Covid-19, can a nasal spray protect against contagion?

Against Covid-19 a nasal spray created was able to stop the virus and prevent it from spreading to ferrets. The result, for now preliminary and on animals, could block the coronavirus in the nose and be used as a preventive tool in addition to other measures

(photo: mohamed Hassan via Pixabay) After the mouthwashes against the new coronavirus today is the turn of a nasal spray that may prove effective in fighting and preventing Sars-Cov-2 from infecting the body in the nose. This spray, which contains a new antiviral, was developed by a group from Columbia University Medical Center in New York, coordinated by Italian researcher Matteo Porotto and Anne Moscona. For now, the authors have only tested the compound on ferrets, although the first results have been very promising. The research, not yet peer reviewed, is available in preprint on bioRxiv.

The data are preliminary and also remember that the contagion from Covid-19 occurs mainly from droplets of saliva (droplets) and residues of these droplets ( aerosol), as well as from contact of infected hands with mucous membranes, not only those of the nose, with processes that cannot be blocked - at least not all - by the preventive use of this nasal spray, even if it will also be confirmed effective in humans . Despite these limitations, the compound created could prove to be an efficient weapon, in addition to other protective tools, against the spread of the coronavirus.

Blocking the spike protein of Sars-Cov-2

Scientists are engaged in the research and development of molecules called lipopeptides, or small proteins linked to a lipid (a fat) such as cholesterol or tocopherol (present in many vegetables, in olive oil and more). These molecules act by preventing a virus from binding to the membrane of the host cell, the cell of the organism that will let the pathogen enter and will be infected. The Sars-Cov-2 coronavirus uses its spike protein to penetrate cells and create a bond.

The new compound recognizes the spike protein, inserts itself and engages in the region where virus contact occurs and cell and prevents the spike from adopting the shape necessary to bond with the cell. The authors had already described the compound in a recent study on mBio, in which the molecule had been tested on humans in a 3D model, therefore with a computer simulation, in which it had been shown to be effective.

The study on the nasal spray

In the experiment, the authors selected ferrets, often studied in clinical research because their respiratory diseases resemble the forms that affect humans. After receiving the nasal spray, six ferrets were put in contact with six infected and coronavirus positive animals. The contact was very close and lasted more than 24 hours. After this time, the researchers found that none of the animals treated with the antiviral had been infected and the presence of Sars-Cov-2 infection was not detected in the swab, in the nose and throat. Conversely, ferrets that did not receive the nasal spray were all infected. The authors explain that it is simple to administer the antiviral nasally and that its action is immediate and lasting, as it covers a period of 24 hours.

Nasal spray: before and immediately after exposure to the virus?

Today, researchers propose the molecule as a nasal antiviral candidate. It being understood that the nasal spray does not cure Covid-19, the hypothesis is that it can be useful as a preventive tool, before any exposure to the virus, or as a prophylaxis immediately after being exposed, therefore after having had contact with a positive person. Given the results that show the compound is safe and valid, the authors now hope to be able to test it on human volunteers as soon as possible