More about meningococcus

This page provides links to PATH's work on meningococcus and information about the disease and related vaccines.

On the PATH website

• Partnering with the World Health Organzation to develop meningococcus vaccines for Africa.

Meningococcal disease

• Meningococcus(Neisseria meningitidis) has 13 known serotypes. Groups A, B, C, Y, and W135 account for almost all cases of disease. Groups A, B, and C are the most common causes of disease worldwide.
• Meningococcal A epidemics kill several thousands of people each year in the African meningitis belt (21 countries and a population of more than 450 million).
• Meningococcal disease mainly affects infants and young children, but also can readily be found in older children and young adults.
• Up to 10 to 25 percent of a population may be asymptomatic carriers in non-epidemic settings. Most cases of meningococcal disease are acquired by person-to-person contact through droplets or contact with respiratory secretions from asymptomatic carriers.
• The most common presentation of meningococcal disease is acute meningitis characterized by fever and chills, intense headache, stiff neck, vomiting, lethargy or drowsiness, or irritability. Less commonly, patients present with meningococcal septicemia, a catastrophic constellation of fever, purpuric rash, multiorgan failure, and shock of frighteningly rapid onset.
• Meningococcal disease is treated with antibiotics. However, even with adequate antibiotic treatment, at least 10 percent of patients die within 48 hours of onset of symptoms, while 10 to 20 percent of survivors develop severe sequelae. Left untreated, the disease can lead to fatality rates greater than 50 percent. Vaccination is critical.

Meningococcal vaccine

• Multivalent polysaccharide vaccines against groups A and C, or A, C, Y, and W-135, are licensed (GSK and Sanofi-Pasteur) and available worldwide. However, most polysaccharide vaccines are poorly immunogenic in infants and children less than two years old, fail to induce immunological memory, do not induce herd immunity, and do not provide protection for more than two to three years.
• Meningococcal group C conjugate vaccines (Chiron, Wyeth, and Baxter), which are immunogenic in infants and induce long-term immune memory, are available in Europe and Canada.
• Based on the group C conjugate technology, development of a conjugate vaccine against group A meningococcal disease for developing-world mass vaccination campaigns has begun Phase 2 clinical testing with promising results.
• Development of a vaccine against group B meningococcal disease has been problematic. Several vaccine candidates are in clinical testing.

Related diseases

There are several key causes of childhood pneumonia and meningitis (inflammation of the covering of the brain), including pneumococcus, Haemophilus influenzae type b (Hib), and meningococcus bacteria. Learn more about pneumococcus. Learn more about Hib.

References

• World Health Organization. Meningococcal meningitis.
• World Health Organization. Neisseria meningitidis.
• PATH. Meningitis Vaccine Project.

Page last updated: August 2008.