Only a minority of participants had positive immune responses to an experimental COVID-19 vaccine administered nasally, a study published in The Lancet revealed.
Researchers using the AstraZeneca nasal vaccine also found that autoimmune responses detected were weaker than those after standard shot injections, with antibodies rarely rising higher than the level observed following the initial infection.
According to the trial, researchers gave the spray to 30 participants who had not yet been immunized against SARS-CoV-2, with 14 provided a second dose 28 days after their first. Meanwhile, another 12 received different vaccines.
“The nasal spray did not perform as well in this study as we had hoped,” lead researcher and Oxford University professor Sandy Douglas admitted. “This was quite different from recent data from China, which has suggested good results can be achieved by delivery of a similar vaccine deep into the lungs with a more complex nebulizer device.”
“We believe that delivery of 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.
According to The Hill, other companies are also developing nasally administered alternatives to their shots, with close to 100 currently in development.