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A randomized, controlled, double-blind, proof-of-concept study to evaluate the efficacy and safety of BioBlock® Nasal Spray in the prevention of COVID-19 infection in healthy volunteers

A clinical trial was conducted with the BioBlock®nasal spray containing antibodies against SARS-CoV-2, which was created as a result of collaboration between Estonian scientists and manufacturers, to evaluate its effectiveness in preventing SARS-CoV-2 virus infection and its safety among healthy volunteers aged 18-70.

852 people participated in the study conducted by the University of Tartu, of whom 816 completed the study. The interim results protocol of the study shows that there were almost twice as many infections in the Placebo group as in the BioBlock® group (5 infections in the BioBlock® group out of 406 subjects vs. 9 infections in the Placebo group out of 410 subjects). Based on the interim results of the study, the protective effect of the BioBlock® nasal spray in preventing SARS-CoV-2 virus infection could be concluded.

The analysis of the interim report of the clinical research center of the University of Tartu shows that the BioBlock® preparation was well tolerated by the subjects. The frequency of adverse events was similar between those receiving BioBlock® and those receiving placebo, and there were no serious adverse events in either study group.

In order to increase the statistical value of the results of the study, it would be necessary to increase the number of subjects, assuming that the number of people infected with the coronavirus also increases. To continue with the study until the end of July 2025, there is approval from the Human Research Ethics Committee of the University of Tartu (no. 381/M-8).

The results of the interim report have been submitted to the US FDA and are under review by the Protocol Registration and Results System (PRS). Detailed results will become available on the US FDA’s clinical trial registration website following PRS review.

The study was organized by Chemi-Pharm AS, as sponsor, in cooperation with the Institute of Public Health and Family Medicine, Institute of Clinical Medicine and Clinical Research Center of the University of Tartu, Meliva Qvalitas AS and Icosagen Cell Factory OÜ.

Antibodies with proven effectiveness

A series of profound in vitro testings of antibodies in BioBlock® nasal spray have already been conducted prior performing the above-described clinical study, and the results were published in a scientific article [1]. Experiments have proven the efficacy of antibodies on the original and currently circulating mutated virus strains (including omicron B.1.1.529 and its sub forms XBB 1.5, BA.1, BA.2, BA.4, BA.5, BA.2.75.2, BA .2.3.20, BQ.1.1). BioBlock® Nasal Spray and the antibodies content of it are developed and tested regularly following the global situation COVID-19 disease and the mutation of the virus strains.

Conclusions and recommendations

The escalation of the flu season is also likely to increase the number of people infected with the coronavirus.

The results of all conducted studies show that BioBlock® is an important and safe additional protection measure against SARS-CoV-2 viral infection. We recommend using it in situations with difficulties in social distancing, such as at home, at work, at school, at training, in public transport, and social events.

Published scientific article in PLOS ONE scientific journal about immunized antibodies content of BioBlock® nasal spray and their effectiveness against SARS-CoV-2 viral infection, 2022: