Inclusion Criteria:  Participants must be Japanese men and women and 18 to 55 years of age inclusive, at the time of signing the informed consent. Negative results from both SARS-CoV-2 qRT-PCR and serology tests Healthy by medical history, physical examination, and safety laboratory tests, according to the judgement of the investigators  Exclusion Criteria:  Fever above 37.5°C by the time when the participant is randomised; a participant excluded for transient acute illness may be dosed if the illness resolves by the time of randomisation. History of infection with SARS or MERS Any drug therapy within 7 days prior to Day 1