The RV3-BB human neonatal rotavirus vaccine aims to provide protection from 
severe rotavirus disease from birth. A phase IIa safety and immunogenicity trial 
was undertaken in Dunedin, New Zealand between January 2012 and April 2014. 
Healthy, full-term (≥ 36 weeks gestation) babies, who were 0-5 d old were 
randomly assigned (1:1:1) to receive 3 doses of oral RV3-BB vaccine with the 
first dose given at 0-5 d after birth (neonatal schedule), or the first dose 
given at about 8 weeks after birth (infant schedule), or to receive placebo 
(placebo schedule). Vaccine take (serum immune response or stool shedding of 
vaccine virus after any dose) was detected after 3 doses of RV3-BB vaccine in 
>90% of participants when the first dose was administered in the neonatal and 
infant schedules. The aim of the current study was to characterize RV3-BB 
shedding and virus replication following administration of RV3-BB in a neonatal 
and infant vaccination schedule. Shedding was defined as detection of rotavirus 
by VP6 reverse transcription polymerase chain reaction (RT-PCR) in stool on days 
3-7 after administration of RV3-BB. Shedding of rotavirus was highest following 
vaccination at 8 weeks of age in both neonatal and infant schedules (19/30 and 
17/27, respectively). Rotavirus was detected in stool on days 3-7, after at 
least one dose of RV3-BB, in 70% (21/30) of neonate, 78% (21/27) of infant and 
3% (1/32) placebo participants. In participants who shed RV3-BB, rotavirus was 
detectable in stool on day 1 following RV3-BB administration and remained 
positive until day 4-5 after administration. The distinct pattern of RV3-BB 
stool viral load demonstrated using a NSP3 quantitative qRT-PCR in participants 
who shed RV3-BB, suggests that detection of RV3-BB at day 3-7 was the result of 
replication rather than passage through the gastrointestinal tract.