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Virol Res J 2017 Volume 1 Issue 3
allied
academies
International Virology Conference
October 30-31, 2017 | Toronto, Canada
R
ecent data obtainedwith live-attenuated tetravalent dengue
CYD-TDV vaccine showed moderate clinical efficacy to
DENV-2 as compared to DENV-4, while high protection rates to
both viruses were expected from previous non-human primate
experiments. Viral loads observed in naturally-infected humans
are generally much higher than those achievable in macaques
by subcutaneous or intramuscular inoculation, which may
contributetolevellingvaccineefficacy.Morestringentconditions
of infection resulting in about 100-fold increase of the viral load
were established in cynomolgus macaques and subsequently
applied to assess efficacy of CYD-TDV vaccine lots. Complete
protection (i.e. undetectable viral RNA) against DENV-4 infection
was achieved in 6/6 monkeys, while complete protection to
DENV-2, or nearly (aborted RNAemia), was observed in only
6/18 animals. All other macaques (12/18) developed DENV-
2 RNAemia curves, although below those of control animals.
Viremia parameters were found inversely correlated to pre-
challenge neutralizing antibody titers, emphasizing the key role
of these antibodies in controlling DENV infection. Moreover,
early detection of antibodies to CYD-TDV antigens in all animals
and post-challenge induction of strong anamnestic responses
suggested efficient vaccine priming, which likely contributed to
restrict DENV-2 RNAemia. Collectively, these data are in better
agreement with CYD-TDV clinical vaccine efficacy data reported
against DENV-2 and DENV-4, and demonstrate the improved
translatability of this new dengue NHP protection model.
Speaker Biography
Veronique Barban is a trained Molecular and Cellular Virologist, with 30 years of
experience in Vaccine Research in Pharmaceutical Industry. She started her career as
Research Scientist at Institut Merieux that later became Pasteur Merieux Connaught
(PMC), then Sanofi Pasteur. She was Head for 20 years of a Virology group that worked
on various human viral diseases and contributed 15 years to the development of the
1st dengue vaccine, licensed in 2015 (commercial name Dengvaxia™). Her current
position at Sanofi Pasteur is Expert in Virology in the Global Scientific Office.
e:
Veronique.Barban@sanofi.comVeronique Barban
Sanofi Pasteur, France
A new dengue non-human primate protection model with improved translation to
vaccine clinical efficacy