Summary of NACI statement of May 2026: Update on the use of quadrivalent conjugate meningococcal vaccines in children under 2 years of age (rapid response)

Date published: May 2026

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• Overview
• What you need to know

Overview

In May 2026, the Public Health Agency of Canada (PHAC) released the National Advisory Committee on Immunization's (NACI) Rapid Response: Update on the Use of Quadrivalent Conjugate Meningococcal Vaccines in Children Under 2 Years of Age. This guidance is based on current evidence and NACI expert opinion.

Meningococcal conjugate C (Men-C-C) vaccines will no longer be available in the Canadian market in the near-future. NACI has developed new guidance in response to this anticipated change in the product environment; also considering the changing patterns of invasive meningococcal disease (IMD) in Canada, and the authorization of new quadrivalent vaccines for infants since the last NACI guidance update for routine programs.

Following a thorough review of the evidence, NACI makes the following recommendations for public health programs:

• For routine programs, NACI strongly recommends that all children 12 to 23 months of age should receive one dose of quadrivalent meningococcal conjugated (Men-C-ACYW) vaccine, regardless of any doses given during the first year of life.
• For programs for individuals at high risk of IMD, NACI strongly recommends that children 6 weeks to 23 months of age who are at high risk of IMD due to an underlying medical condition or increased risk of exposure to serogroups A, C, Y or W should be immunized using a Men-C-ACYW vaccine.
  • The vaccine schedule for these children varies by age. Consult the NACI Rapid Response for details on the recommended vaccine schedules and the list of individuals at high risk of IMD.

For the full statement, please see: Rapid response: Update on the use of quadrivalent conjugate meningococcal vaccines in children under 2 years of age (PDF).

What you need to know

• Invasive meningococcal disease (IMD) is a rare but life-threatening disease that most often manifests as meningococcal meningitis or sepsis. Young children, particularly those under 2 years of age, are at highest risk of IMD, which can cause long-term complications or death.
• Since the early 2000s, Canada's routine meningococcal infant immunization programs against serogroup C have successfully and dramatically reduced the incidence of serogroup C IMD in children under 5 years of age. Replacing the currently recommended Men-C-C vaccines with Men-C-ACYW vaccines will ensure continued protection against serogroup C while providing additional coverage for serogroups W and Y, which now account for nearly half of reported IMD cases in Canada.
• Men-C-ACYW vaccines have been shown in clinical trials to generate strong immune responses in infants and toddlers, including comparable or superior protection against serogroup C to Men-C-C vaccines. The safety profiles for Men-C-ACYW vaccines are similar to other routinely used pediatric vaccines, with reactions mostly mild and short-lived.
• Infants who already received Men-C-C between 12 to 23 months of age are not recommended to be revaccinated with an additional dose of Men-C-ACYW. Depending on the provincial or territorial schedule and the incidence of IMD in their jurisdiction, infants may receive Men-C-ACYW doses before 12 months of age.
• Men-C-ACYW vaccines can be administered concurrently with (i.e. same day as) other routine pediatric vaccines.
• An adolescent Men-C-ACYW vaccine is still needed to ensure there is continued protection during adolescence and young adulthood when the risk of IMD increases again.
• Provinces and territories determine their vaccination programs and policies based on their unique circumstances, including local epidemiology and the timing of their transition away from Men-C-C vaccine supply. Individuals are encouraged to consult a health care provider to see which options are available.

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