The FDA has approved an expanded indication for Sanofi's quadrivalent meningococcal vaccine MenQuadfi to include children aged 6 weeks to 23 months, marking a significant milestone in protecting the most vulnerable population against invasive meningococcal disease (IMD). The vaccine was previously approved only for individuals aged 2 years and older since April 2020.
Addressing Critical Unmet Need in High-Risk Population
"Invasive meningococcal disease remains a major global health challenge because it can strike quickly and with devastating effects, potentially taking a life in less than 24 hours," a Sanofi spokesperson stated. "As infants continue to have the highest risk of IMD, Sanofi considers it an important milestone that the US Food and Drug Administration has expanded the indication for MenQuadfi."
The approval comes at a crucial time, as Dr. Tina Tan, president of the Infectious Diseases Society of America and professor of Pediatrics at Northwestern University's Feinberg School of Medicine, noted: "We know that over the last couple of years, there has been a significant increase in the amount of meningococcal disease that's being seen here in the United States. The majority of disease seen now is serotype Y, which this vaccine contains."
Comprehensive Age Coverage and Dosing Strategy
MenQuadfi now becomes the only MenACWY vaccine that can protect individuals from 6 weeks of age with no upper age limit. The dosing regimen varies by age group:
- Infants 6 weeks to 6 months: 4-dose series at 2, 4, 6, and between 12-18 months of age, with the first dose possible as early as 6 weeks
- Infants 6-23 months: 2-dose series with the second dose in the second year of life, at least 3 months after the first dose
- Individuals 2 years and older: Single dose
The vaccine is supplied as a fully liquid solution requiring no reconstitution in single-dose vials.
Robust Clinical Evidence Supporting Approval
The expanded indication is based on comprehensive phase 3 clinical trials involving 4,321 infants ranging from 9 weeks to 19 months of age, with 1,717 infants receiving MenACWY-CRM or MenACWY-D comparator vaccines. The post-dose 4 seroresponse for MenQuadfi was similar to comparator vaccines.
Immunogenicity results demonstrated non-inferior immune responses when administered with routine pediatric vaccines compared to currently licensed MenACWY conjugate vaccines. Importantly, no unexpected safety concerns were found in infants and toddlers aged 6 weeks to 23 months compared to the safety profile in individuals aged 2 years or older.
The safety profile of 237 infants with a history of preterm birth (31-36 weeks gestational age) was comparable to full-term infants, with no new safety concerns or adverse events leading to study discontinuation.
Historical Impact and Future Implementation
Since the introduction of the first MenACWY conjugate vaccine in 2005, IMD caused by serogroups C, W, and Y has declined by approximately 90% among adolescents and young adults. The vaccine protects against Neisseria meningitidis serogroups A, C, W, and Y.
Dr. Tan emphasized the global precedent for this approach: "This is not something that is new, because there are many countries that have recommendations to give a meningococcal vaccine to the younger pediatric population to protect them."
While healthcare providers can begin using the vaccine in infants aged 6 weeks or older following FDA approval, broader implementation awaits CDC Advisory Committee of Immunization Practices (ACIP) recommendations. The ACIP is scheduled to vote on the use of MenQuadfi in infants and toddlers during their June 2025 meeting.
The CDC currently recommends meningococcal vaccination for individuals aged 2 months or older in situations where they are at increased risk for meningococcal disease, followed by regular booster doses if they remain at increased risk.
