 AstraZeneca PLC LSE:AZN noted that attempts by the company and Oxford University researchers to create a nasal-spray version of their jointly developed COVID-19 shot has suffered a setback 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. 