A meningococcus B vaccine has 79% effectiveness in children and young adults, according to a new analysis.
The 4CMenB vaccine, also known as Bexsero, was rolled out in the UK in 2015 and included in the childhood immunisation schedule.
Following uptake, meningococcus group B disease cases fell in the vaccine-eligible age group, but no studies had conclusively demonstrated its effectiveness over time in the real-world using comparison of vaccination rates among cases with closely matched controls.
In this study, led by Professor Adam Finn, professor of paediatrics and director of the Bristol Children’s Vaccine Centre at Bristol Medical School, the vaccine was assessed in 117 children and young people across 31 paediatric hospitals in Portugal who had the disease between 2014 and 2019.
The analysis, which also involved a team from Portugal, included 98 children with lab-confirmed invasive meningococcal disease, of whom 69 had group B and were old enough to have been fully immunised.
The findings, published in the Journal of the American Medical Association, show that 7% of this group had received the right number of vaccine doses compared to 23% of control children who did not have the disease, equating to an observed effectiveness of nearly 80%.
There were similar results when all strains of meningococcus were included in the analysis, which could mean the vaccine may provide broader protection than against group B alone.
All 11 children with meningococcal infection who had received at least one dose of the 4CMenB vaccine survived, and none were left with related disabilities.
However, among the 87 cases who were unvaccinated, seven died and 16 suffered long-term injuries.
Prof Finn said: “Although rare, meningococcus group B infection can become life-threatening within hours and can cause long-term disabilities. Young children in particular are more at risk and may die or be seriously harmed even with top quality hospital treatment. This important new study confirms that 4CMenB offers children a very high level of protection against suffering severe outcomes from this potentially deadly infection.”
F M P Rodrigues, Marlow R, Simões MJ et al. Association of use of a Meningococcus Group B Vaccine with Group B Invasive Meningococcal Disease Among Children in Portugal. Journal of the American Medical Association, 1 December 2020
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