- subject has an underlying condition that may interfere with intranasal administration of the imp (e.g., chronic ulcers in the nose). - subject has symptoms suggesting engagement of the lower respiratory tract or a systemic engagement - subject has an active or acute infection other than sars-cov-2 - subject has another member of the same household recruited to this study

- subject has an underlying condition that may interfere with intranasal administration of the imp (e.g., chronic ulcers in the nose). - subject has symptoms suggesting engagement of the lower respiratory tract or a systemic engagement - subject has an active or acute infection other than sars-cov-2 - subject has another member of the same household recruited to this study