The Sanotize phase 2 trial was clever, in that they only looked...

The Sanotize phase 2 trial was clever, in that they only looked at the effect of the spray on viral load in already-confirmed patients with mild Covid. So rather than the n=15,000, 6 month-plus studies required of vaccines to demonstrate efficacy in disease prevention, they could just recruit 80 patients and study for two weeks. Their data was robust enough to show a reduction in viral load over the 6 days of treatment in the Sanotize group versus placebo. But their claim that it also reduces severity of infection is quite dodgy, as it’s based on a self-reported questionnaire over 2 weeks, but one where less than half of the Sanotize group completed the questionnaire (n=15), and only just over half the placebo group did (25).

I would classify the Sanotize data as one level better than Viraleze, in that they’ve got some human data showing effects on viral load in mild symptomatic disease, although there’s still no definite clinical correlate between that and severity of disease, or risk of transmission. So still not convincing enough to be used routinely in clinical practice, but maybe good enough that more people might just buy it anyway, or the NHS foundation trust might be willing to give more money to do larger-scale trials.

But Sanotize, Viraleze or any other nasal spray are likely to be less effective at preventing disease than vaccines, and just used as an adjunct with masks, etc. So it would need an extremely large number of people to be using it daily as a preventative, to get enough people infected in the placebo group to then be able to determine if there’s a difference in the treatment group.

If anything, a more focussed trial in high-risk exposure, like family members of cases, or close contacts in school/childcare outbreaks, would be the best way to go to prove efficacy in disease prevention. But the logistics behind organising such a trial, where rapid identification and recruitment is required, would also be beyond SPL’s capability, and would require high-level collaboration with clinical researchers in major tertiary hospitals and the state health departments (assuming it took place in somewhere like Victoria).