Nasal spray developed to protect against SARS-Cov-2
A nasal spray that can provide effective protection against the SARS-Cov-2 virus has been developed by researchers at the University of Birmingham’s Healthcare Technologies Institute, using materials already cleared for use in humans.
The spray is composed of two polysaccharide polymers. The first, an antiviral agent called carrageenan, is commonly used in foods as a thickening agent, while the second, a solution called gellan, was selected for its ability to stick to cells inside the nose. The gellan is an important component because it has the ability to be sprayed into fine droplets inside the nasal cavity, where it can cover the surface evenly, and stay at the delivery site, rather than sliding downwards and out of the nose.
The spray works in two primary ways. Firstly, it catches and coats the virus inside the nose, from where it can be eliminated via the usual routes — either nose-blowing or swallowing. Secondly, because the virus is encapsulated in the spray’s viscous coating, it is prevented from being taken up by the body. That means it will reduce the viral load in the body, but even if virus particles are passed on to another person via a sneeze or cough, that person is less likely to be infected by active virus particles.
“Although our noses filter thousands of litres of air each day, there is not much protection from infection, and most airborne viruses are transmitted via the nasal passage,” said study co-author Professor Liam Grover. “The spray we have formulated delivers that protection but can also prevent the virus being passed from person to person.”
In cell culture experiments designed to test the ability of the solution to inhibit infection, the researchers found cell-virus cultures inhibited the infection up to 48 hours after being treated with the solution and when diluted many times. Regular application of the spray could therefore significantly reduce disease transmission, particularly in areas where crowding is unavoidable — such as aeroplanes or classrooms.
“Products like these don’t replace existing measures such as mask wearing and handwashing, which will continue to be vital to preventing the spread of the virus,” added lead author Dr Richard Moakes. “What this spray will do, however, is add a second layer of protection to prevent and slow virus transmission.”
The researchers formulated the spray using compounds already approved by regulatory bodies in the UK, Europe and the US, which are already widely used in medical devices, medicines and food products. This means that the normal complex procedures to take a new product to market are greatly simplified, so the spray could be commercially available very quickly.
“This spray is made from readily available products that are already being used in food products and medicines and we purposely built these conditions into our design process,” Dr Moakes said. “It means that, with the right partners, we could start mass production within weeks.”
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