Efficacy of a nasal spray containing Iota-Carrageenan in the prophylaxis of COVID-19 in hospital personnel dedicated to patients care with COVID-19 disease A pragmatic multicenter, randomized, double-blind, placebo-controlled trial (CARR-COV-02)
Authors: Figueroa Juan M. , Lombardo Mónica , Dogliotti Ariel , Flynn Luis P. , Giugliano Robert P. , Simonelli Guido , Valentini Ricardo , Ramos Agñel , Romano Pablo , Marcote Marcelo , Michelini Alicia , Salvado Alejandro , Sykora Emilio , Kniz Cecilia , Kobelinsky Marcelo , Salzberg David , Jerusalinsky Diana , Uchitel Osvaldo ,   CARR-COV2 Group Trial
Published: April 2021

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 COVID19 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-Cc 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.

Research in context

Evidence before this study

We searched PubMed for research articles published up to February 14, 2021, with no language restrictions, using the terms “SARS-CoV-2” or “COVID-19”, “prevention”, “clinical trial”, and “prophylaxis”. Except for studies on vaccines we only found three peer-reviewed publications available on the efficacy of Hydroxycholoquine to prevent COVID-19 disease in individuals at risk of exposure. Hydroxychloroquine did not prevent COVID-19 used as pre or postexposure prophylaxis. We also did not find results from clinical trials on the efficacy of carrageenan in the prevention or treatment of cOVID-19.

Added value of this study

We report the clinical efficacy of a nasal spray with Iota-Carrageenan for the prevention of COVID-19 disease in a randomised, double-blind, placebo-controlled, multicentre study in República Argentina, including 394 participants.

Implications of all the available evidence

A simple intervention such as the administration of a nasal spray with Iota-Carrageenan, in addition to hand hygiene, use of personal protective equipment and social distancing, could provide additional protection until vaccines can be administered to the majority of the population.