Will dabbing Neosporin up your nose help prevent Covid?

Could this antibiotic ointment even be used to help treat Covid, influenza, and other viral infections?

It sounds like a nonstarter.

Use an antibiotic ointment formulated to kill bacteria to help stop viruses instead.

And yet neomycin, one of the antibiotic ingredients in Neosporin, has been shown to help prevent and even treat infections with SARS CoV-2 in mice. How is that possible? It really is quite mind-blowing. I’m going to review the recent study that came out a few months ago in Proceedings of the National Academy of Science journal. To say that it has been overlooked is an understatement in my opinion. I think there is a lot of promise here, as Neosporin is cheap, readily available, and has few side effects when administered topically/intranasally. The study was carried out by Yale researchers headed by Dr. Akiko Iwasaki, with support from the Bill & Melinda Gates Foundation.

But before I get into this, I want to qualify the post you are about to read. The bulk of the study was performed in mice and hamsters, but showed benefits for both preventing and treating infection with SARS-CoV-2 and influenza A viruses in those animals. The study stopped short of following through with a randomized clinical trial in human beings to assess efficacy in preventing/treating infections, but did find the same mechanism of action being turned on in human noses administered neomycin - the induction of antiviral interferon genes.

Interferon (IFN) is a natural protein produced by white blood cells and other cells in the body's immune system to help fight infections, cancer, and autoimmune diseases. Interferons are signaling molecules called cytokines that "interfere" with viruses and other germs to prevent them from multiplying. They also play a role in tumor suppression, activating immune cells, and signal transduction.​​​​​​​​

Sometimes a picture can tell a story. Here’s a pathology slide that I found compelling. You can see the difference between the nasal mucosa of mice treated with placebo ointment (vehicle) and the actual 2 mg of neomycin. The stain shows SARS CoV-2 viral proteins in the surface layer of the nose.

Which one looks better to you, vehicle or treatment group?