Frequency of vaccine-related reactogenicity events (REs) that occur during the acute monitoring phase of the study (Days 0 to 10 for adult and seropositive groups, Days 0 to 28 for seronegative groups) Throughout study [clinicaltrials_resource:c590279c48348c96d7a25752a00ffbda]

One vaccination with rB/HPIV3 vaccine (at higher dose) given as nose drops to adults 18 to 49 years of age

Frequency of vaccine-related reactogenicity events (REs) that occur during the acute monitoring phase of the study (Days 0 to 10 for adult and seropositive groups, Days 0 to 28 for seronegative groups) Throughout study [clinicaltrials_resource:c590279c48348c96d7a25752a00ffbda]

One vaccination with rB/HPIV3 vaccine (at higher dose) given as nose drops to adults 18 to 49 years of age