A preliminary clinical trial on a nasal formulation of an anti-covid vaccine led by the University of Oxford in collaboration with the British laboratory AstraZeneca has failed, according to a press release on Tuesday.
Oxford believes that this study is the first to be published on an adenovirus vector vaccine by nasal spray.
The researchers only observed an antibody response in the nasal mucosa "in a minority of participants", explains the University of Oxford.
The “systemic immune response to intranasal vaccination was also weaker than during intramuscular vaccination,” the statement added.
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“This nasal spray didn't work as well as we hoped,” commented Sandy Douglas, associate professor at the university who participated in the trial.
She points out that a study in China had good results with a more complex spray that sends the vaccine deeper into the lungs, and therefore believes that it is possible that a large part of the vaccine tested by the British university is fallen into the digestive tract with the more summary nasal spray used.
The promises of nasal administration
The study used the same adenovirus vector that is used for the vaccine developed by Oxford with AstraZeneca, one of the very first covid serums introduced to the market at the height of the pandemic.
“Giving vaccines through the nose and airways is one of the most promising ways to achieve immunity” and “could end mild covid infections and transmission of the virus more effectively than injected vaccines” , notes Adam Ritchie, one of the leaders of the Oxford vaccine program.
This also has the advantage of “avoiding the use of a needle.
Many parents know that nasal sprays are already used for flu shots offered to schoolchildren in some countries, including the UK,” he adds.