Do not use Act-HIB 10 micrograms/0.5 ml powder and solvent for solution for injection in pre-filled syringe: If child is allergic (hypersensitive) to any of vaccine components (listed in Description), to the tetanus protein, to formaldehyde, or if child had an allergic reaction following injection of a vaccine containing the same substances; If child had an allergic reaction following prior injection of a Haemophilus influenzae type b conjugate vaccine; If child has a fever or a disease that occurred suddenly, without warning (acute disease), in this case it is preferable to postpone the vaccination.