A vaccine for meningitis has long eluded researchers because the key antigen of the meningococcus B strain has more than 300 sequence variations. Using the three-dimensional crystal structure of this antigen, fHBP, researchers have engineered an antigen that carries the main amino-acid variants and elicits antibodies against all strains of the bacterium in mice.

Rino Rappuoli at Novartis Vaccines and Diagnostics in Siena, Italy, Lucia Banci at the University of Florence, Italy, and their co-workers analysed the sequences of the 300 different types of fHBP. They classified the variants into three main groups and then engineered variants from one group to carry sequences from the other two. They tested 54 engineered fHBPs in mice and one stood out for its ability to induce the production of bacterium-killing antibodies. The authors say it could be used in a vaccine and that the approach could aid in the design of vaccines for other pathogens with many natural variants.

Sci. Transl. Med. 3, 91ra62 (2011)