A study in the New England Journal of Medicine yesterday showed the meningitis B (MenB) vaccine, Bexsero, when administered during an outbreak at Princeton University in 2013, produced an immune response in most recipients, but 34% had no immune response to the outbreak strain.
Researchers began administering the vaccine, made by GlaxoSmithKline, at Princeton in December 2013, when a MenB outbreak began on campus. At the time, the multicomponent meningococcal serogroup B vaccine (4CMenB) was approved for use in Europe and Canada (the Food and Drug Administration approved it in 2015).
All 6,000 Princeton students were offered the vaccine, and 89% of students received at least one dose within 2 months of the outbreak. By the end of the 2-year outbreak, there were 9 cases of MenB reported on campus and 1 death.
"We had the unique opportunity to test the vaccine before licensure in US," said Nicole Basta, PhD, MPhil, assistant professor of epidemiology and community health at the University of Minnesota. "All students who were tested had an immune response to at least one strain contained in the vaccine, but a third didn't have any response to the outbreak strain."
Basta and colleagues looked at 499 students who received two doses of the 4CMenB vaccine over 10 weeks. Two months after receiving the second dose of the vaccine, only 66% of subjects showed bactericidal activity against the MenB strain that was infecting students.
"This level of seropositivity was lower than expected, given the antigenic similarity between the outbreak strain and the components of the vaccine and given that the Meningococcal Antigen Typing System predicted that 4CMenB would induce responses against the outbreak strain," the authors wrote.
The authors conclude that a third dose of 4CMenB might increase seropositivity during an outbreak. In an editorial on the study, Jerome Kim, MD, director general of the International Vaccine Institute, said that the 4CMenB vaccine could still be an important public health tool.
"For a relatively uncommon but devastating infectious disease, the regulatory approval of a vaccine in the absence of ideal data may be necessary and appropriate if the vaccine is deployed in the context of a systematic public health response," said Kim.
Though rare, MenB infection can be fatal and can wreak havoc on college campuses. Since 2009, there have been seven outbreaks on college campuses, resulting in 3 deaths and 43 cases. College students are at risk because they live in close quarters, and are known to share food and drink.
Based on the performance of 4CMenB, the Advisory Committee on Immunization Practices, which advises the Centers for Disease Control and Prevention, concluded, "Vaccination of all adolescents would prevent 15 to 29 cases and 5 to 9 deaths annually in the United States."
Even with those small numbers, Basta said she'd recommend the vaccine to teens and young adults, especially those heading to college.
"Meningitis is still pretty rare in the US, but it can be life-threatening."
Jul 20 N Engl J Med study
Jul 20 N Engl J Med editorial