Outbreak of invasive meningococcal disease caused by a meningococcus serogroup B in a nursery school, Wallonia, Belgium, 2018, Jacquinet, Stéphanie, Mattheus Wesley, Quoilin Sophie, Wyndham-Thomas Chloé, Martin Charlotte, Van der Linden Dimitri, Mulder André, Frère Julie, and Schirvel Carole , Eurosurveillance, Mar-03-2022, Volume 27, Issue 9, (2022)