Influence of maternal vaccination with Tdap on children immune response

Abstract

Pertussis is an acute infectious disease of the lower respiratory tract caused by the bacterium Bordetella pertussis. The disease is highly contagious and its attack rate can reach 90% among non-immunized contacts. The introduction of vaccination was essential for the fall of over 95% in the current incidence of pertussis. However, in recent years it has been observed an overall increase in the number of pertussis cases.An alternative strategy for vaccination against pertussis is vaccination of pregnant women in the third trimester, in order to induce high titers of antibodies to pertussis in the mother and placental transfer of antibodies to the fetus, resulting in the protection of the newborn in the first months of life. In this regard, the Ministry of Health decided to include the vaccination of pregnant women against pertussis in the Brazilian immunization schedule.Despite the strategy of vaccinating pregnant women against pertussis is already used in many countries, little is known about its efficacy and effectiveness. Maternal antibodies help protect newborns from infection caused by pertussis in early life, but can also neutralize the vaccination of newborns, decreasing vaccine efficiency. Moreover, maternal immunization during pregnancy may cause transfer of antigens and cytokines to the fetus, which may induce a shift in the response profile or immunological tolerance even newborn. These aspects are particularly important and should be investigated when new maternal vaccination programs are being implemented. This study may clarify some important points, such as the best time for vaccination of pregnant women, its interference over the children vaccine response and, if so, the correlation between the children immune response and the profile and magnitude of the maternal response against B. pertussis antigens. (AU)