-bearing aerosols.
A downside, however, is the comfort factor. N95 masks need to be tight-fitting to be effective. And even FFP3 masks, which come in different types, sizes and models, don’t necessarily fit everyone.
Single-use masks include the popular, three-layer surgical version, which has a middle layer with a very fine weave said to block 85 per cent of particles. They are cheap (under £20 for a pack of 50) but, like cloth masks, they don’t protect the wearer
An unpublished survey by Addenbrooke’s Hospital and the University of Cambridge, and supported by the Royal College of Surgeons, found that one in four doctors feels unsafe with the protective masks currently provided.
‘We also found that doctors with smaller or flatter faces are more at risk of being infected with the virus even though they are wearing FFP3 masks,’ Dr Ambika Chadha, a maxillofacial surgery trainee at Addenbrooke’s, told Good Health.
Further, single-use masks present a major pollution problem on disposal. And masks can also spread disease if not placed in special bins and handled appropriately, according to Professor László Forró, a researcher at the Laboratory of Physics of Complex Matter at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland.
The latest innovations are masks that don’t simply act as a barrier, but destroy pathogens.
Some reusable masks are ‘anti-microbial’, consisting of two or three layers with an inner-layer infused with a coating made from silver or copper — this is said to attack viruses and bacteria that land on the mask. (A company set up by Professor Edwards-Jones now sells three-layer masks with a silver impregnated lining at a cost of three for £20.)
But perhaps an even more promising breakthrough, say experts, centres on titanium dioxide (Ti02).
Ti02 has proven virucidal properties and is a widely used chemical — for instance, in dental implants.
In August, a study from EPFL in Switzerland confirmed that masks with the coating can ‘kill germs and be reused up to 1,000 times’.
Now a London-based company has launched one of the first products with this molecular technology to reach the market: the Invisi Smart mask.
‘What’s new,’ explains Jeremy Ramsden, an honorary professor of nanotechnology at the University of Buckingham, ‘is not the basic material, titanium dioxide. That’s been used for years in industry.
‘The real innovation is getting it to stick without inactivating it.’
The Invisi Smart mask looks and feels like an ordinary surgical mask. But laboratory tests by Professor Gupta at the Cambridge Institute for Therapeutic Immunology and Infectious Diseases, a department within the University of Cambridge, suggest it is hardly ordinary.
The tests, which were funded by Invisi Smart Technology (the only financial link that Professor Gupta has with the company), came out in November on the Covid-19 preprint server, bioRxiv, a website scientists use to quickly share developments before they’ve been peer-reviewed. So far, the tests have involved SmartShield, the manufacturer’s Ti02-infused coating for surfaces which was applied by a spray gun to surfaces in volunteer clinics (it is claimed the protection will last up to five years on surfaces.)
The as-yet unpublished laboratory tests also showed it destroyed an artificial version of the virus that causes Covid-19, says Professor Gupta.
With the four-ply reusable face mask, the Ti02 is contained in an inner layer — the mask can be washed to remove surface dirt, with the protection lasting at least 30 days (each mask costs £7.19. There is another version which lasts five days, costing £4.75 each). One problem is that to make them cost-effective, the virucidal masks need to be re-used for a significant period of time.
‘That will require a culture change as doctors and nurses are so used to one-use only masks,’ says Dr Chadha, who wears a Invisi Smart mask outside the hospital but not so far during clinical duties as it’s not been approved for NHS use.
Dr Alkesh Patel, a dentist at Maison Smile in Edgware Road in London, whose practice took part in the trial, adds: ‘Staff members are still automatically throwing their “Invisi” mask away each day.’
When wearing two masks may be better than one
Could wearing two masks instead of one be the best way to protect yourself?
The idea of double-masking is based on the theory that building up multiple layers of filters will further reduce the chance of tiny coronavirus particles infecting you or others. It might also compensate for any inadequacies of the other mask, such as looseness.
Numerous studies have now shown that face masks can reduce the transmission of Covid.
In the journal Proceedings of the National Academy of Sciences in December, researchers found that in the 20 days after masks became mandatory in Germany, the number of new infections fell by 45 per cent. Now a U.S. report in the journal Med suggests that one option for maximum protection is wearing two masks.
The researchers reviewed existing evidence on different types of face coverings. For basic protection, they recommended a ‘high-quality surgical mask or a fabric mask of at least two layers with a high thread count’.
But another option was double masking — wearing a cloth mask ‘tightly on top of a surgical mask’, they said; the surgical mask acts as a filter and the cloth mask provides an additional layer of filtration while improving the fit.
An effective alternative is a single, ‘three-layer mask’ (with the outer layers consisting of a flexible, tightly woven fabric that moulds to the face, and the middle layer a high-efficiency filter, such as vacuum bag material).
Both options, if well fitting, should prevent more than 90 per cent of aerosols from getting through, concluded the review by the University of California. (By comparison, a study in the journal mSphere in October found a cotton mask is 20 to 40 per cent effective; the gold-standard N95 mask prevented 80 to 90 per cent of virus particles).
While in theory double-masking makes sense, a better option is simply a properly fitting mask, says Dr Andrew Preston, a reader in microbial pathogenesis at the University of Bath.
‘A face mask should have more than one layer to provide the filtration required without making breathing too uncomfortable,’ he says.
‘Fit is important: poorly fitting masks will expel our breath through gaps.’
Tweaks to enhance a mask’s fit include ties that secure the fabric around the back of the head — relying on ear loops allows masks to hang and gape — and choosing one with a nose bridge. ‘Rather than hoping two poor masks will work, focus on using a multi-layered single mask that fits properly,’ says Dr Preston.
Source: Daily Mail |World News