IFNG and bronchiectasis: Data in support of this strategy showed that in children with bronchiectasis, the capacity to produce IFN-γ in response to NTHi was highest in those who had received three or more doses of a pneumococcal conjugate vaccine that contained H. influenzae protein D (PHiD-CV) (51), a surface protein expressed by H. influenzae, not present in the HiB vaccine (52).