College students vaccinated with two doses of meningococcal serogroup B during a university outbreak of meningococcal B experienced a lower level of immunity than expected, according to recently published findings.
“Although the incidence has been declining, in part because of the routine administration of meningococcal A, C, W and Y vaccines in adolescents, the prevention of serogroup B disease has presented particular challenges; it is possible to use the meningococcal B polysaccharide as a vaccine antigen owing to its similarity to human glycoproteins, the presence of which could lead to an autoimmune response,” Nicole E. Basta, PhD, assistant professor of epidemiology and community health in the School of Public Health at University of Minnesota, and colleagues wrote. “Meningococcal B vaccines that are derived from the outer-membrane vesicles of specific outbreak strains have been developed, but these vaccines have not provided broad protection beyond the outbreak strain.”
Basta and colleagues conducted a seroprevalence survey that included 499 students at a U.S. university who had been vaccinated with multicomponent meningococcal serogroup B (4CMenB; Bexsero, Novartis/GlaxoSmithKline) prior to its FDA licensure in December 2013 in response to an exposure of Neisseria meningitidis B on campus. The survey was given 4 months after 4CMenB exposure to examine the vaccination status and collect serum specimens to assess the number of serum bacterial antibodies (SBA) with an assay including human complement (hSBA). The researchers extracted serum from participants’ previously stored blood samples and compared those with unvaccinated participants who were seropositive for N. meningitidis B strain, for 44/76-SL closely related strain and 5/99 mismatched strain. An hSBA titer of 4 or higher was considered seropositive. Survey participants completed 18 questions and provided access to their vaccination records.
Comparison analysis showed that 66.1% (95% CI, 61.8-70.3) were seropositive for the exposure strain among the 499 participants who were vaccinated with two doses of 4CMenB 10 weeks apart. A positive correlation was present between the response to the exposure strain and the response to the 44/76-SL strain (Pearson correlation, 0.64; P < .001), and no correlation was present compared with the response with the 5/99 strain (Pearson correlation, –0.06; P = .43).
“These findings have implications for vaccination policies aimed at preventing and controlling meningococcal B disease,” the researchers wrote. “The Advisory Committee on Immunization Practices voted for a category A recommendation for meningococcal B vaccine for those 10 years of age or older who are at an increased risk for disease and a category B recommendation for those 16 to 23 years of age for short-term protection against most strains causing disease.” – by Kate Sherrer
Disclosure: Basta reports receiving grants from Princeton University, the NIH and the Research and Policy for Infectious Disease Dynamics Program. Please see the full study for a list of all other authors’ relevant financial disclosures.