As with other vaccines, the administration of Meningococcal polysaccharide vaccine should be postponed in subjects suffering from acute severe febrile illness. The presence of a minor infection, however, is not a contraindication for immunization. This vaccine gives no protection against meningococcal meningitis caused by meningococci belonging to serogroups other than A, C, W135 and Y. If administered to subjects with impaired immune responses, the vaccine may not induce an effective response. As with all injectable vaccines, appropriate medication (e.g. adrenaline) should always be readily available for treatment in case of anaphylactic reactions following the administration of the vaccine. Lactation: Adequate data on the administration of this vaccine to women who are breast-feeding are not available. This vaccine should be administered to women who are breast-feeding when needed and the possible advantages outweigh the possible risks.