First Real-world Evidence of Meningococcal Group B Vaccine, 4CMenB, Protection Against Meningococcal Group W Disease: Prospective Enhanced National Surveillance, England

BACKGROUND4CMenB is a protein-based meningococcal B vaccine, but the vaccine antigens may be present on non-group B meningococci. In September 2015, the UK implemented 4CMenB into the national infant immunization program, alongside an emergency adolescent meningococcal ACWY (MenACWY) program to control a national outbreak of group W (MenW) disease caused by a hypervirulent strain belonging to the ST-11 clonal complex. The adolescent program aimed to provide direct protection for adolescents and indirect protection across the population. METHODSPublic Health England conducts meningococcal disease surveillance in England. MenW cases confirmed during 4 years before and 4 years after implementation of both vaccines were analyzed. Poisson models were constructed to estimate direct protection against MenW disease offered by the infant 4CMenB program along with the indirect impact of the adolescent MenACWY program in children eligible for 4CMenB but not MenACWY. RESULTSModel estimates showed 69% (adjusted incidence rate ratio [aIRR], .31; 95% CI, .20-.67) and 52% (aIRR, .48; 95% CI, .28-.81) fewer MenW cases than predicted among age-cohorts that were fully- and partly-eligible for 4CMenB, respectively. There were 138 MenW cases in