College Attendance: New Risk Factor for MenB?

College students faced increased risk of contracting serogroup B meningococcal disease (MenB) compared to non-college students, surveillance data from 2014-2016 indicated.

During this period there was a higher risk for sporadic and outbreak-associated MenB disease in college students versus non-college students (RR 3.54, 95% CI 2.21-5.41), reported Sarah A. Mbaeyi, MD, and colleagues at the CDC.

But there was no similar risk observed for serogroups A, C, W, and Y combined in college students versus non-college students (RR 0.56, 95% CI 0.27-1.14), the authors wrote in Pediatrics.

They highlighted the contrast in recommendations from the CDC’s Advisory Committee on Immunization Practices (ACIP) — that quadrivalent meningococcal conjugate vaccine (MenACWY) is currently recommended for all adolescents, but vaccines against meningococcal serogroup B are not “routinely recommended” for all adolescents or college students.

The MenB vaccine may be given “on the basis of clinical decision making,” although the authors said that preliminary data suggests coverage estimates for ≥1 dose of MenB vaccine among youth ages 16-18 was <10% by the end of 2017.

They also noted that both MenACWY and MenB vaccines are recommended for groups “at an increased risk of meningococcal disease,” including during an outbreak. However, the authors added that previous evaluations of epidemiology and risks for meningococcal disease among college students were conducted “when rates of disease were higher, serogroup C was the predominant cause of disease” and the MenACWY and MenB vaccines had not yet become available.

Researchers examined data from the National Notifiable Diseases Surveillance System, and enhanced meningococcal disease surveillance activities from 45 states, representing 98% of the population. College students were defined as individuals ages 18-24 identifying themselves as enrolled at 4-year, 2-year, or technical institutions. “Non-college students” were anyone else in this age group.

Overall, 1,174 confirmed or probable cases of meningococcal disease were reported from 2014 to 2016 in adults ages 18-24, though analyses were conducted on the 163 cases in this age group with known information on college student status. This included 83 college students and 80 non-college students.

The overall incidence of meningococcal disease among adults ages 18-24 was 0.17 cases per 100,000, with the greatest incidence among persons ages 18-20.

In the entire 18-24 cohort, 58.3% of cases were serogroup B. Among college students, 76.9% of cases were serogroup B vs 38.4% of cases in non-college students. About 13% of cases were serogroup C and 10% serogroup Y.

Compared to non-college students, college students with meningococcal disease were more likely to be younger (ages 18-20), and to have received ≥1 dose of MenACWY vaccine.

Six MenB disease outbreaks occurred on college campuses during this time period; about one-third of serogroup B cases were associated with outbreaks. Mbaeyi and colleagues also noted that “no outbreaks due to non-B serogroups were known to have occurred among college students.”

In an accompanying editorial, Lucila Marquez, MD, and Sheldon L. Kaplan, MD, both of Baylor College of Medicine in Houston, wrote that the findings “modify the current understanding of the epidemiology of meningococcal disease.”

They added that when the ACIP deliberated MenB vaccines in June 2015, “college attendance” was not identified as a risk factor for the disease, which was part of the reason that MenB vaccines were given a Category B recommendation.

The editorialists also cited “consequences” for Category B recommendations, including a recent survey that found providers are less likely to recommend a vaccine if it’s not in Category A. Though they added that findings from this study “are unlikely to change” the current recommendation, they argued that these results now give providers “an even more compelling reason” to recommend the MenB vaccine for patients attending college.

“At a minimum, pediatricians should educate students and families regarding the increased risk of MenB infections in college students in the United States and inform them that two vaccines are available that can potentially protect college students from this infection,” Marquez and Kaplan wrote.

One limitation to the data, said Mbaeyi and colleagues, is that they were unable to assess the expected strain coverage of MenB vaccines in this population “because we did not evaluate levels of gene expression and isolate susceptibility to antibodies induced by vaccine antigens.”