Sepsis and meningitis caused by serogroup B meningococcus are devastating 
diseases of infants and young adults, which cannot yet be prevented by 
vaccination. By genome mining, we discovered GNA1870, a new surface-exposed 
lipoprotein of Neisseria meningitidis that induces high levels of bactericidal 
antibodies. The antigen is expressed by all strains of N. meningitidis tested. 
Sequencing of the gene in 71 strains representative of the genetic and 
geographic diversity of the N. meningitidis population, showed that the protein 
can be divided into three variants. Conservation within each variant ranges 
between 91.6 to 100%, while between the variants the conservation can be as low 
as 62.8%. The level of expression varies between strains, which can be 
classified as high, intermediate, and low expressors. Antibodies against a 
recombinant form of the protein elicit complement-mediated killing of the 
strains that carry the same variant and induce passive protection in the infant 
rat model. Bactericidal titers are highest against those strains expressing high 
yields of the protein; however, even the very low expressors are efficiently 
killed. The novel antigen is a top candidate for the development of a new 
vaccine against meningococcus.