Efficacy of oral immunization against non-typable Haemophilus influenzae in man.

An oral polybacterial vaccine containing 1.5 X 10(9) killed Haemophilus influenzae per tablet stimulated salivary IgA anti H. influenzae antibody compared to placebo control groups according to statistical analysis using parameter estimates for the logistic model of best fit. Significant antibody secretion could only be demonstrated when three-monthly courses were taken, and when the H. influenzae were combined in a polybacterial mix. This latter form of H. influenzae is functionally defined as adjuvenated. Increasing the immunising dose 60 fold in the absence of the non H. influenzae bacterial species did not stimulate a detectable increase in salivary antibody.