Nasal spray could prevent Covid 19

A nasal spray that blocks the absorption of the coronavirus completely protected ferrets it was tested on, according to a small study released Thursday by an international team of scientists. The study, which was limited to animals and has not yet been peer-reviewed, was assessed by several health experts at the request of The New York Times.

If the spray, which the scientists described as nontoxic and stable, is proved to work in humans, it could provide a new way to fight the pandemic, with a daily spritz up the nose acting like a vaccine.

“Having something new that works against the coronavirus is exciting,” said Dr. Arturo Casadevall, the chairman of immunology at the Johns Hopkins Bloomberg School of Public Health, who was not involved in the study. “I could imagine this being part of the arsenal.”

The work has been underway for months by scientists from Columbia University Medical Center in New York, Erasmus Medical Center in the Netherlands, Cornell University and the University of Campania in Italy. The study was funded by the National Institutes of Health and the Columbia University Medical Center.

The spray, which attacks the virus directly, contains a lipopeptide, a cholesterol particle linked to a chain of amino acids, the building blocks of proteins. This particular lipopeptide exactly matches a stretch of amino acids in the spike protein of the virus, which the pathogen uses to attach to a human airway or lung cell.

Before a virus can inject its RNA into a cell, the spike must effectively unzip, exposing two chains of amino acids, in order to fuse to the cell wall. As the spike zips back up to complete the process, the lipopeptide in the spray inserts itself, latching on to one of the spike’s amino acid chains and preventing the virus from attaching.

“It is like you are zipping a zipper but you put another zipper inside, so the two sides cannot meet,” said Matteo Porotto, a microbiologist at Columbia University and one of the paper’s authors.

The work was described in a paper posted to the preprint server bioRxiv Thursday morning, and has been submitted to the journal Science for peer review.

Ferrets are used by scientists studying flu, SARS and other respiratory diseases because they can catch viruses through the nose much as humans do, although they also infect each other by contact with feces or by scratching and biting.

The protective spray attaches to cells in the nose and lungs and lasts about 24 hours, Dr. Anne Moscona, a pediatrician and microbiologist at Columbia and co-author of the study.

“If it works this well in humans,” she said, “you could sleep in a bed with someone infected or be with your infected kids and still be safe.”