Efficacy of a nasal spray containing Iota-carrageenan in the costexposure crophylaxis of COVID-19 in hospital personnel dedicated to patients care with COVID-19 disease

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. Research Question: Can a nasal spray with Iota-Carrageenan be useful in the prophylaxis of COVID-19 in health care workers managing patients with COVID-19 disease? Study Design and Methods: This is a pilot pragmatic multicenter, randomized, double-blind, placebo-controlled study 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 other health care providers managing patients hospitalized for COVID-19 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). Results: 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 differs significantly between subjects receiving the nasal spray with I-C (2 of 196 [1.0%]) and those receiving placebo (10 of 198 [5.0%]). Relative risk reduction: 79.8% (95% CI 5.3 to 95.4; p=0.03). Absolute risk reduction: 4% (95% CI 0.6 to 7.4). Interpretation: In this pilot study a nasal spray with I-C showed significant efficacy in preventing COVID-19 in health care workers managing patients with COVID-19 disease. Clinical Trials Registration: NCT04521322.Fil: Figueroa, Juan Manuel. Instituto de Ciencia y Tecnología Dr. César Milstein; ArgentinaFil: Lombardo, Mónica Edith. Nobeltri S.r.l; Argentina. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Dogliotti, Ariel. Instituto Cardiovascular de Rosario; ArgentinaFil: Flynn, Luis Pedro. Sanatorio de Niños de Rosario; ArgentinaFil: Giugliano, Robert. Harvard Medical School; Estados UnidosFil: Simonelli, Guido. McGill University. Montreal Neurological Institute and Hospital; CanadáFil: Valentini, Ricardo. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Ramos, Agñel. Sanatorio Parque de Rosario; ArgentinaFil: Romano, Pablo. Clínica y Maternidad Santa Isabel; ArgentinaFil: Marcote, Marcelo. Gobierno de la Provincia de Buenos Aires. Hospital Interzonal General de Agudos Presidente Peron; ArgentinaFil: Michelini, Alicia. Hospital Pediátrico Avelino Castelán; ArgentinaFil: Salvado, Alejandro. Hospital Británico de Buenos Aires; ArgentinaFil: Sykora, Emilio. Clínica Privada Monte Grande; ArgentinaFil: Kniz, Cecilia. Gobierno de la Provincia de Chaco. Hospital 4 de Junio Ramón Carrillo; ArgentinaFil: Kobelinsky, Marcelo. Clínica Modelo de Morón; ArgentinaFil: Salzberg, David Manuel. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Jerusalinsky, Diana Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Uchitel, Osvaldo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin