Attempts by Oxford University researchers and AstraZeneca Plc. to create a nasal-spray version of their jointly developed COVID-19 shot suffered a setback on Tuesday as initial testing on humans did not yield the desired protection.
An antibody response in the respiratory mucous membranes was seen in only a minority of participants in the trial, which was in the first of usually three phases of clinical testing, the University of Oxford said in a statement on Tuesday.
Also, the immune response measured in the blood was weaker than that from a shot-in-the-arm vaccination.
Researchers across the world have placed high hopes on nasal spray vaccines against the coronavirus because the method is believed to potentially prevent infection and not just disease as it may prompt an immune response directly in the airways, where the virus enters the body….