Coronavirus: Nasal vaccines yielded disappointing results

Source: Kathimerini Cyprus

The initial trial of a nasal vaccine against coronavirus developed by the University of Oxford with funding from the pharmaceutical company AstraZeneca resulted in disappointment. The vaccine, which is administered through the nose, raised hopes that it would be more effective in preventing virus transmission.

The nasal vaccine, a modified version of the two collaborators' well-known conventional vaccine, elicited antibodies in "a minority of participants" (no exact percentage was given), but the systemic immune response it elicited was weaker - based on blood biomarkers - than the regular injectable vaccines, according to the University.

Although intramuscular vaccines are very effective against severe disease, they only provide limited protection against infection, whereas a nasal vaccine could theoretically block inhaled virus particles from entering the lungs more directly.

Dr. Sandy Douglas, the lead researcher at the Jenner Institute in Oxford, admitted that the nasal vaccine in trials appeared to fall short of expectations. "We believe that nasal and lung vaccine delivery remain promising approaches, but this study suggests that establishing a nasal spray as a reliable alternative will likely be difficult."

She went on to say that this is most likely due to the spray vaccine being swallowed and destroyed in the stomach rather than entering the lungs. Future research will look into whether the nasal vaccine can contain higher concentrations of ingredients that allow it to adhere to the upper respiratory tract rather than being swallowed.

This first phase 1 trial, however, found no side effects or safety issues. According to Reuters and the Financial Times, at least ten other nasal vaccines are in the development and testing stages, and India and China have already approved two such vaccines from their respective companies, Bharat Biotech and CanSino Biologics.

[This article was translated from its Greek original]