Meningococcal vaccines [Meningokok aşilari]

Meningococcal disease, presenting primarily as meningococcemia and meningitis, continues to be a devastating problem around the world. In the past 200 years, several meningococcal epidemics have been noted in Europe, Africa, Asia, and the United States. Annually, 500.000 cases of invasive meningococcal disease occur still worldwide, of which ?50.000 result in death. Therefore, vaccine development has been undertaken in earnest for the prevention of this disease. Polysaccharide vaccines have been available for almost 40 years, yet they are poorly immunogenic in young children who are at the highest risk. Therefore, routine vaccination with polysaccharide vaccines is not recommended. A mass-immunization program with meningococcal C conjugate vaccine (MCV) was initiated in 1999 in the United Kingdom. Since its introduction into some routine immunization schedules, MCV has proven tobe efficacious. An 81% reduction in the number of confirmed cases of invasive meningococcal disease has been observed following routine immunization. A tetravalent polysaccharide-protein conjugate vaccine [MCV-4] against serogroups A, C, W135 and Y, has been introduced in the USA in 2005. The Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination of preadolescents (at ages of 11-12 years) with MCV-4. For persons who had not been vaccinated previously, ACIP recommended vaccination before high-school entry (approximately at the age of 15 years). MCV-4 has been shown to have comparable immunogenicity and similar adverse reaction profile to the tetravalent meningococcal polysaccharide vaccine (MPSV4). It is expected that MCV4 has better immunogenicity among persons in other age groups (infants and children aged <10 years) than MPSV4. However, development of effective strategies to control serogroup B meningococcal disease is still needed for comprehensive control of meningococcal disease.