University of Edinburgh researchers hope to build on a pilot study that suggested gargling a saline solution, along with “nasal irrigation”, reduced the duration of illness in people who had a common cold.
Viral shedding and, therefore, transmission, were reduced in people who employed the salt wash, that initial trial found, though not at statistically significant levels. It gathered full results from 54 people, most of whom were infected with rhinovirus but some of whom had coronaviruses.
Experts said certain human cells were able to use chloride ions (a component of sea salt) to synthesise hypochlorous acid, which is the active ingredient in bleach and is known to have antiviral properties. The planned treatment would supply those cells with additional chloride ions.
On their recruitment website, they said: “As Covid-19 is a new strain of coronavirus we do not know if nasal washout and gargling salty water will have the same effect as previously seen in other strains.
“If you take part in this trial and are asked to carry out the nasal washout and gargling you may or may not get a direct benefit, your symptoms may or may not get better quicker and other people in your household may or may not be protected from being infected.
“These are the questions we are going to investigate through this study.”
Professor Aziz Sheikh, director of the University of Edinburgh’s Usher Institute, added of the gargling process: “It only requires salt, water and some understanding of procedure so should – if found to be effective – be easy and inexpensive to implement widely.”
People taking part in the new trial will be asked to follow government advice on hygiene and self-isolation. One group will be asked to gargle and clear their nose with salt water and another will not.