Nimenrix is a vaccine used to protect adults, adolescents and children from the age of 6 weeks against invasive meningococcal disease caused by four groups of the bacterium neisseria meningitidis (group a, c, w-135, and y). invasive disease occurs when the bacteria spread through the body causing serious infections such as meningitis (infection of the membranes that surround the brain and spine) and septicaemia (blood poisoning). in children from 6 to 12 weeks of age, three doses of nimenrix are recommended (the first dose is given from 6 weeks of age, thesecond dose 2 months afterwards, and the third booster dose at 1 year of age). in adults and children from 1 year of age, one injection is usually given. nimenrix may also be used as a booster vaccine in people from 1 year of age who have already been vaccinated with nimenrix or another meningococcal vaccine, to reinforce the level of protection.