Influence of pregnant women\'s Tdap vaccination in the child\'s immunological response profile against Bordetella pertussis

Author(s)

Carolina Argondizo Correia

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Medicina Tropical de São Paulo (IMT)
• Defense date: 2018-04-11

Examining board members

Cyro Alves de Brito; Hiro Goto; Patricia Palmeira Daenekas Jorge; Lily Yin Weckx

• Advisor: Cyro Alves de Brito

Abstract

Bordetella pertussis is the bacterial agent of whooping cough, an infectious and contagious re-emerging disease despite high vaccine coverage. As the most affected are children younger than six months of age, a dose of tetanus/diphtheria/pertussis vaccine (acellular pertussis - Tdap) in pregnancy was proposed. It is aimed to promote the transfer of high maternal antibodies\' titres to the foetus and newborns, resulting in their protection until their own vaccination scheme is completed. This strategy is present in several countries, and it was implemented in Brazil by the end of 2014. However, little is known about its efficacy, effectiveness and interaction with the subsequent child\'s vaccination, which comprehends the whole-cell formulation (DTP), while other countries replaced it for the acellular version (DTaP). Maternal vaccination induces antibodies that would protect newborns from infection, but they can also neutralize the effect of the child vaccination, reducing the vaccine efficiency. Besides, it can promote the transfer of antigens to the foetus, which can induce deviation in the response pattern. These aspects are particularly important and should be investigated when new maternal vaccination programs are implemented. Therefore, the aim of this project was to evaluate the cellular response against B. pertussis in women at labour and their neonates, as in young children after complete pertussis vaccination by the first year of life, comparing groups from vaccinated and non-vaccinated women during pregnancy. Peripheral blood and cord blood mononuclear cells were isolated and stimulated with bacterial or polyclonal antigen in culture. After the stipulated time the gene expression profile and cytokine concentration were evaluated by qPCR and flow cytometry. Data from the present study show that pregnancy vaccination inducing favourable cellular response for protection against infection in pregnant women, with Th1 cytokines\' production upon antigenic stimulus, while in newborns few cytokines were detected above the detection limit. When comparing children\'s response, born either from vaccinated or unvaccinated mothers, cytokine levels were not significantly different, suggesting that maternal antibodies present during foetal development and first months of life do not interfere with recognition and cellular response generation to vaccination. Despite limited sample size, this work shows a broader view of interaction between maternal and child vaccination, showing that the Tdap boost dose during pregnancy may be able to generate protective response in women, preventing them to transmit the disease to children, and the induced humoral response may not interfere in generating cellular response in children after their own vaccination. (AU)

• FAPESP's process: 15/19726-7 - Influence of the DTPa vaccination in pregnant women in the type of immunological response against Bordetella pertussis in children
• Grantee: Carolina Argondizo Correia
• Support Opportunities: Scholarships in Brazil - Master