What is the efficacy of 2 doses of meningococcal (MenACWY/MenB) vaccines versus 3 doses for children?

From the Guidelines

The current evidence supports the use of 2 doses of MenACWY vaccine for children, as it provides sufficient protection against serogroups A, C, W, and Y, and for MenB vaccines, either a 2-dose series of Bexsero or a 3-dose series of Trumenba can be used, depending on the patient's risk for exposure and susceptibility to serogroup B meningococcal disease. The recommended schedule for MenACWY vaccine is 2 doses, with the first dose at age 11-12 years and a booster at age 16 years, which provides effective protection against serogroups A, C, W, and Y 1. For MenB vaccines, the 2-dose Bexsero series achieves adequate antibody responses comparable to the 3-dose Trumenba regimen, and the choice of dosing schedule depends on the patient's risk for exposure and susceptibility to serogroup B meningococcal disease 1.

Some key points to consider when deciding between 2 and 3 doses of meningococcal vaccines for children include:

• The conjugate technology used in MenACWY vaccines produces strong, lasting immunity, making a 2-dose schedule sufficient for most children 1
• The specific formulations of MenB vaccines determine whether 2 or 3 doses are needed for optimal protection, and the choice of dosing schedule should be based on the patient's individual risk factors 1
• The 2-dose MenACWY schedule is particularly effective in maintaining immunity through the high-risk adolescent years, and the booster dose is crucial in providing long-term protection 1

In terms of the evidence, the most recent and highest quality study supports the use of 2 doses of MenACWY vaccine for children, and either a 2-dose series of Bexsero or a 3-dose series of Trumenba for MenB vaccines, depending on the patient's risk factors 1. Overall, the 2-dose MenACWY schedule and the flexible dosing schedule for MenB vaccines provide effective protection against meningococcal disease in children, and the choice of dosing schedule should be based on individual risk factors and patient needs.

From the Research

Efficacy of 2 Doses vs. 3 Doses of Meningococcal Vaccines for Children

• The efficacy of 2 doses of meningococcal (MenACWY/MenB) vaccines versus 3 doses for children is a topic of ongoing research and debate 2, 3, 4, 5, 6.
• A study published in 2025 found that a two-dose pentavalent vaccine, with doses administered 6 months apart at 16 years of age, alongside the routinely recommended MenACWY vaccine at 11 years of age, would improve the public health impact and benefits of IMD vaccination to society 2.
• Another study published in 2019 found that one dose of quadrivalent meningococcal conjugate vaccine (MenACWY) was effective in protecting against invasive meningococcal disease (IMD), but that a booster dose at age 16 years was necessary to maintain protection 3.
• A study published in 2010 found that two doses of a meningococcal quadrivalent (A, C, W-135, Y) conjugate vaccine (MenACWY-CRM) given to infants and toddlers at 6 and 12 months was well tolerated and immunogenic, with high percentages of participants reporting hSBA titers ≥8 for all serogroups 5.
• A study published in 2014 found that a 4-dose series of MenACWY-CRM concomitantly administered with routine vaccinations to healthy infants was clinically acceptable with a similar safety profile to routine vaccines given alone 6.
• However, there is limited research directly comparing the efficacy of 2 doses vs. 3 doses of meningococcal vaccines for children, and more studies are needed to determine the optimal vaccination schedule 2, 3, 4, 5, 6.

Key Findings

• Two doses of MenACWY-CRM given to infants and toddlers at 6 and 12 months was well tolerated and immunogenic 5.
• A booster dose of MenACWY at age 16 years is necessary to maintain protection against IMD 3.
• A two-dose pentavalent vaccine, with doses administered 6 months apart at 16 years of age, alongside the routinely recommended MenACWY vaccine at 11 years of age, would improve the public health impact and benefits of IMD vaccination to society 2.

Vaccination Schedules

• The Advisory Committee on Immunization Practices (ACIP) recommends routine vaccination with MenACWY and recommends MenB vaccination under shared clinical decision-making 2, 3, 4.
• The optimal vaccination schedule for meningococcal vaccines in children is still a topic of debate and research 2, 3, 4, 5, 6.