The Norwegian meningococcal group B outer membrane vesicle vaccine: side effects in phase II trials.

In order to establish the safety of the Norwegian meningococcus B vaccine we have focused on detailed reporting of side effects in several phase II trials. We report here the results of the largest single phase II study, (step II-6) including 877 school children. The incidence of local side effects was significantly higher in the vaccine than in the placebo group, but most of them were mild and short-lasting. Mild systemic side effects were commonly reported in both groups, but more severe side effects were rare and almost equally distributed between the groups.