A MenB (meningococcal B) vaccine is available for use in Europe for the first time. The new vaccine, called Bexsero®, has just received a license from the European Commission. The next stage is for the UK Joint Committee on Vaccination and Immunisation (JCVI) to make a recommendation to the government on whether to introduce the vaccine into the UK schedule.
Meningococcal disease is caused by the bacterium Neisseria meningitidis. It can lead to a range of serious, life-threatening diseases including septicaemia and meningitis. Overall, 1 in 10 cases results in death, while 1 in 5 survivors have permanent effects such as skin scars, limb amputation(s), hearing loss, seizures and brain damage. Following the success of the MenC vaccination program, type B infections account for 90% of the cases of meningococcal disease in the UK. A total of around 750 people in the UK, the majority babies and children, were infected by MenB in 2011, and around 50 of these died.
Vaccines against other strains of the bacterium have been available for many years, but a vaccine against MenB has proved particularly difficult to produce. Polysaccharide vaccines, such as the MenC vaccine used in the UK since 1999, use sugars from the outside of the bacterium to induce the body’s immune system to make a response. But the sugar on the outside of the MenB bacterium is very similar to a particular cell found in the human body, and the immune system does not identify it as foreign and therefore does not attack it. The attempt to create a successful MenB vaccine has focussed on proteins found just under the surface of the bacterium. The problem is that there is a huge variety of different protein strains found across MenB bacteria, so the vaccine has to replicate as many of these as possible in order to protect against a significant number of the bacteria.
We don’t know for certain how many of the cases of meningitis and septicaemia will be covered by this new MenB vaccine. Some studies using laboratory tests have predicted that the vaccine might give protection against around 73% of the MenB bacteria currently circulating in the UK, but we don’t yet know how well the lab test predictions will relate to lives saved or cases prevented. Other research continues, developing and testing different vaccines that might provide higher levels of protection. However, today’s news certainly represents an important step in fighting a disease that kills a large number of children each year, and leaves many more with terrible, life-changing disabilities.