London - (AFP) - A preliminary clinical trial of a nasally administered COVID-19 vaccine, conducted by the University of Oxford in collaboration with the British laboratory AstraZeneca, failed, according to a statement issued on Tuesday.
Oxford estimates that this study is the first to be published on a nasal spray adenoviral vaccine.

The researchers did not notice an antibody response in the nasal mucosa except in a “minority of the participants,” according to the University of Oxford.

The statement added that the "systematic" immune response to intranasal vaccination was also weaker compared to intramuscular vaccination.

"The nasal spray did not work as well as we had hoped," said Sandy Douglas, a university professor involved in the trial.

She pointed out that a study in China had achieved good results using a more complex spray that sent the vaccine deeper into the lungs, and therefore it was considered that a large part of the vaccine tested by the British University might have ended up in the digestive system.

The study used the adenovirus vector used in the vaccine Oxford developed with AstraZeneca, one of the first coronavirus vaccines that came to market at the height of the pandemic.

"Intranasal and airway administration of vaccines is one of the most promising ways to achieve immunity," said Adam Ritchie, one of the heads of the Vaccine Programs at Oxford University. .

He pointed out that one of its advantages is also "avoiding the use of the needle." "Many parents know that nasal sprays are used in influenza vaccines given to schoolchildren in some countries, including the UK," he said.

The experiment included thirty people who had not been vaccinated before.