Attempts by researchers from the University of Oxford and AstraZeneca to create a nasal spray version of their jointly developed Covid-19 vaccine have come to a halt because initial tests in humans did not produce the desired protection. .
An antibody response in the respiratory mucous membranes was seen in only a minority of study participants, who were in the first of three usually clinical trials, the University of Oxford said in a statement Tuesday. Furthermore, the measured immune response in the blood was weaker than that of an injected vaccination.
Researchers around the world have placed high hopes on coronavirus nasal spray vaccines because the method is believed to potentially prevent infections and not just disease, as it could induce an immune response directly into the airways, where the virus enters the body. . Also, the method would be less painful and easier to handle than injections.
Regulators in India and China have already authorized products that are administered through the airways. India’s health minister approved Bharat Biotech’s Covid-19 nasal spray vaccine last month, while China’s CanSino Biologics Inclast got emergency approval from the country’s drug regulator for an inhaled version. of its COVID-19 vaccine. CanSino said studies indicated that its vaccine, administered via a nebulizer, can induce strong immunity to effectively contain the infection, while Bharat’s study results have not yet been published. The UK study enrolled 30 previously unvaccinated participants and 12 volunteers, who had previously received a standard two-dose vaccination course by injection.
“The nasal spray did not work as well in this study as we hoped,” said Sandy Douglas, lead researcher on the trial at Oxford University’s Jenner Institute. “We believe that delivering vaccines to the nose and lungs remains a promising approach, but this study suggests there are likely to be challenges in making nasal sprays a reliable option,” she added. No serious adverse events or safety concerns were reported during the AstraZeneca-funded study, according to the statement.