University of Minnesota study: Meningitis B vaccine study raises questions about vaccine response in recent New Jersey university outbreak

Wednesday, July 20, 2016

Media note: Watch Nicole Basta, Ph.D., discuss her study findings here

A new study from the University of Minnesota’s School of Public Health finds only 66 percent of college students who received the recommended two doses of the meningococcal group B vaccine Bexsero® (4CMenB) had evidence of a detectable immune response against an outbreak strain.

The study was conducted during an ongoing outbreak at a New Jersey university in 2014. While no cases of meningitis B were reported among the vaccinated students during the outbreak and all vaccinees had evidence they had developed some immunity, the findings suggest the vaccine may have limited impact on certain strains.

The study findings were published online today in the New England Journal of Medicine.

“Epidemiologists play a critical role in evaluating the impact of vaccines,” said Nicole Basta, Ph.D., lead author of the study and assistant professor in the University of Minnesota School of Public Health. “Conducting studies of novel vaccines allows us to go beyond clinical trials and investigate critical questions about how broadly protective new vaccines are. This was a rare opportunity to investigate the immune response to the vaccine during an ongoing outbreak.”

Basta, along with collaborators from Princeton University and Public Health England, evaluated more than 600 blood samples collected both from students who received the recommended two doses of the MenB vaccine and students who chose to remain unvaccinated. By comparing these two groups 8 weeks after vaccination, the team was able to assess the level of immunity to protect against the MenB outbreak strain and two of the strains used to develop the vaccine.

Meningitis is carried by respiratory droplets and oral secretions and is transmitted through close, intimate contact. Meningitis outbreaks can be more common on college and university campuses due to close contact among students living in dorms and other community settings. The use of the MenB vaccine during the New Jersey outbreak was the first ever use of a MenB vaccine in the U.S. The recent licensure of two MenB vaccines provides a new tool to prevent and control MenB outbreaks.

However, the researchers found immunity against the outbreak strain was not as high as immunity against the strains used to develop the vaccine. Basta notes, “We believe our results can be used to help inform policymakers, clinicians, and the public about the potential limitations of 4CMenB-induced immunity. While vaccination remains an important and critical approach to protecting against MenB disease, we observed that not all vaccinees developed detectable immunity against the outbreak strain following vaccination.”

Basta adds their evidence suggests there may be limitations to the breadth of immunity induced by the 4CMenB vaccine, suggesting that people should remain aware of the signs and symptoms of meningococcal disease even if they have been vaccinated.

The study also found:

  • All vaccinated participants exhibited a detectable immune response against at least one of the MenB strains used to develop the vaccine.
  • There was only a moderate correlation between the outbreak strain immune response and the immune response to the similar vaccine reference strain following vaccination.
  • There was no correlation between the outbreak strain immune response and the response to the vaccine reference strain that was not at all similar.

“Our evidence highlights the need for further post-licensure studies to assess individual-level immunity against diverse meningitis B strains and to better understand the breadth of meningitis B vaccine-induced immunity for Bexsero vaccine as well as Trumenba vaccines, now that both MenB vaccines are licensed in the U.S.,” said Basta.

Basta and her colleagues are also conducting long-term follow up with the students vaccinated during the outbreak to assess the duration of immunity induced by this novel vaccine.

"Adolescents, teens and young adults should talk to their doctor about receiving MenB vaccine. While no vaccine is 100 percent effective all of the time, vaccination is a very important tool for preventing MenB disease, which is quite serious and can strike previously healthy individuals without warning."