How Effective is the Meningococcal Conjugate Vaccine Over Time?
Vaccine efficiency began decreasing as soon as 1-year post-vaccination.
HealthDay News—For adolescents, the effectiveness of the one-dose meningococcal (groups A, C, W, and Y) polysaccharide diphtheria toxoid conjugate vaccine (MenACWY-D) decreases at 3 to less than 8 years post-vaccination, according to a study published online in Pediatrics.
Amanda C. Cohn, MD, from the US Centers for Disease Control and Prevention (CDC) in Atlanta, and colleagues conducted a case-control evaluation of vaccine effectiveness (VE) and duration of protection of MenACWY-D. They identified cases of culture- or polymerase chain reaction-confirmed serogroup A, C, W, and Y meningococcal disease among adolescents through meningococcal disease surveillance sites. Per case, the authors attempted to enroll four friend and school controls.
Serogroups C, Y 80, and W 13 accounted for 49%, 44%, and 7% of enrolled cases, respectively. Twenty percent of cases and 44% of controls received MenACWY-D. The researchers found that at 0 to 8 years post-vaccination, the overall VE estimate was 69%: VE was 79%, 69%, and 61%, respectively, at less than 1 year, 1 to less than 3 years, and 3 to less than 8 years. VE was 77% and 51%, respectively, against serogroups C and Y.
"MenACWY-D was effective in the first year after vaccination but effectiveness waned 3 to less than 8 years post-vaccination," the authors write. "The estimates of VE from this evaluation informed the Advisory Committee on Immunization Practices in its decision to add a booster dose of MenACWY."
One author disclosed financial ties to the pharmaceutical industry.
Cohn AC, MacNeil JR, Harrison LH, et al; Active Bacterial Core Surveillence (ABCs) Team and MeningNet Surveillance Partners. Effectiveness and duration of protection of one dose of a meningococcal conjugate vaccine [published online January 18, 2017]. Pediatrics. doi: 10.1542/peds.2016-2193