* the patient is expected to be discharged from the hospital within the next 24 hours. * medical condition other than the acute respiratory infection (and its manifestations) that is likely to result in death within 7 days of randomization. * use of a strong cyp3a inducer within 14 days prior to enrollment * moribund condition, defined as prior cardiac arrest during this hospitalization and life expectancy less than 48 hours of randomization. * patient undergoing comfort care measures only such that treatment focuses on end-of- life symptom management over prolongation of life. * expected inability or unwillingness to participate in study procedures. * in the opinion of the investigator, participation in a trial is not in the best interest of the patient. * allergy to investigational agent or vehicle * use of a concomitant medication that is contraindicated due to a drug-drug interaction with s-217622 * moderate to severe hepatic impairment (i.e., child-pugh class b or c) or acute liver failure. * known estimated glomerular filtration rate (egrf) \<30 ml/min/1.73m 2 * continuous renal replacement therapy or chronic dialysis * current pregnancy * current breastfeeding and unwillingness to defer breastfeeding for 30 days after the last dose of investigational agent. * women of child-bearing potential who are unwilling to abstain from sexual intercourse with men or practice appropriate contraception through 30 days from the last dose of the investigational agent. * men who are unwilling to abstain from sexual intercourse with women of child- bearing potential or to use barrier contraception through 30 days from the last dose of the investigational agent. * inability to take investigational agent in tablet form by mouth.

* the patient is expected to be discharged from the hospital within the next 24 hours. * medical condition other than the acute respiratory infection (and its manifestations) that is likely to result in death within 7 days of randomization. * use of a strong cyp3a inducer within 14 days prior to enrollment * moribund condition, defined as prior cardiac arrest during this hospitalization and life expectancy less than 48 hours of randomization. * patient undergoing comfort care measures only such that treatment focuses on end-of- life symptom management over prolongation of life. * expected inability or unwillingness to participate in study procedures. * in the opinion of the investigator, participation in a trial is not in the best interest of the patient. * allergy to investigational agent or vehicle * use of a concomitant medication that is contraindicated due to a drug-drug interaction with s-217622 * moderate to severe hepatic impairment (i.e., child-pugh class b or c) or acute liver failure. * known estimated glomerular filtration rate (egrf) \<30 ml/min/1.73m 2 * continuous renal replacement therapy or chronic dialysis * current pregnancy * current breastfeeding and unwillingness to defer breastfeeding for 30 days after the last dose of investigational agent. * women of child-bearing potential who are unwilling to abstain from sexual intercourse with men or practice appropriate contraception through 30 days from the last dose of the investigational agent. * men who are unwilling to abstain from sexual intercourse with women of child- bearing potential or to use barrier contraception through 30 days from the last dose of the investigational agent. * inability to take investigational agent in tablet form by mouth.

the patient is expected to be discharged from the hospital within the next 24 hours. medical condition other than the acute respiratory infection (and its manifestations) that is likely to result in death within 7 days of randomization. use of a strong cyp3a inducer within 14 days prior to enrollment moribund condition, defined as prior cardiac arrest during this hospitalization and life expectancy less than 48 hours of randomization. patient undergoing comfort care measures only such that treatment focuses on end-of- life symptom management over prolongation of life. expected inability or unwillingness to participate in study procedures. in the opinion of the investigator, participation in a trial is not in the best interest of the patient. allergy to investigational agent or vehicle use of a concomitant medication that is contraindicated due to a drug-drug interaction with s-217622 moderate to severe hepatic impairment (i.e., child-pugh class b or c) or acute liver failure. known estimated glomerular filtration rate (egrf) <30 ml/min/1.73m 2 continuous renal replacement therapy or chronic dialysis current pregnancy current breastfeeding and unwillingness to defer breastfeeding for 30 days after the last dose of investigational agent. women of child-bearing potential who are unwilling to abstain from sexual intercourse with men or practice appropriate contraception through 30 days from the last dose of the investigational agent. men who are unwilling to abstain from sexual intercourse with women of child- bearing potential or to use barrier contraception through 30 days from the last dose of the investigational agent. inability to take investigational agent in tablet form by mouth.

the patient is expected to be discharged from the hospital within the next 24 hours. medical condition other than the acute respiratory infection (and its manifestations) that is likely to result in death within 7 days of randomization. use of a strong cyp3a inducer within 14 days prior to enrollment moribund condition, defined as prior cardiac arrest during this hospitalization and life expectancy less than 48 hours of randomization. patient undergoing comfort care measures only such that treatment focuses on end-of- life symptom management over prolongation of life. expected inability or unwillingness to participate in study procedures. in the opinion of the investigator, participation in a trial is not in the best interest of the patient. allergy to investigational agent or vehicle use of a concomitant medication that is contraindicated due to a drug-drug interaction with s-217622 moderate to severe hepatic impairment (i.e., child-pugh class b or c) or acute liver failure. known estimated glomerular filtration rate (egrf) <30 ml/min/1.73m 2 continuous renal replacement therapy or chronic dialysis current pregnancy current breastfeeding and unwillingness to defer breastfeeding for 30 days after the last dose of investigational agent. women of child-bearing potential who are unwilling to abstain from sexual intercourse with men or practice appropriate contraception through 30 days from the last dose of the investigational agent. men who are unwilling to abstain from sexual intercourse with women of child- bearing potential or to use barrier contraception through 30 days from the last dose of the investigational agent. inability to take investigational agent in tablet form by mouth.