Cases of meningococcal disease currently exceed prepandemic levels.
In March 2024, the CDC released a Health Alert Network Health Advisory warning health care providers that cases of invasive meningococcal disease were on the rise. This increase has been attributed to Neisseria meningitidis serogroup Y—more specifically, the meningococcal strain sequence type 1466.1
Since 2021, cases of meningococcal disease have “increased sharply” in the US, and today, exceed prepandemic levels. There were 422 confirmed and probably cases reported in 2023, the largest number of reported cases in 2014.2
Although meningococcal disease is rare, it can be life threatening, with 10% to 15% fatality rate3—even when patients receive appropriate antibiotic treatment. Vaccines, therefore, are a crucial tool for protection. To date, Penbraya is the only FDA-approved pentavalent vaccine protecting against serotypes ABCWY.4
At IDWeek 2024, 2 posters presented data on additional meningitis vaccines in development. In the first,5 researchers from GSK presented a profile of the company’s pentavalent meningococcal ABCWY vaccine, which was submitted to the FDA for review earlier this year. The MenABCWY vaccine combines antigenic components of the licensed 4-component meningococcal serogroup B vaccine (MenB-4C) and the serogroup ACWY vaccine (MenACWY-CRM).
Investigators presented data from the 12 clinical trials that were part of the vaccine’s clinical development program, inclusive of 7000 adults and adolescents in 13 countries.
Results of one phase 3 study demonstrated that for serogroup B, 2 doses of Men ABCWY 6 months apart was noninferior to 2 doses of MenB-4C 2 months apart. Immunological vaccine effectiveness was 78% when tested against a panel of 110 Men strains (95% CI, 77-79), with serum from 84% of participants killing more than 70% of strains.
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In a comparison of 2 doses of MenABCWY administered 6 months apart with 1 dose of MenACWY-CRM, a group of both MenACWY-primed and MenACWY-naïve patients, MenABCWY was noninferior and demonstrated a robust immune response against each serogroup. Additional data from a phase 2 study of all 5 serogroups showed persistence of antibodies at 2 and 4 years, as well as anamnestic booster responses 2 years after primary MenABCWY vaccination; similar immune responses were noted with the 0- to 6-month and 0- to 11-month MenABCWY vaccination schedules.
Ultimately, the safety and reactogenicity profile of the MenABCWY vaccine was “favorable overall” and consistent with the profile of MenB-4C.
Results of a second poster6 presented safety profile data from a phase 3 clinical study of the MenACWY conjugate vaccine (MenACYW-TT) a quadrivalent meningococcal conjugate vaccine (MenQuadfi), approved for use in children aged 2 years or older. In the study (NCT03673462), investigators compared MenACYW-TT with quadrivalent meningococcal vaccine MenACWY-CRM (Menveo) in healthy infants and toddlers.
A total of 2797 participants were randomly assigned 3:1 to receive either 4 doses of MenACYW-TT (n=2099) or 4 doses of MenACWY-CRM (n=698) at ages 2, 4, 6, and 12 months, coadministered with routine pediatric vaccines. A total of 2458 participants received all 4 doses of their assigned study vaccine.
Within 30 minutes of vaccination, 0.3% of participants in each group reported at least 1 immediate, unsolicited adverse event. Within 7 days, 79% and 77.7% of participants in groups 1 and 2, respectively, experienced at least 1 solicited injection site reaction; 87.1% and 88.2% in each group, respectively, experienced at least 1 solicited systemic reaction.
Over the course of the entire study, 5.2% and 3% of participants in groups 1 and 2, respectively, experienced at least 1 serious adverse event (0.9% and 0.1% reporting at least 1 adverse event of special interest). A total of 76% and 75.5% of participants reported at least 1 medically-attended adverse event. Although 3 deaths were reported in group 1, investigators noted that all serious adverse events, adverse events of special interest, and deaths were “unrelated to the study vaccines.”
As with the first poster, the safety profiles of the 2 vaccines were comparable in healthy infants and toddlers.