What is the difference between MCV (Meningococcal Conjugate Vaccine), MenB (Meningococcal B Vaccine), and MenACWY (Meningococcal Conjugate Vaccine against serogroups A, C, W, and Y)?

Differences Between MCV, MenB, and MenACWY Vaccines

The key difference between these meningococcal vaccines is that MenB targets only serogroup B while MenACWY targets serogroups A, C, W, and Y; MCV is a general term for meningococcal conjugate vaccines that typically refers to MenACWY vaccines.

Vaccine Types and Composition

MenACWY (Meningococcal Conjugate Vaccine)

• Protects against meningococcal serogroups A, C, W, and Y
• Available as three licensed vaccines in the US 1:
  • MenACWY-D (Menactra): Licensed for ages 9 months-55 years
  • MenACWY-CRM (Menveo): Licensed for ages 2 months-55 years
  • MenACWY-TT (MenQuadfi): Licensed for ages ≥2 years
• Composition: Capsular polysaccharides from serogroups A, C, W, and Y conjugated to carrier proteins 2
• MenACWY-CRM specifically contains:
  • 10 μg of serogroup A polysaccharide conjugated to CRM197
  • 5 μg each of serogroups C, Y, and W135 polysaccharides conjugated to CRM197 2

MenB (Meningococcal B Vaccine)

• Specifically targets serogroup B meningococcal disease
• Available as two vaccines 3:
  • MenB-4C (Bexsero)
  • MenB-FHbp (Trumenba)
• Uses protein-based antigens rather than polysaccharide capsules 4
• These vaccines are not interchangeable - the same product must be used for all doses 2

MCV (Meningococcal Conjugate Vaccine)

• MCV is a general term often used to refer to meningococcal conjugate vaccines
• In most contexts, MCV4 refers to quadrivalent meningococcal conjugate vaccines (MenACWY) 2
• The term "MCV" is sometimes used interchangeably with "MenACWY" in clinical practice

Key Differences in Protection

1. Target Serogroups:

   • MenB: Only protects against serogroup B
   • MenACWY: Protects against serogroups A, C, W, and Y
   • MCV: Generally refers to conjugate vaccines against multiple serogroups (typically A, C, W, Y)

2. Vaccine Technology:

   • MenB: Uses subcapsular protein-based antigens 4
   • MenACWY: Uses capsular polysaccharides conjugated to carrier proteins 2

3. Testing Methods:

   • MenB: Evaluated using human serum bactericidal antibody (hSBA) assays 4
   • MenACWY: Can be evaluated using rabbit serum bactericidal antibody (rSBA) assays 4

Clinical Recommendations

• MenACWY is recommended for all persons aged 11-18 years and for persons aged 2-55 years at increased risk for meningococcal disease 2
• MenB vaccines are approved for use in persons aged 10-25 years 2
• For persons at increased risk (complement deficiencies, asplenia, etc.), both MenACWY and MenB vaccines are recommended 2, 3
• A pentavalent vaccine (MenACWY-TT/MenB-FHbp) is now available that protects against all five serogroups (A, B, C, W, Y) 3, 5

Important Considerations

• Immunity wanes over time, particularly for serogroup A, with only 3-11% of children maintaining protective antibody levels 5 years after infant immunization with MenACWY-CRM 6
• When administering both types of vaccines, MenACWY and MenB can be given concomitantly but at different anatomical sites 2
• For high-risk patients with asplenia, MenACWY-D should not be given before age 2 years and should be administered either before or at least 4 weeks after completing PCV13 series to prevent immune interference 1

Pitfalls to Avoid

• Do not confuse PCV (pneumococcal conjugate vaccine) with meningococcal vaccines - they target different pathogens 1
• Do not interchange different MenB vaccines in a vaccination series 2
• Do not assume that MenACWY provides protection against serogroup B disease, which is common in many countries 2
• Be aware that protection against different serogroups wanes at different rates, with serogroup A immunity declining most rapidly 6