[Meningococcal invasive disease caused by serogroup B in two Chilean children vaccinated against ACWY serogroups].

Invasive meningococcal disease (IMD) by serogroup W has become predominant in Chile since 2012, prompting vaccination with conjugate ACWY. We reported two pediatric cases in patients already vaccinated, which evolved with IMD by serogroup B. This should remind us to keep the alertness with this pathology, despite the current vaccination system in Chile, emphasizing in improve our epidemiological case definition and its diagnosis.