How many doses of Bexsero (Meningococcal B vaccine) are recommended for an infant starting the vaccine series at less than 6 months old?

Bexsero Dosing for Infants Starting Before 6 Months of Age

Bexsero is not licensed for use in infants under 10 years of age in the United States, so any use in infants less than 6 months old would be off-label. 1

Critical Licensing Information

• Bexsero (MenB-4C) is only FDA-licensed for persons aged 10-25 years in the United States 1
• The vaccine has been used in other countries (UK, Europe, Canada, Australia) in infant immunization programs, but this represents international practice, not US-approved indications 2, 3, 4

International Infant Schedules (For Reference Only)

While not applicable to US practice under current FDA licensing, international programs have used the following schedules in infants:

UK Reduced Schedule

• 2 primary doses at 2 and 4 months of age, followed by a booster at 12 months 3, 4
• This reduced schedule achieved 95.5% coverage for one dose and 88.6% for two doses by 6 months of age 4
• Two-dose vaccine effectiveness was 82.9% against all MenB cases 4

Standard Infant Schedule (Other Countries)

• 3 primary doses administered at 2,3, and 4 months OR 2,4, and 6 months of age 2
• A booster dose at 12 months of age in vaccine-experienced infants elicited robust immunogenic responses 2

US-Licensed Dosing (Age ≥10 Years Only)

For Healthy Adolescents (16-23 years, shared clinical decision-making)

• 2-dose series at 0 and 6 months 1, 5

For High-Risk Persons (≥10 years)

• 3-dose series at 0,1-2, and 6 months 1, 5
• This applies to persons with complement deficiencies, asplenia, complement inhibitor use, microbiologists, or outbreak settings 1

Key Clinical Pitfalls

• Do not confuse Bexsero with MenACWY vaccines (Menveo, Menactra), which ARE licensed for infant use starting at 2 months of age 1
• The two MenB vaccines (Bexsero and Trumenba) are not interchangeable - the same product must be used for all doses 1
• Bexsero causes high rates of fever in infants - international programs recommend prophylactic paracetamol (3 doses) when used in infants 3
• The updated 2024 FDA label for Bexsero now aligns the dosing schedule with Trumenba (0 and 6 months for healthy adolescents; 0,1-2, and 6 months for high-risk) 5