Meningococcal Disease: Strains, Vaccines & Evidence

Epidemiology of bacterial meningitis, the major serogroups (A, B, C, W, Y), available vaccines for each, and recommendation rationale for adolescents and college students.

Bacterial Vaccines Available Adolescents at Risk

Disease Overview & Transmission

Meningococcal disease refers to infections caused by the bacterium Neisseria meningitidis, also known as the meningococcus. The most common presentations are meningococcal meningitis (inflammation of the membranes surrounding the brain and spinal cord) and meningococcemia (blood poisoning).

Meningococcal disease progresses rapidly and can lead to death within 24-48 hours even with appropriate antibiotic treatment. Among survivors, 10-20% suffer long-term sequelae including hearing loss, neurological damage, limb amputations, and skin scarring.

U.S. Disease Burden

  • ~600-1,000 cases annually in recent years
  • 10-15% case fatality rate
  • 10-20% of survivors have permanent disabilities
  • Highest incidence in infants, adolescents, and young adults

Meningococcal Serogroups

N. meningitidis is classified into 12 serogroups based on its polysaccharide capsule. Five serogroups (A, B, C, W, Y) cause the vast majority of disease worldwide.

Serogroup A

Historically caused large epidemics in sub-Saharan Africa ("meningitis belt"). Now rare in U.S. with routine vaccination.

conjugate vaccine available

Serogroup B

Currently the most common cause of meningococcal disease in U.S. and Europe. Requires special vaccine (not polysaccharide-based).

protein-based vaccine

Serogroup C

Second most common in U.S. Often causes localized outbreaks in communities and college campuses.

conjugate vaccine available

Serogroup W

Emerging strain causing increased disease in some regions, including the UK and parts of Africa.

conjugate vaccine available

Serogroup Y

Accounted for increasing proportion of U.S. cases in recent years, along with W.

conjugate vaccine available

Available Vaccines & Effectiveness

MenACWY Vaccines (Conjugate)

Menactra®

Sanofi Pasteur. Quadrivalent (A, C, W, Y). FDA approved 2005.

Menveo®

GSK. Quadrivalent (A, C, W, Y). FDA approved 2010.

MenQuadfi®

Sanofi Pasteur. Quadrivalent (A, C, W, Y). FDA approved 2020.

MenB Vaccines (Protein-based)

Trumenba® (MenB-FHbp)

Pfizer. Two-dose or three-dose series. FDA approved 2014.

Bexsero® (MenB-4C)

GSK. Two-dose or three-dose series. FDA approved 2015.

Vaccine Effectiveness

  • MenACWY: 80-85% effective at preventing disease from included serogroups
  • MenB: 70-80% effective against MenB strains covered by the specific vaccine
  • Protection lasts at least 5 years for most recipients

ACIP Recommendations

  • Routine MenACWY at 11-12 years, booster at 16 years
  • College students living in dorms (consider MenB)
  • High-risk groups (asplenia, complement deficiency, microbiologists)
  • Outbreak response (any serogroup)

Sources & Citations

  • CDC. (2023). Meningococcal Disease - Surveillance & Vaccination. cdc.gov/meningococcal
  • CDC. (2023). Meningococcal ACIP Vaccine Recommendations. CDC ACIP
  • WHO. (2022). Meningococcal Meningitis - Fact Sheet. who.int

Related Pages