Researchers have discovered a new peptide, delivered in the form of a nasal spray, that has the potential to end the pandemic sooner than later. It appears to block transmission of the SARS-CoV-2 virus in ferrets, and if it proves effective in humans, a squirt or two up the nose would prevent contagion by even large amounts of virus. The only question is how long it will take to find out.
In a small study published yesterday in bioRxiv and currently undergoing peer review, two ferrets were given the nasal spray and another two a placebo. Researchers stuck them in a cage with another ferret that had been infected the day before, and 24 hours later, out they came—two perfectly protected and two infected.
Were the spray to protect humans as well as it does ferrets, it would be comparable with a successful vaccine in terms of its ability to prevent the spread of disease—not to mention better than many of the Covid-19 vaccines currently in phase 3 clinical trials that have proven only moderately effective. Rather than mitigating symptoms after the fact, the nasal spray would work prophylactically to stop infection altogether.
Infection by SARS-C0V-2 involves the fusion of the membranes of the virus and of host cell proteins. In a series of previous studies by the authors of the current study, they showed that the peptides which inhibit the fusion process may inhibit the fusion of the measles virus, human parainfluenza virus type 3, and the Nipah virus. In this study, they show that a similar peptide acts as a potent inhibitor of fusion by SARS-CoV-2, both in cells and in ferrets.
Beyond the novelty and promise of the approach, the study is notable for a number of reasons. First, the researchers took considerable care to mimic the natural process of exposure and infection, cohousing the treated and untreated ferrets with ones that had been infected with SARS-CoV-2. While occasional tussling and biting might provide opportunities for transmission, it was just as likely that the ferrets would contract the virus simply by sharing the same air—much as we humans do.
Second, manufacturing the nasal spray en masse would be relatively straightforward. Large quantities of the peptides that constitute the spray can be made quickly and easily. They can be delivered in a liquid formulation, freeze-dried, then reverted into liquid once more, entirely suitable for spraying into the human nose, according to the researchers. Because of the simplicity of the process and components involved, the spray would also be inexpensive to produce and ideally inexpensive to purchase.
The study, like any other, comes with a few caveats. One is that it remains to be seen whether human mucosa—the mucous membranes that line our nose and other bodily cavities—behave like ferret mucosa. Another has to do with the ability of SARS-CoV-2 to mutate and potentially bypass attempted blockage. Although SARS-CoV-2 isn’t as quick to mutate as other viruses, it is possible that the efficacy of the spray might vary depending on the strain.
Both the public and private sector—pharmaceutical companies, the National Institutes of Health, Operation Warp Speed—should put their full weight behind testing this nasal spray in humans as quickly and forcefully as they are with vaccines. If they do and the spray is found to be safe and effective in humans, it could be brought to market and available for use in as little as six months. This nasal spray may be the breakthrough we’ve been waiting for to end the pandemic. It will require a bold commitment from the federal government, but if anything deserves warp speed, in my opinion it’s this.