Upper respiratory tract infections
SARS, influenza, RSV, common cold, …
2020-11-24 — 2025-11-01
Wherein the modes of respiratory contagion are surveyed, topical remedies are described, and a nitric‑oxide nasal spray, Enovid/VirX, is noted as having passed clinical trials.
1 Epidemiology of
See also epidemiology, contact tracing.
2 Topical sprays
Various nasal sprays are used for colds and other viruses; some might affect COVID-19 or other respiratory viruses (Fais et al. 2022; Friedland et al. 2022; Kozlov 2022; Little et al. 2024).
2.1 Iota-carrageenan
Seems legit (Figueroa et al. 2021; Hemilä and Chalker 2021). Available in Australia as Flo travel.
2.2 Nitric oxide nasal sprays
Topical nitric oxide (Salman 2021) passed clinical trials (Sanotize Research and Development corp. 2021; Winchester et al. 2021) and has been released as a product, Enovid/VirX, in a slow-release nasal spray formulation.
enovid and VirX are the identical product, branded under different names for marketing in various territories around the world. Nitric Oxide Nasal Spray (NONS) is the generic name of the product.
2.3 Hypochlorous acid nasal sprays
Very recent. Seems credible and also happens to be approved in many jurisdictions (Winter, Boecker, and Posch 2025).
2.4 Povidone-iodine (PVP‑I)
Seems credible. No companies have bothered to apply for TGA approval in Australia yet, AFAICT.
2.5 Zinc
No longer supported (Hemilä and Chalker 2024; Hulisz 2004; Hunter et al. 2021; Ronald 2001) since it has weak effects at best and some risks of anosmia (losing your sense of smell) (Jafek2004Nasal?; Mavragani2021Loss?).
3 Airborne transmission
There are probably several reasons that we were slow to be careful about sharing the contents of our lungs with each other int he west. Here’s an interesting one: The 60-Year-Old Scientific Screwup That Helped Covid Kill documents the debate about which particle sizes can transmit viruses, and traces the lineage of cargo-cult science that helped those misunderstandings persist.
3.1 protective masks
See hygienic masks for details on mask types and fit.
4 COVID-19
All my COVID-19 content is archived here.
5 Incoming
Andrew Snyder-Beattie on the low-tech plan to patch humanity’s greatest weakness
Andrew Snyder-Beattie, head of Open Philanthropy’s biosecurity programme, puts the risk of human extinction from a biological catastrophe at 1–3% in our lifetimes.
However, he argues that a concrete, largely low-tech “four pillars” strategy could dramatically reduce this risk by buying us the time needed to survive even the worst-case scenarios.