inclusion criteria: * men and women ages 18 to 55 years, inclusive * good general health status * screening laboratory results within institutional normal range or grade 1 abnormality if the investigator documents clinical insignificance. grade 2 laboratories may be permissible if considered not clinically significant by the investigator. * for women who have not been surgically sterilized or who do not have laboratory confirmation of postmenopausal status, negative pregnancy test * willingness to practice a highly effective method of contraception * ability and willingness to comply with all aspects of the study, including nasopharyngeal swabs and blood and urine samples, through the entire study period

inclusion criteria: * men and women ages 18 to 55 years, inclusive * good general health status * screening laboratory results within institutional normal range or grade 1 abnormality if the investigator documents clinical insignificance. grade 2 laboratories may be permissible if considered not clinically significant by the investigator. * for women who have not been surgically sterilized or who do not have laboratory confirmation of postmenopausal status, negative pregnancy test * willingness to practice a highly effective method of contraception * ability and willingness to comply with all aspects of the study, including nasopharyngeal swabs and blood and urine samples, through the entire study period

inclusion criteria: - men and women ages 18 to 55 years, inclusive - good general health status - screening laboratory results within institutional normal range or grade 1 abnormality if the investigator documents clinical insignificance. grade 2 laboratories may be permissible if considered not clinically significant by the investigator. - for women who have not been surgically sterilized or who do not have laboratory confirmation of postmenopausal status, negative pregnancy test - willingness to practice a highly effective method of contraception - ability and willingness to comply with all aspects of the study, including nasopharyngeal swabs and blood and urine samples, through the entire study period

inclusion criteria: - men and women ages 18 to 55 years, inclusive - good general health status - screening laboratory results within institutional normal range or grade 1 abnormality if the investigator documents clinical insignificance. grade 2 laboratories may be permissible if considered not clinically significant by the investigator. - for women who have not been surgically sterilized or who do not have laboratory confirmation of postmenopausal status, negative pregnancy test - willingness to practice a highly effective method of contraception - ability and willingness to comply with all aspects of the study, including nasopharyngeal swabs and blood and urine samples, through the entire study period