Cincinnati Children's Hospital Medical Center on Friday reported encouraging results from the first human clinical trial to be conducted in the United States of a nasal COVID vaccine.

Findings from the study led by an expert at Cincinnati Children's were published on 4 July 2025 in Science Advances. The vaccine is made by Georgia-based company CyanVac LLC, which also funded the clinical trial. Based on the promising data generated from this phase 1 trial, two larger clinical studies involving more people are underway. If these trials also prove successful, the CVXGA vaccine could join four other nasal COVID vaccines approved in other countries: two in China, one in Russia, and another in India.

The clinical trial included 72 people who received vaccinations, with ages ranging from 12 to 53. A total of 61 participants completed the entire trial. During the period of the trial from September 2021 to May 2023, various waves of SARS-CoV-2 variant infections emerged in the United States.

Participants were divided among four groups. One group received a low dose of the vaccine, which served as a control group. The other three higher dose groups included one group of adults that had never been infected or had not been vaccinated recently; a group of adults that had been recently vaccinated with a previous mRNA vaccine; and a group of teens that also had been vaccinated. The researchers found evidence that the vaccine was absorbed in the nasal tissues, and that it generated statistically significant antibody responses, as intended.

The largest of the two ongoing trials seeks to enrol up to 10,016 participants by mid-2026 with the study completed by mid-2027.

While the traditional way to administer protection has been to inject vaccines into the bloodstream, many experts called for developing a nasally delivered vaccine as a potentially more-effective approach.