A major Australian meningococcal B vaccine trial among teenagers has failed to show any discernable impact on throat carriage of Neisseria meningitidis or herd immunity.

Between 2017 and 2018, almost 35,000 SA high school students participated in the largest meningococcal B herd immunity study to date, supported by the vaccine manufacturer GlaxoSmithKline (GSK).

Among the 12,746 year 10 and 11 students who were vaccinated with 4CMenB (Bexsero), throat carriage rates of disease-causing N. meningitidis genogroups, including group B, remained similar to that of the 11,523 students in the control group, at about 2.5%.

The cluster-randomised control trial, involving 237 schools across the state, failed to have a positive effect on the primary outcome, oropharyngeal carriage of disease-causing meningococci or the secondary outcomes, the prevalence and acquisition of all N.meningitidis, the researchers said.