The highest incidence of meningococcal infection in Europe is observed in Norway, and 80% of them are serogroup B cases. (There was an epidemic there in the 1970-80s, and the incidence was 1 in 14-21,000).
A double-blind, randomized study (170,000 people) was conducted on an outer membrane vaccine (OMV). Aluminum hydroxide was used as placebo. Vaccine effectiveness was only 57%, so it was decided not to include it in the immunization schedule.
Between 1990 and 1995, the incidence of pneumococcal bacteremia among adults in Sweden rose 2.6 times. The same thing was observed in Norway.