US Patent 10328142 Multiple variants of meningococcal protein NMB1870

Meningococcal protein NMB 1870 has been described in the prior art. The inventors have found that NMB 1870 is an effective antigen for eliciting anti-meningococcal antibody responses, and that it is expressed across all meningococcal serogroups. Forty-two different NMB 1870 sequences have been identified, and these group into three variants. Serum raised against a given variant is bactericidal within the same variant group, but is not active against strains which express one of the other two variants i.e. there is intra-variant cross-protection, but not inter-variant cross-protection. For maximum cross-strain efficacy, therefore, the invention uses mixture comprising different variants of NMB 1870.