A vaccine for the deadly Meningococcus B has been shown to have 79% effectiveness in patients under the age of 18.
Meningococcus group B is the most common meningococcal infection and until now no studies had demonstrated the effectiveness of the 4CMenB (Bexsero) vaccine over time in the real-world, using a comparison of vaccination rates among cases with closely matched controls.
Researchers in Portugal and the UK, led by the University of Bristol, have now evaluated the vaccine’s performance in a real-world setting and published the findings in the Journal of the American Medical Association (JAMA).
Following the vaccine’s roll-out in the United Kingdom, in 2015 there have been observed reductions in meningococcus group B disease in vaccine-eligible age groups. For this case-control study, the team assessed the effectiveness of the vaccine by analysing the immunisation and medical records of 117 children and young people across 31 paediatric hospitals in Portugal who had the disease between 2014 and 2019.
In the cohort, 98 children had lab-confirmed invasive meningococcal disease, and 69 of these had the group B infection and were old enough to have been fully immunised. Only 7% of this group had received the right number of vaccines doses as compared to 23% of control children who did not have the disease – an observed effectiveness of nearly 80%.
The team was led by Adam Finn, Professor of Paediatrics and Director of the Bristol Children’s Vaccine Centre at Bristol Medical School. He 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.”
The findings showed that of 11 children with meningococcal infection who had received at least one dose of the 4CMenB vaccine, all survived, and none were left with related disabilities, and that in the remaining 87 cases who were unvaccinated, seven died and 16 suffered long term injuries.