Background
Iota-Carrageenan (I-C) is a sulfate polysaccharide synthesized by red algae, with demonstrated antiviral activity and clinical efficacy as nasal spray in the treatment of common cold. In vitro, I-C inhibits SARS-CoV-2 infection in cell culture.
Methods
This is a pragmatic multicenter, randomized, double-blind, placebo-controlled trial assessing the use of a nasal spray containing I-C in the prophylaxis of COVID-19 in hospital personnel dedicated to care of COVID-19 patients.
Clinically healthy physicians, nurses, kinesiologists and others medical providers were assigned in a 1:1 ratio to receive four daily doses of I-C spray or placebo for 21 days.
The primary end point was clinical COVID-19, as confirmed by reverse-transcriptase-polymerase-chain-reaction testing, over a period of 21 days. The trial is registered at ClinicalTrials.gov (NCT04521322).
Findings
A total of 394 individuals were randomly assigned to receive I-C or placebo. Both treatment groups had similar baseline characteristics.
The incidence of COVID-19 was significantly lower in the I-C group compared to placebo (1.0% vs 5.0%) (Odds Ratio 0.19 (95% confidence interval 0.05 to 0.77; p= 0.03). Workday loss in placebo group compared to I-C were 1.6% days / person (95% CI, 1.0 to 2.2); p <0.0001
There were no differences in the incidence of adverse events across the two groups (17.3% in the I-C group and 15.2% in the placebo group, p= 0.5).
Interpretation
I-C showed significant efficacy in preventing SARS-CoV-2 infection in hospital personnel dedicated to care patients with COVID-19 disease.
Low-dose capsaicin (0.01 mM) nasal spray is equally effective as the current standard treatment for idiopathic rhinitis: A randomized, double-blind, placebo-controlled trial
