Background: Virus-associated febrile lower respiratory tract infections (fLRIs) during infancy have been identified as risk factors for persistent wheeze development. We hypothesized that variations in innate immune defense capacity during this period, as exemplified by production of type 1 and 3 interferons (T1/3IFNs), might be an underlying determinant of risk.
Objective: We sought to investigate relationships between postnatal development of innate interferon response capacity and susceptibility to early infections and persistent wheeze.
Background: Several previous studies have highlighted the strong Th2-polarising and IgE-promoting activity of the DTaP vaccine, but there is no evidence that this has pathological consequences and accordingly there is no current interest amongst vaccine developers in reformulating DTaP to attenuate these properties. In light of an apparent resurgence in pertussis in many countries, and emerging evidence from other areas of paediatric immunology of IgE-mediated interference with host defence mechanisms, this issue requires more detailed clarification.
Methods: We have re-evaluated the impact of DTaP-only versus mixed DTwP/DTaP vaccination on Th2-dependent "bystander" IgE responses in three cohorts of children under different priming conditions, encompassing both vaccine-targeted and unrelated antigens including food allergens.