Pertussis Immunization During Pregnancy: Effect in Term and Preterm Infants
Status:
Active, not recruiting
Trial end date:
1969-12-31
Target enrollment:
Participant gender:
Summary
Young infants are most vulnerable to severe disease and even death when infected with
Bordetella Pertussis. The current vaccines and vaccination programs do not guarantee
protection of neonates. During the last weeks of pregnancy, maternal IgG antibodies are
transferred actively to the fetus. Administration of a pertussis containing vaccine during
pregnancy offers protection through high titers of maternal antibodies transferred to the
child. Since transplacental transport is immature, infants who are born prior to 37 weeks of
gestation, might be vulnerable to pertussis infection even though maternal vaccination was
administered, but specific data are lacking. The primary aim of this observational study is
to measure whether vaccination during pregnancy offers protection to preterm born infants
through higher titers of maternal antibodies, despite immature transplacental transport. Four
cohorts of mother-infant pairs will be recruited: term versus preterm born infants, born from
either vaccinated women or not vaccinated women. These mother-infant pairs are recruited
according to the vaccination status of the mother and to the gestational age at delivery.
Pertussis specific antibody titers (anti-Pertussis Toxin, anti-Filamentous haemagglutinin,
anti-Pertactin titers) will be monitored in blood samples of the mothers at delivery to
measure the possible influence of both gestational age and maternal vaccination status. In
order to measure the decline of maternal antibodies in the first weeks of life, blood will be
taken from cords as well as from infants at 8 weeks of age, before the first infant pertussis
vaccine is administered.
Pertussis antibodies to the same antigens will be measured in all infants after a primary
series of acellular pertussis vaccines administered at 8,12 and 16 weeks of age and before
and after a booster dose in the second year of life.
In addition, cellular mediated immune responses will be evaluated in a subgroup of infants
before and after a primary series of infants vaccines. A last goal is to measure whether
vaccination during pregnancy could offer additional maternal antibodies through breast milk.
Again a comparison is made between preterm and term born infants, born from either vaccinated
or unvaccinated women. The amount of lactoferrin and pertussis toxin specific IgA in breast
milk samples will be measured in samples taken at birth (colostrum), and at several time
points afterwards as long as breastfeeding is continued.
Details
Lead Sponsor:
Universiteit Antwerpen
Collaborators:
Research Foundation Flanders Université Libre de Bruxelles University Hospital, Antwerp