GENETICALLY ENGINEERED BLEB PREPARATION ISOLATED FROM A MODIFIED NEISSERIA, MORAXELLA OR HAEMOPHILUS STRAIN AND ITS USE IN THE PREPARATION OF A VACCINE

摘要

The present invention relates to an immuno-protective and non-toxic Gram-negative bleb vaccine suitable for paediatric use. Examples of the Gram-negative strains from which the blebs are made are N. meningitidis, M. catarrhalis and H. influenzae. The blebs of the invention are improved by one or more genetic changes to the chromosome of the bacterium, including up-regulation of protective antigens, down-regulation of immunodominant non-protective antigens, and detoxification of the Lipid A moiety of LPS.