https://www.pnas.org/doi/10.1073/pnas.2319566121
In case you're wondering, this paper is 100% legit, see e.g. the bio for the big-shot author: https://en.wikipedia.org/wiki/Akiko_Iwasaki
No clue if this easy trick would induce immune escape if a large number of people started using it. I guess it's a good time to get in on the ground floor.
1. "Prophylactic or therapeutic administration of neomycin provided significant protection against upper respiratory infection and lethal disease in a mouse model of COVID-19." 2. "Furthermore, neomycin treatment protected Mx1 congenic mice from upper and lower respiratory infections with a highly virulent strain of influenza A virus. " 3. "In Syrian hamsters, neomycin treatment potently mitigated contact transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)." 4. "In healthy humans, intranasal application of neomycin-containing Neosporin ointment was well tolerated and effective at inducing ISG expression in the nose in a subset of participants."
The mechanism appears to be that Neosporin triggers an ISG[1] (immune) response? Not a biologist etc, but the results showing that it prevents transmission is only in rodent models, and then showing that a similar biomarker shows up in (some of) the participants and the rodent models. They authors say:
> "These findings suggest that neomycin has the potential to be harnessed as a host-directed antiviral strategy for the prevention and treatment of respiratory viral infections."
[1]
https://classic.clinicaltrials.gov/ct2/show/NCT05449392
Here's Eric Topol's chat with Iwasaki discussing the finding. Topol's blog may well be the best source for Covid research out there:
https://erictopol.substack.com/p/akiko-iwasaki-the-immunolog...
Obviously it’s not stimulating the immune system but it works as an antiviral barrier. I’ve been using it since I read that study and I’ve avoid 2 of my daughter’s colds since (and still got 3). That might not sound impressive but I have a terrible immune system and haven’t avoided a cold from someone I’ve had close exposure to in as long as I can remember.
That said, I might need to add some Neosporin to my mixture when she comes home with her nose running.
For 150ml of (distilled) water: 1.35g of salt 1.8g of iota carrageenan A drop of polysorbate 20
Heat up the water to close to boiling, add those things, shake it up, and there you go.
Note: That was supposed to be in line with the product that was tested, but I've found adding more water makes it come out of the nose spray bottle thing better. It's still pretty thick, just not a complete gel. Perhaps there's another type of spray bottle that would be better.
Essentially, yes, neomycin in the nose, if timed perfectly, can activate the innate immune system, but en mass this practice would cause the spread of antibiotic resistance.
Link: https://podcasts.apple.com/us/podcast/this-week-in-virology/...
Besides, we're already spiraling down the resistance chasm with antibacterial soaps, stuffing cattle with antibiotics, overprescribing, and so on.