In a University of Oxford phase 1 trial of AstraZeneca's intranasal COVID-19 vaccine candidate, the product showed "relatively weak and inconsistent measured immune responses," the researchers found.
The study, published Oct. 11 in eBioMedicine, a journal that's part of The Lancet, showed AstraZeneca's nasal vaccine was safe and tolerable but not effective against COVID-19.
Of the 30 vaccine-naive adult participants involved in the study, the most frequent side effects were sore throat, nasal discharge, headache and fatigue.
Nasal vaccines are years away from being approved by regulators and commercially available in the U.S., but multiple vaccine-makers have teamed up with university teams to develop their own candidates. Last week, Ocugen said it's partnering with Washington University in St. Louis.
The University of Oxford partners with AstraZeneca to develop the nasal vaccine candidate. One of the study's authors is an AstraZeneca employee and is named as the inventor of the vaccine's technology patent. Three other researchers also work at the U.K.-based drugmaker.
Because the early-stage study was small and did not include a placebo, the researchers concluded the development of needle-free COVID-19 vaccines "remains a priority."
In July, Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, said nasal vaccines and universal vaccines are the future of the fight against COVID-19.
"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," Sandy Douglas, PhD, the chief investigator of the study and a University of Oxford associate professor, said in a statement. "One possibility is simply that the majority of the nasal spray vaccine ends up being swallowed and destroyed in the stomach — delivery to the lungs could avoid that."