What is the difference between MCV (Meningococcal Conjugate Vaccine), Men B (Meningococcal B Vaccine), and Men ACWY (Meningococcal ACWY Vaccine)?

Differences Between MCV, Men B, and Men ACWY Vaccines

The key difference between these vaccines is that MCV (Meningococcal Conjugate Vaccine) and Men ACWY both protect against meningococcal serogroups A, C, W, and Y, while Men B specifically targets serogroup B which is not covered by the other vaccines. 1, 2

Meningococcal Conjugate Vaccine (MCV)

MCV refers to quadrivalent meningococcal conjugate vaccines that protect against serogroups A, C, W, and Y of Neisseria meningitidis. There are several types:

• MenACWY-D (Menactra):

  • Licensed for persons aged 9 months to 55 years
  • Contains meningococcal polysaccharides conjugated to diphtheria toxoid
  • Single 0.5-mL dose contains 4 μg each of capsular polysaccharide conjugated to approximately 48 μg of diphtheria toxoid 1

• MenACWY-CRM (Menveo):

  • Licensed for persons aged 2 months to 55 years
  • Contains meningococcal polysaccharides conjugated to CRM197 protein
  • Consists of two components: 10 μg of serogroup A polysaccharide and 5 μg each of serogroups C, Y, and W135 polysaccharides 1, 2

• MenACWY-TT (MenQuadfi):

  • Licensed for persons aged ≥2 years
  • Contains meningococcal polysaccharides conjugated to tetanus toxoid 2

Meningococcal B Vaccine (Men B)

• Specifically targets serogroup B of Neisseria meningitidis
• Not included in the quadrivalent vaccines (MCV/MenACWY)
• Important because serogroup B has been a predominant cause of invasive meningococcal disease in many countries 3
• Recommended for certain high-risk groups and during outbreaks of serogroup B disease

MenACWY Vaccine

MenACWY is simply another name for the quadrivalent meningococcal conjugate vaccines (MCV) that specifically indicates the four serogroups covered (A, C, W, and Y). The terms MCV and MenACWY are often used interchangeably when referring to quadrivalent meningococcal conjugate vaccines.

Key Clinical Considerations

• Protection coverage:

  • MCV/MenACWY vaccines: Protect against serogroups A, C, W, and Y
  • Men B vaccines: Protect only against serogroup B

• Immune response:

  • Conjugate vaccines (MCV/MenACWY) provide T-cell dependent immunity with stronger and longer-lasting protection compared to older polysaccharide vaccines 1
  • Different conjugate proteins (CRM197, diphtheria toxoid, tetanus toxoid) are used in different vaccines but all generate robust immune responses

• Administration timing:

  • For patients with asplenia, MenACWY-D should not be given before age 2 years to avoid interference with pneumococcal conjugate vaccine (PCV) 2
  • If using MenACWY-D in a person with asplenia, it should be administered either before or at least 4 weeks after completing the PCV series 2

• Target populations:

  • Routine vaccination with MenACWY is recommended for all adolescents (ages 11-18)
  • High-risk groups for both vaccines include those with complement deficiencies, asplenia, microbiologists working with N. meningitidis, and during outbreaks 1

Clinical Pitfalls to Avoid

• Don't confuse MCV with PCV: MCV refers to meningococcal conjugate vaccine, while PCV refers to pneumococcal conjugate vaccine - these target different pathogens 2

• Don't assume coverage overlap: A patient vaccinated with MenACWY is NOT protected against serogroup B disease, and vice versa

• Don't miss high-risk groups: Certain populations should receive both MenACWY and Men B vaccines, including those with complement deficiencies, asplenia, or during specific outbreaks

• Don't ignore age-specific recommendations: Different MenACWY vaccines are licensed for different age groups, and this should guide selection 1, 2