INTRODUCTION: RV3 is a human neonatal rotavirus strain (G3P[6]) that has been 
associated with asymptomatic neonatal infection and replicates well in the 
infant gut. RV3-BB rotavirus vaccine has been developed as a rotavirus vaccine 
candidate for administration at birth.
METHODS: A single-centre, double-blind, randomised placebo-controlled Phase I 
study evaluated the safety and tolerability of a single oral dose of the second 
generation RV3-BB rotavirus vaccine (8.3×10(6)FFU/mL) in 20 adults, 20 children 
and 20 infants (10 vaccine and 10 placebo per age cohort). Vaccine take was 
defined as seroconversion (a 3-fold increase in serum anti-rotavirus IgA or 
serum neutralising antibody (SNA) from baseline at day 28 post-dose) or evidence 
of RV3-BB viral replication in the faeces by RT-PCR analysis 3-6 days 
post-vaccination. RV3-BB presence was confirmed by sequence analysis.
RESULTS: The RV3-BB vaccine was well tolerated in all participants, with no 
pattern of adverse events shown to be associated with the study vaccine. In the 
infant cohort, vaccine take was demonstrated in 8/9 infants following a single 
dose of vaccine compared with 2/7 placebo recipients. In the infant vaccine 
group, 5/9 infants exhibited either IgA or SNA seroconversion and 7/9 infants 
had evidence of RV3-BB replication on days 3-6, compared with 2/7 infants who 
seroconverted and 0/10 infants with evidence of replication in the placebo 
group. Two infants in the placebo group had serological evidence of a rotavirus 
infection within the 28-day study period: one demonstrated an IgA and the other 
an SNA response, with wild-type virus replication detected in another infant.
CONCLUSION: A single dose of RV3-BB rotavirus vaccine was well tolerated in 
adults, children and infants. Most infants (8/9) who received RV3-BB 
demonstrated vaccine take following a single dose. These data support 
progression of RV3-BB to Phase II immunogenicity and efficacy trials.