* current tracheostomy or laryngectomy; * concomitant respiratory therapy such as oxygen or ventilatory support. positive airway pressure for obstructive sleep apnea is permitted if treatment was established with good compliance at least 3 months before enrolment; * need for hospitalization for any reason; * inability to safely self-administer nasal irrigation * any clinical contraindications, as judged by the qualified medical practitioner; * clinical signs indicative of moderate, severe or critical covid severity symptoms (as defined by fda covid-19 guidance document) * mentally or neurologically disabled patients who are considered not fit to consent to their participation in the study; * lactating, pregnant or planning to become pregnant during the study period; * diagnosed with prior covid-19 infection (\>48 hours from the time the test is reported prior to the time of screening).

* current tracheostomy or laryngectomy; * concomitant respiratory therapy such as oxygen or ventilatory support. positive airway pressure for obstructive sleep apnea is permitted if treatment was established with good compliance at least 3 months before enrolment; * need for hospitalization for any reason; * inability to safely self-administer nasal irrigation * any clinical contraindications, as judged by the qualified medical practitioner; * clinical signs indicative of moderate, severe or critical covid severity symptoms (as defined by fda covid-19 guidance document) * mentally or neurologically disabled patients who are considered not fit to consent to their participation in the study; * lactating, pregnant or planning to become pregnant during the study period; * diagnosed with prior covid-19 infection (\>48 hours from the time the test is reported prior to the time of screening).

- current tracheostomy or laryngectomy; - concomitant respiratory therapy such as oxygen or ventilatory support. positive airway pressure for obstructive sleep apnea is permitted if treatment was established with good compliance at least 3 months before enrolment; - need for hospitalization for any reason; - inability to safely self-administer nasal irrigation - any clinical contraindications, as judged by the qualified medical practitioner; - clinical signs indicative of moderate, severe or critical covid severity symptoms (as defined by fda covid-19 guidance document) - mentally or neurologically disabled patients who are considered not fit to consent to their participation in the study; - lactating, pregnant or planning to become pregnant during the study period; - diagnosed with prior covid-19 infection (>48 hours from the time the test is reported prior to the time of screening).

- current tracheostomy or laryngectomy; - concomitant respiratory therapy such as oxygen or ventilatory support. positive airway pressure for obstructive sleep apnea is permitted if treatment was established with good compliance at least 3 months before enrolment; - need for hospitalization for any reason; - inability to safely self-administer nasal irrigation - any clinical contraindications, as judged by the qualified medical practitioner; - clinical signs indicative of moderate, severe or critical covid severity symptoms (as defined by fda covid-19 guidance document) - mentally or neurologically disabled patients who are considered not fit to consent to their participation in the study; - lactating, pregnant or planning to become pregnant during the study period; - diagnosed with prior covid-19 infection (>48 hours from the time the test is reported prior to the time of screening).