The prevention of paediatric bacterial meningitis and septicaemia has recently 
entered a new era with the availability of two vaccines against capsular group B 
meningococcus (MenB). Both of these vaccines are based on sub-capsular proteins 
of the meningococcus, an approach that overcomes the challenges set by the 
poorly immunogenic MenB polysaccharide capsule but adds complexity to predicting 
and measuring the impact of their use. This review describes the development and 
use of MenB vaccines to date, from the use of outer membrane vesicle (OMV) 
vaccines in MenB outbreaks around the world, to emerging evidence on the 
effectiveness of the newly available vaccines. While recent data from the United 
Kingdom supports the potential for protein-based vaccines to provide direct 
protection against MenB disease in immunised children, further research is 
required to understand the breadth and duration of this protection. A more 
detailed understanding of the impact of immunisation with these vaccines on 
nasopharyngeal carriage of the meningococcus is also required, to inform both 
their potential to induce herd immunity and to preferentially select for 
carriage of strains not susceptible to vaccine-induced antibodies. Although a 
full understanding of the potential impact of these vaccines will only be 
possible with this additional information, the availability of new tools to 
prevent the devastating effect of invasive MenB disease is a significant 
breakthrough in the fight against childhood sepsis and meningitis.