Carrageenan nasal spray may double the rate of recovery from coronavirus and influenza virus infections: re-analysis of randomized trial data

Abstract

Carrageenan is a sulfated polysaccharide that has been extensively used in food products. Since the 1980s, carrageenan has been shown to prevent infections due to several viruses in cell cultures, including rhinoviruses which cause the common cold. In animal studies it prevented mortality caused by influenza A. Carrageenan is generally regarded as safe by the FDA. This individual patient data meta-analysis examined the datasets of two randomized placebo-controlled trials which investigated the effect of carrageenan separately on children and adults. In both trials, iota-carrageenan was administered nasally 3 times per day for 7 days for patients with the common cold and follow-up lasted for 21 days. Nasal carrageenan increased the recovery rate from all colds by 54% (95% CI 15% to 105%; P = 0.003). The increase in recovery rate was 140% in coronavirus infections, 119% in influenza A infections, and 70% in rhinovirus infections. We used quantile regression to calculate the effect of carrageenan on colds of differing lengths, by dividing the distribution into 5 quintiles. The mean duration of colds in the placebo groups of the first four quintiles were 4.0, 6.8, 8.8 and 13.7 days, respectively. The fifth quintile contained patients with censored data. The 13.7-day colds were shortened by 3.8 days (28% reduction), and 8.8-day colds by 1.3 days (15% reduction). Carrageenan had no meaningful effect on shorter colds. In the placebo group, 21 patients had colds that lasted over 20 days, compared with 6 patients in the carrageenan group. This corresponds to a 71% (P = 0.003) reduction in the risk of longer colds. Finally, in the placebo group, 37 patients had recurring cold symptoms after first being cured, compared with 16 in the carrageenan group. This corresponds to a 56% (P = 0.002) reduction in the risk of recurring symptoms. Given that carrageenan has an effect on diverse virus groups, and its demonstrated effects on two old coronaviruses, it seems plausible that nasal carrageenan may also have an effect on the new coronavirus SARS-CoV-2. Further research on nasal iota-carrageenan is warranted.

The Saliva of Probands Sucking an Iota-Carrageenan Containing Lozenge Inhibits Viral Binding and Replication of the Most Predominant Common Cold Viruses and SARS-CoV-2

“…5 Hemilä et al performed an independent meta-analysis with publicly available data from clinical studies with an iota-carrageenan containing nasal spray. 21 The authors attest the quality of the available clinical data as well as the broad effectiveness against influenza viruses and endemic coronaviruses. They further conclude that nasal Notes: The respective viruses were incubated with a dilution series of the treated saliva samples before infection of a susceptible cell line.…”

Carrageenan nasal spray may double the rate of recovery from coronavirus and influenza virus infections: Re‐analysis of randomized trial data

“…We thank Dr. Eva Prieschl‐Grassauer for additional information about the methods used in the two included trials, 25,27 and for confirming that our extracted data for all‐virus positive colds and for influenza A virus colds were correct, and for giving us the data for the rhinovirus and coronavirus colds. An earlier version of this manuscript was published on a preprint server 55 …”

Exploring the therapeutic potential of marine-derived bioactive compounds against COVID-19

“…An iota-carrageenan-based nasal spray was also developed, which was found to be efficacious in patients with a common cold, one of the common symptoms of human coronavirus 229E (alpha) and human Covid OC43 (beta). Its administration has shown a decrease of 2.5-fold in reoccurring symptoms and enhanced viral eviction in comparison to the patients treated under placebo control (Hemilia and Chalker 2020;Koenighofer et al 2014). Graf et al, in 2018, developed a nasal spray involving xylometazoline hydrochloride (0.05%) and carrageenan (0.12%).…”