As similar local evidence recently available, present study will not add new information; no ethical justification exists to continue study procedures.

The purpose of the study is to support the recommendation of vaccination of all pregnant women in Colombia with Diptheria, tetanus and pertussis (dTpa) by studying the transfer of pertussis specific IgG antibodies from mother to the child.

This study will assess the immunogenicity in infants (at birth and just prior to primary pertussis vaccination [i.e. diphtheria, tetanus and pertussis [DTP] vaccination] administered at 8 weeks of age), of a single Boostrix booster dose administered to their mothers during the second or third trimester as per routine practice in Bogota, Colombia.

Inclusion Criteria:

Criteria applicable at screening (before the birth of the infant):

• Male or female infants whose mothers have received Boostrix during their current pregnancy, as per routine practice.
• Infant whose parents, in the opinion of the investigator, can and will comply with the requirements of the protocol.
• Written informed consent obtained from both parents of the infant.

Criteria applicable at enrolment (after the birth of the infant):

• Confirmation of written informed consent obtained from both parents of the infant at the time of screening.
• Infant whose parents, in the opinion of the investigator, can and will comply with the requirements of the protocol.

Exclusion Criteria:

Criteria applicable at screening (before the birth of the infant):

• Infants whose parents are below the legal consenting age of the country.
• Infant's whose mother has multiple pregnancies.
• Infant's whose mother has any confirmed or suspected immunosuppressive or immunodeficient condition (including positive infection with human immunodeficiency virus [HIV]), based on medical history, physical examination or positive test result.
• Infant's whose mother is concurrently participating in another clinical study, at any time during the study period, in which the infant's mother has been or will be exposed to an investigational or a non-investigational vaccine/product.

Criteria applicable at enrolment (after the birth of the infant):

• Child in care.
• In case of multiple births.
• Infants with any confirmed or suspected immunosuppressive or immunodeficient condition , based on medical history, physical examination or positive test result.
• Infants who are concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational vaccine/product.

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.