The University of Oxford has begun a phase 1 clinical trial of a nasal spray formulation of its AstraZeneca-partnered COVID-19 vaccine.
A clutch of biotechs is working on next-generation nasal and oral COVID-19 vaccines. Some of those candidates entered the clinic months ahead of the Oxford formulation, but the involvement of the researchers behind one of the first COVID-19 vaccines to come to market, at least outside of the U.S., marks a new phase in the move beyond needle-based delivery.
Investigators plan to enroll up to 30 adults aged 18 to 40 years in the study. Half of the participants will receive a single dose, with the others getting a booster dose 28 days later. The study will assess two doses, confirming safety at a low dose in six people before switching up to the standard dose.
Typical systemic reactions to intramuscular injections of the adenovirus vaccine such as aches and fever are now well understood. However, changing the route of administration could cause new local reactions at the vaccination site, such as sneezing, sore throat and nasal discharge. Intramuscular COVID-19 vaccines are associated with injection-site reactions.
Oxford’s Sandy Douglas, chief investigator of the study, said nasal delivery may bring benefits. “Some immunologists believe that delivering the vaccine to the site of infection may achieve enhanced protection, especially against transmission, and mild disease,” Douglas said in a statement. “It might also have practical advantages—nasal sprays have been used successfully for other vaccines, for example the flu vaccine used in UK schools.”
Nasal delivery may be more appealing to some people, too, potentially leading to higher uptake of the vaccine. Adrian Hill, a colleague of Douglas, added that the vaccine “could be very effective in preventing not just disease episodes but also asymptomatic infections.”
The researchers will ask participants to record their symptoms using a thermometer and e-diary for seven days after vaccination. At site visits, investigators will use strips to sample fluid from the inside of the nose. Blood and saliva samples are also part of the study.
ClinicalTrials.gov lists the study completion date as October 2021. The investigators have already received enough applications to fully enroll the study.