Neiserria meningitidis is an endemic cause of invasive disease in Canada and may have devastating consequences. There are a number of serotypes (A, B, C, Y, W-135) that cause disease. Serotype A is relatively uncommon and is primarily a risk for travellers to endemic areas. Serotype B is currently the most common cause of disease in Canada. Serogroup C can cause sporadic cases of disease and community outbreaks but these have been significantly reduced since implementation of universal infant protein-polysaccharide meninococcal-C vaccination in Canada. Serogroups Y and W135 are relatively uncommon causes of sporadic cases.
Unfortunately, no currently available vaccine protects against serotype-B. Polysaccharide meningococcal A, C, Y, W-135 vaccine has been available for decades but has been largely replaced by protein-polysaccharide conjugate vaccines in recent years. This is because unlike polysaccharide vaccines, conjugate vaccines are efficacious in infants and young children and they induce immune memory. Current recommendations are that all infants and children should be immunized with conjugate meningococcal-C vaccine and that one dose of quadrivalent (A, C, Y, W-135) conjugate vaccine be given routinely in adolescence. Immunization with quadrivalent conjugate vaccine is also recommended for certain individuals with immune deficiencies including those with antibody and complement deficiencies and asplenics, and other selected people who are at increased risk such as travellers to endemic areas, during outbreaks and in those who may face occupational exposure.