The recent H1N1 influenza pandemic has highlighted the potential
for viral infections to cause severe disease in mothers
disproportionate to the general population and have deleterious
effects on the fetus. Vaccines have been used in pregnant women
for over 200 years. Current guidelines recommend vaccination
with only inactivated virus due to potential risk to mother and
fetus with live vaccine. The exception is during times of
pandemic or biological weapons attack, when the risk of life-
threatening disease outweighs the risk of vaccination. A paucity
of data is available regarding actual risk and mechanisms of
live viral vaccine transfer from mother to fetus. Pregnancy-
induced changes to the maternal immune system, effects of
maternal infection on neonatal immunity, and the role of the
placenta in transmission of infection and passive immunity to
the fetus are incompletely understood. The aim of this paper is
to review available data pertaining to newer vaccines such as
the pandemic H1N1 and HPV vaccines in