Haemophilus and tetanus vaccines. Boxes & ampules of vaccines against the Haemophilus influenzae type b (lower frame) and Clostridium tetani (top centre) bacteria. H. influenzae colonises the respiratory tract during the first few months of life. Though it is usually harmless, it can cause meningitis, epiglottis, septicaemia (blood poison- ing), pneumonia or bronchitis in young children. C. tetani lives in harmlessly in the soil and human intestine but in a wound it may cause tetanus (lockjaw). The Hib & tetanus immunisations are given to young children in three intramuscular injections with a gap of a month between each.